The most common type of heat pump, called an air-source heat pump, works by absorbing heat from the air and moving it either from outdoors to indoors (in heating mode) or vice versa (in cooling mode). It’s the same way an air conditioner works, and in cooling mode, air-source heat pumps work identically to ACs. The two types of appliances look similar, are generally manufactured by the same companies, and use almost all the same parts. Heat pumps just have a few small differences that allow them to move heat in two directions, in and out.
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Until relatively recently, air-source heat pumps were predominantly used only in the southern U.S., where they’re a natural fit for hot summers and mild winters. But the technology has improved, making air-source heat pumps a practical choice almost anywhere in the country, even in places with cold winters. As counterintuitive as it seems, there’s always some free heat energy in the air, even on frigid winter days. Today’s cold-climate heat pumps can efficiently collect that free heat and move it into your home.
That’s why heat pumps offer a lower-carbon way to heat your home than other options, even if they run on electricity that’s mostly generated by fossil fuels. When they’re powered by renewable energy, whether that’s solar or a cleaner grid, they become even more sustainable. Because of their energy savings and environmental benefits, some states and utility companies offer rebates or other incentives to homeowners who install heat pumps.
You can use a heat pump as the sole heating and cooling appliance in your home or combine a heat pump with an existing heating system. Many homes with existing ductwork for forced-air HVAC systems can be adapted to heat pumps. Ductless heat pump systems, called mini-splits, can provide heating and cooling in a home without ducts or add climate control to rooms that the main system doesn’t reach.
Living with a heat pump is a bit different from using a traditional heating system. A modern heat pump is most efficient when your thermostat is set at a constant temperature. It actually saves energy if you don’t turn it down overnight. They also blow cooler air than furnaces and run almost constantly at a low level rather than blasting heat for short periods throughout the day. Good insulation and air sealing of your home and duct system are important regardless of how you heat your home, but they’re even more beneficial with heat pumps.
In the U.S., we typically use air-source heat pumps and, most often, a subset known as air-to-air heat pumps. That means they absorb and release heat from the air (rather than water or earth) and deliver heating or cooling to homes through a forced-air system (rather than radiators). Among air-to-air heat pumps, two types are most common in residential homes.
Ducted Air-Source Heat Pumps
This type of heat pump looks and operates a lot like a central AC. There’s an outdoor unit and an indoor unit, both of which have aluminum fins and coils to release or collect heat, connected by a refrigerant line filled with fluid that transports heat between the two units. The outdoor unit also has a compressor, which compresses and circulates the refrigerant. The indoor unit hooks up to ducts inside your home, and a blower circulates the warm or cool air through those ducts and out of air vents placed around your house. According to CR’s member surveys, the overall median price paid for the purchase and installation of a ducted heat pump between and was $8,348. Most homeowners choose a 3-ton-capacity heat pump, which is good for about a 2,000-square-foot home, according to HomeAdvisor, a home-improvement services marketplace.
Ductless (aka Mini-Split) Air-Source Heat Pumps
This is a common, straightforward way to add a heat pump to a house or section of a house that doesn’t have ducts. Instead of relying on ductwork to move warm or cold air through a house, it connects to one or more individual indoor air handlers, or “heads,” which are installed throughout the home. The air-handler heads are usually placed high on a wall, but for homeowners who don’t like the look or don’t have the space, there are heads that can be placed inside the ceiling or floor. Mini-splits are also more energy-efficient than ducted heat pumps because they avoid the energy losses associated with ductwork. CR doesn’t have enough brand-specific data yet to report on the prices members paid to purchase and install ductless mini-splits. According to HomeAdvisor, the average cost to install one unit is $3,000, but the price could range from $2,000 to $6,000 depending on how it’s mounted and installed. For multiple mini-splits, plan to spend up to about $14,500, depending on home size, heat pump capacity, type of heat pump, and how many units you choose.
Other Types of Heat Pumps
There are a few other types of heat pumps that have proved to work well in some situations but are less common than air-source heat pumps.
Ground-source or geothermal heat pumps absorb and release heat underground, where the temperature is a constant 50° F to 60° F all year. They are highly efficient because they don’t have to compensate for big temperature swings the way air-source heat pumps do. But because the heat-exchanging pipes are buried underground (either horizontally or vertically), ground-source systems can be impractical for small lots or those with certain types of soil or landscapes. Ground-source systems can cost from $6,000 to $30,000 or more. Federal and local incentives can reduce the cost significantly, and the systems are so energy-efficient that the savings from your utility bills could offset the cost of installation within 10 years, even by conservative estimates.
Water-source heat pumps work like ground-source systems, except they’re laid at the bottom of a pond rather than underground. If you have an appropriate body of water on your property, these can be easier and less expensive to install than ground-source systems.
Air-to-water heat pumps use outdoor units similar to air-to-air models, but they distribute heat through a hot-water radiator system. They’re common in much of Europe but not currently in the U.S., even though many homes in the Northeast and Midwest rely on hydronic radiators for heat.
You already have one and need to replace it. If your home already relies on a heat pump and you’re happy with it, the simplest thing to do when it wears out (generally after 10 to 15 years of service) is to replace it with a similar model, which will likely be more efficient. CR members can see which brands of ducted heat pumps make their owners the happiest, based on data we’ve collected from our member survey.
You need to replace your central AC (or add new built-in air conditioning). In cooling mode, a heat pump works exactly like an air conditioner. The installation process for both systems is essentially the same, too. The cost of installing a heat pump tends to be higher than it is for installing a central AC with a similar efficiency rating and capacity, though the exact amount can vary. Some state governments and utility companies offer tax incentives or cash rebates if you install a heat pump, mitigating some of the cost.
So if you’re replacing (or adding) an AC anyway, whether it’s a central system or a room unit, it may make sense to pay a little extra for a heat pump and keep your existing heating system as a backup for the coldest days and reap the rewards of high-efficiency heating on the milder days of the year. (More on this kind of hybrid system later.)
You want to add heat to a chilly room. A ductless mini-split heat pump is an affordable and effective way to add climate control to parts of your house where the main system may not reach—such as a finished attic, garage workshop, or home addition.
You heat with “delivered” fuels like propane or heating oil, an electric-resistance furnace, or electric baseboard heaters. These are all expensive ways to heat a home, and depending on such factors as where you live and the cost of electricity, you’re likely to save money over time if you switch to a heat pump, even when you include the cost of installing it.
You want to significantly reduce your carbon footprint. Almost half of a typical home’s energy use goes toward heating. So anything you do to heat more efficiently, and with cleaner sources of energy, will go a long way toward making your home more sustainable. Switching from a gas furnace to an electric-powered heat pump will reduce a home’s heating-related carbon emissions by an average of 40 percent, according to a study from the University of California, Davis. It’s one of the most impactful ways to reduce your carbon footprint, and it doesn’t require a lifestyle change.
Your home has ductwork. More than half of all homes in the U.S. already use ducts to distribute heating and cooling. A ducted heat pump can be connected to the existing ductwork to provide whole-home heating and cooling. The only caveat: Leaky, uninsulated ducts are bad for any heating system, but especially for heat pumps.
You live somewhere with heat pump subsidies. Heat pumps—particularly models that work well in very cold climates—may cost more upfront than other types of heating appliances. For example, CR members surveyed paid a median price of $8,348 to purchase and install a heat pump vs. $6,221 for gas furnaces. And sources we spoke to said whole-house heat pumps for cold climates can easily cost more than $10,000. But with state or utility-based subsidies, such as tax incentives or cash rebates, a heat pump can cost less than other heat-only systems. That’s especially true when combined with the federal tax credit.
Heat pumps aren’t the most practical heating solution for every house. Here are some cases in which it can be expensive, difficult, or impossible to install one.
Your house has no ducts. It can be difficult and expensive to add ducts to a home that doesn’t have them, and heat pumps built to work with hydronic heating systems are uncommon and expensive in the U.S. In this case, a ductless mini-split system is usually the easiest way to add a heat pump.
Your house is poorly insulated or leaky. If yours is an older home, it’s always a good idea to first upgrade your insulation and seal any air leaks, regardless of how you heat the house. It’s also wise to wrap and seal your ductwork, if you have any. Good insulation is especially beneficial in homes that use heat pumps. Heat pumps heat more gently than other systems; it’s a constant trickle of warm air rather than blasts of heat every few hours. If you have poor insulation, you’ll notice drafts and cold spots more often than you would with the higher temps of a traditional system. Keep in mind, though, that you can offset the cost of improving your home’s insulation with another federal tax credit worth up to $1,200.
Your electrical service is underpowered. Some homes, particularly older ones, have only 100-amp or even 60-amp electrical service. Technically you can run a heat pump on a system like this, especially if it’s a smaller-capacity mini-split. But if it’s a bigger heat pump and you turn on too many additional appliances—or plug in an electric vehicle—you could trip the breaker and have to reset your system. If you have your heat pump professionally installed, a good contractor will check your panel for capacity and may advise hiring an electrician to upgrade to the modern standard of 200 amps. That work could cost a couple thousand dollars. But it can be offset by up to $600 through the same federal tax credit used for insulation upgrades. (The annual limits vary depending on the upgrade.)
You live in an extremely cold climate. The Department of Energy divides the U.S. into eight climate zones. The higher the number, the colder the winters. Basic heat pumps have been common in the lower-numbered zones for decades. Modern heat pumps in a properly designed system can provide all the heat a home will need up through zone 6.
In zones 7 and 8—which include the northern parts of North Dakota, Minnesota, Wisconsin, Michigan, Maine, and all of Alaska, where temperatures can drop below -25° F for days at a time—even today’s cold-climate heat pumps might not provide adequate heat. You’re likely to need a backup heating system if you live in one of those areas.
Size (Capacity)
A heat pump that’s too small for your needs will struggle to keep your home comfortable. On the other hand, an oversized unit will cost more, and if it isn’t a variable-speed model, it will cycle on and off more often than it should. This decreases efficiency, stresses components, and leaves your home less comfortable.
A heat pump’s cooling capacity is measured in British thermal units per hour. Btu/hr. can also be expressed in “tons,” with 1 ton equaling 12,000 Btu/hr. To ensure that your heat pump is sized correctly, make sure your contractor does a load calculation based on a recognized method, such as the Air Conditioning Contractors of America (ACCA) Manual J. The calculations should be done after any air-sealing or insulation upgrades are made to your home and should be done whether you’re replacing a unit or installing a new system.
If you’re planning to keep a backup heating system alongside your heat pump, consider getting an undersized heat pump. A contractor can help you figure out whether this makes sense in your home.
If you’re switching from a furnace or boiler, note that heat pumps need far less capacity to heat a space because they’re much more energy-efficient. For example, if your home needs a 100,000-Btu/hr. furnace, it may need only a 36,000-Btu/hr. heat pump.
Compressor Type
The compressor is the heart of a heat pump—it’s the part that actually pumps the heat. Basic heat pumps have a single-speed compressor. It’s either on or off. This system works well enough, but the temperature and relative humidity in your home will swing up and down with the cycles. Compressors with two speeds make the swings better but still don’t prevent the ups and downs.
The gold standard is a variable-speed compressor. It’s designed to run almost constantly, adjusting itself over time to deliver only as much heating or cooling as it takes to keep your home comfortable. It’s also much better at keeping relative humidity under control than single-speed models are. Variable-speed compressors not only keep your home more comfortable but also are more energy-efficient. It may seem counterintuitive, but it takes much less energy to move a tiny bit of heat all the time than to move a lot of heat quickly.
Efficiency
Some heat pumps use less energy than others to deliver the same level of comfort. In cooling mode, efficiency is commonly expressed as the seasonal energy-efficiency rating (SEER). The higher the SEER, the greater the efficiency. In heating mode, the measurement used is the heating seasonal performance factor (HSPF). Again, the higher the number, the more energy-efficient the unit.
As of January , the Department of Energy adopted new testing methods for energy efficiency, replacing the SEER and HSPF values with SEER2 and HSPF2.
Heat pumps with higher energy efficiency ratings tend to cost more, but they’ll often pay for themselves over time through lower energy costs, and they may be eligible for better tax incentives or rebates than less efficient models. Heat pumps with higher SEER ratings also tend to have higher HSPF ratings, though there’s no direct relationship between the two. If you live in a warm climate, pay closer attention to the SEER. In cold climates, look for a higher HSPF.
Climate Performance
If you live in a region with cold winters, you’ll need to either pick a heat pump that’s rated to work well in the lowest temperatures that your region regularly experiences or have a secondary heating system to back up your heat pump.
All air-source heat pumps struggle to perform as temperatures drop; the space they can effectively heat shrinks and they don’t work as efficiently. The threshold for poor performance varies from model to model. Some heat pumps falter at 25° F, others at 17° F or lower.
Models marketed as cold-climate heat pumps can work to their full potential all the way down to 5° F and may deliver some heat even down to -20° F or lower. The best course is to work with a qualified local contractor who knows what kind of equipment works well in your area.
If you live in an area where the temperature rarely or never drops below freezing (32° F), a basic heat pump can handle the bulk of your heating and cooling needs. You can keep a simple electrical-resistance backup system (sometimes built into the heat pump itself) for unusual cold snaps.
Noise
Manufacturers publish the noise levels of their products in the user manual and often on their websites. They tend to include noise estimates across a variety of outdoor temperatures and fan speeds, measured in decibels. A lower number is better, especially if the heat pump will be installed near a bedroom window.
Reliability
In our member survey, heat pumps from eight brands were judged highly reliable, but only two of them also got top marks for owner satisfaction. Consumer Reports members can see the predicted reliability and owner satisfaction ratings for 29 brands of heat pumps, based on data that CR members have shared about 10,158 heat pumps they bought new and installed in their own homes between and . Those findings are summarized in our guide to the Most and Least Reliable Heat Pumps.
As with most heating and cooling systems, it’s wise to hire a professional to handle the design and installation of a new heat pump system. The margin for error with heat pumps is smaller than with traditional heating systems, making proper sizing essential. Here are some tips for hiring a good installer.
Ask around. Seek referrals from neighbors, family members, business associates, or local green-energy resource groups. It’s wise to get price quotes from at least three contractors.
Check their background. Contractors who bid on your installation should show you verification of bonding and insurance, plus any required contractor’s licenses. Check with your local Better Business Bureau and consumer affairs office for complaint records. It’s a plus if technicians are certified by a trade organization, such as North American Technician Excellence or HVAC Excellence, to service residential heating and cooling equipment. Those and similar programs assess the technician’s knowledge of specific types of equipment and their proper service methods.
Get specific calculations. Be wary of a contractor who bases estimates merely on house size or vague rules. Contractors who bid on your job should calculate the required heating and cooling capacity using a recognized method, such as one found in the ACCA’s Residential Load Calculation Manual, also called Manual J. An additional reference for assessing ductwork needs is Manual D. The calculations produce a detailed, room-by-room analysis of heating and cooling needs. Ask for a printout of all calculations and assumptions, including ductwork design.
Make sure your installer scopes out a proper location for the outdoor unit. A compressor needs adequate airflow to operate correctly. Make sure to keep at least 2 to 3 feet of space between the unit and any plants or structures. There should also be 5 feet of clearance between the top of the unit and any trees above. You’ll also want to make sure there’s enough space for you or a technician to access and service the unit. And local building codes might have regulations about how close an outdoor compressor is allowed to be from a neighbor’s window or property line.
If you have experience with electrical, plumbing, and carpentry work, you could save money by installing a mini-split system yourself. Do-it-yourself systems are on the market, and numerous online videos explain what to do. But even with a DIY kit, you’ll need to drill a hole several inches through your exterior wall for the refrigerant, drain tubing, and control lines.
Keep in mind, too, that your municipality may require several permits, including a licensed electrician to do the electrical work.
With the right heat pump and system design for your home and regional climate, a backup heating system shouldn’t be necessary.
But in cold climates, keeping a backup system can be the most cost-effective way to keep your home comfortable. You could even think of it as a hybrid setup rather than a system with a backup. You’ll use the heat pump most of the time (including in the summer, when it provides all your cooling) and the backup system only on the coldest days when the heat pump can’t keep up. A contractor can set up the system to switch automatically at a specific outdoor temperature.
Hybrid systems still save a ton of energy and carbon emissions compared with most other setups and can offer some peace of mind in colder climates.
Here are a few common types of hybrid setups.
Electric strip: Common in mild climates, a simple electric heating element can be built into the heat pump itself or the indoor air handler. These strips use a ton of energy, but they’re very inexpensive to install and maintain, and it’s a cost-effective way to get through short cold snaps.
Mini-split plus radiators: Radiator systems that run on oil or propane, or “regular” electric-resistance heat, tend to be expensive to run, but mini-split systems that are big enough to heat your entire home tend to be expensive to install. A popular compromise: Install a smaller mini-split that can handle most of your heating (and cooling) needs and keep the old radiator system for the coldest days.
Ducted heat pump plus furnace: It’s the same concept as the mini-split and radiator combo above. You’ll install the heat pump just like you’d install a central AC.
ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
focusonenergy.com • 800.762.
TABLE OF CONTENTS Introduction...................................................................................................................3 How Much Will I Save On My Heating Bill?.........................................................3 How Does A Heat Pump Work?.............................................................................4 What Type Of Heat Pump Is Right For My Home?...........................................5 Existing Homes...................................................................................................6 New Homes........................................................................................................10 Buying A Heat Pump?...............................................................................................11 How Much Will It Cost?....................................................................................11 How Do I Buy A Heat Pump?........................................................................12 Paying For A Heat Pump.........................................................................................14 Best Practices For Using & Maintaining Your Heat Pump............................15 Controlling Your Heat Pump..................................................................................17 How Heat Pumps Work & Other Types of Heat Pumps................................19 The Science Behind Heat Pumps...............................................................19 Other Types Of Heat Pumps........................................................................20 Air Source Heat Pump FAQs & Myths...............................................................22 Glossary....................................................................................................................... 27 Resources...................................................................................................................29
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
INTRODUCTION
On average, more than half the energy you use goes to heating and cooling your home. That’s why it’s important to choose a heating and cooling system that will save energy and money, while keeping your family comfortable for years to come. Heat pump technology is an option for high efficiency heating and cooling. A heat pump system can complement, or even be a great alternative to, a traditional furnace or other heating equipment. It also provides a simple way to introduce air conditioning to your home. What’s a heat pump? It is as simple as it sounds. A heat pump, pumps heat. It mechanically transfers heat from outside and moves it indoors to heat your home – or in reverse to pull heat from your home to cool it down. Heat pumps are common – so common, in fact, you have lived with one in your home your entire life! It is not typically referred to as a heat pump, but using the same basic heat pump process, your refrigerator extracts heat from inside the refrigerator and expels it outside the unit to keep your food cold. This is the warm air you feel coming from the back of your refrigerator. So, What Are The Benefits Of A Heat Pump? Efficient. Heat pumps can use considerably less energy to heat and cool a home, all year long. They’re two to four times more efficient than electric resistance or fuel burning systems. Less energy used more efficiently could mean the potential for high savings on your energy bills if you heat your home with electric baseboards, oil, or propane. Convenient. Since a heat pump system is powered by electricity, you won’t spend time filling tanks, splitting and hauling wood, or dealing with the risk of fuel shortages. Flexible Comfort. A heat pump allows for a variety of configurations to complement your existing heating system. They can also provide heating and cooling to just the uncomfortable areas in your home. Healthier. Heat pumps may offer both air filtration and dehumidification, keeping a home’s air cleaner and reducing the likelihood of mold and mildew. Cleaner. Electric-powered heat pumps produce zero emissions on-site. Heat pumps can utilize renewable energy sources like wind and solar, thereby reducing a home’s environmental impact. As the electric grid likely gets cleaner over the next decade, your heat pump operation will get cleaner too.
HOW MUCH WILL I SAVE ON MY HEATING BILL?
A home’s savings depends on the type of heat pump selected, current source of heating fuel, age of home, and amount of insulation, among other factors. Homeowners who switch from electric baseboard heating to a heat pump can see drastic reductions of 50% or more in their electric bills during the winter. In summer, you will likely see additional savings compared to conventional air conditioners. If you don’t heat with electric resistance, your electric bill will go up, but other heating fuel costs will go down. Oil or propane users can see up to 50% net savings on their average yearly heating costs. Homeowners are likely to experience higher energy bills if converting from natural gas to an all-electric system. Including weatherization upgrades will increase savings on your heating bill too.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
HOW DOES A HEAT PUMP WORK?
According to the Department of Energy, air source heat pumps (ASHPs) are the most common heat pump. With this type of heat pump, the heat is transferred between your home and the outdoor air. As you’ll see in this guide, there are many configurations of air source heat pumps, so be sure to talk to your contractor to determine which one will work best for your home. Unlike a gas furnace or wood burning stove, heat pumps don’t create heat; instead, they move heat from one place to another. This is possible because heat energy is naturally present in the earth and air, even when it is cold outside. Essentially, a heat pump functions as an air conditioner that can also work in reverse. In the summer, as shown in Figure 1, the equipment moves heat from inside to outside the home; and in the winter, as shown in Figure 2, heat is extracted from the air outside and moved inside the home. This is also the same technology that your refrigerator uses to keep your food cold.
FIGURE 1: HEAT PUMP – COOLING MODE
FIGURE 2: HEAT PUMP – HEATING MODE
A heat pump will consistently maintain the desired temperature throughout your home by providing a constant stream of air at a low volume for long periods of time. You may not hear the unit operate or feel blasts of hot air in the winter, but as long as your thermostat shows the desired temperature you can be sure it’s working! Not Your Grandpa’s Heat Pump. Tremendous improvements in technology in the past 30+ years—such as variable speed drive motors (also called inverter-driven compressors)—have rendered a new generation of air source heat pumps that can deliver heat more efficiently and reliably at much lower temperatures. The compressor is the “engine” of the heat pump, and with the ability to vary speed, it offers benefits much like a multi-speed bicycle compared to a single-speed bicycle. In contrast to single- and two-stage compressors, variable speed compressors can run at higher speeds when it’s cold outside and can run at lower speeds during the summer and during days with moderately cold temperatures.
SINGLE-STAGE: Heat pump that has limited flexibility since it only runs at 100% capacity.
TWO-STAGE: Heat pump that has two distinct stages of heating and cooling; typically high capacity of 100% and low capacity around 70%.
VARIABLE SPEED: Heat pump that uses an inverter motor to allow for a full range of operation.
This operates like a car’s accelerator in that the heat pump finds the right speed to run most efficiently.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME?
The type of heat pump that makes the most sense depends on your situation. The biggest factor is whether your home already has central ductwork. If you think a heat pump is right for your home, the following scenarios can help you choose the right one. Talk to your contractor to be sure you get the heat pump that matches your goals and home needs.
1 2
HOW MUCH OF YOUR HOME NEEDS HEATING AND OR COOLING? DOES YOUR HOME HAVE DUCTWORK? If you have grates or registers that deliver warm air, you have ductwork. WHAT TYPE OF FUEL DO YOU USE TO HEAT YOUR HOME? The heat pump configuration listed under your fuel is likely the best option for your home.
I WANT TO HEAT MY ENTIRE HOME
I WANT TO HEAT JUST ONE OR A FEW ROOMS
DUCTS NOT APPLICABLE
YES, I HAVE DUCTWORK
NO, I DO NOT HAVE DUCTS
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NATURAL GAS
NATURAL GAS
DUAL-FUEL HEAT PUMP Uses electricity when it’s mild out and natural gas when it gets very cold.
DUCTLESS HEAT PUMP(S) Focuses heating and cooling where its needed most.
ELECTRIC
ELECTRIC
COLD CLIMATE HEAT PUMP Can cover all your heating and cooling needs, even on the coldest days.
DUCTLESS COLD CLIMATE HEAT PUMP
Can cover all your heating and cooling needs, even on the coldest days.
BUILDING A NEW HOME?
LIQUID PROPANE/OIL
LIQUID PROPANE/OIL
DUAL-FUEL HEAT PUMP
You have a lot of options! Heat pumps are versatile and can provide heating and cooling options for nearly any scenario. Talk to your builder to see which option will work best.
DUCTLESS HEAT PUMP(S) Focuses heating and cooling where its needed most.
Uses electricity when it’s mild out and LP/oil when it gets very cold.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME? EXISTING HOMES
Entire Home with Existing Central Ductwork CURRENT HEATING FUEL TYPE
Natural Gas
LP or Oil
Electric
RECOMMENDED HEAT PUMP CONFIGURATION
Ducted, Cold Climate, All Electric
Ducted, Dual-fuel
Ducted, Dual-fuel
This will all you to take advantage of current low gas prices. You can see some heating bill savings right away and have the flexibility to use the heat pump more if your electric prices go down or natural gas prices go up.
This will greatly reduce your need for costly LP or oil. Your LP/oil bill will be significantly reduced while your electric bill will go up slightly. Your overall heating costs may be reduced by 50%.
Your electric bill will be significantly reduced, up to 55% in the winter.
If your home already has a furnace and ductwork, it may make sense to install a centrally-ducted heat pump that supplements, or even fully replaces, the furnace. When the heat pump is being used, the furnace functions simply as an air handler, as shown in Figure 3, to move air through the ductwork. These options are good when you need to replace your entire HVAC system or furnace or if you want to reduce your reliance on propane or fuel oil. More advanced controls are now available that will determine when the heat pump should operate, and when your backup, also known as supplemental, heating system will start, based on your current fuel prices - leaving you with little to worry about. One thing to keep in mind is that not all thermostats are able to control a heat pump. Heat pump specific thermostats may need to be used to take full advantage of all their features and capabilities. Be sure to work with your contractor to ensure you have the right controls for your heat pump. Learn more about heat pump controls in the Controlling Your Heat Pump section.
Figure 3: Ducted heat pumps use the same ductwork a furnace or central air conditioner to deliver conditioned air. If you have grates or registers that deliver warm or cool air, you have a ducted system.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME? EXISTING HOMES
BACKUP HEATING FOR ENTIRE HOME SYSTEMS
Dual-Fuel: Natural Gas
Dual-Fuel: LP or Oil
All Electric
A system with natural gas for backup heating. Like a central air conditioner, in this configuration, the heat pump is attached to the gas furnace. Conveniently, centrally ducted heat pump systems can easily integrate with most newer furnaces, just like a central air conditioner would. In the winter, when the outdoor air cools to a predetermined temperature, the electric heat pump shuts off and the gas furnace takes over— supplying heat as usual. Due to the current relatively low cost of natural gas, the temperature at which to use your furnace will be higher, around 40-50°F.
A system with oil or propane for backup heating. Like a central air conditioner, in this configuration, the heat pump is attached to the gas furnace. Conveniently, centrally ducted heat pump systems can easily integrate with most newer furnaces, just like a central air conditioner would. In the winter, when the outdoor air cools to a predetermined temperature, the electric heat pump shuts off and the gas furnace takes over— supplying heat as usual. Due to the higher cost of LP and oil, the temperature at which you use your furnace may be around 15-20°F.
All-electric ducted heat pumps can have add-on electric resistance coil heaters that easily integrate and operate simultaneously with the heat pump. This allows the heat pump to provide 100% of a home’s heating needs on the coldest days. If your goal is to eliminate gas entirely, this is a good option. An existing gas furnace would be completely replaced with the new heat pump and air handler.
C old climate heat pumps. These heat pumps have more capacity to heat your home at low outdoor temperatures than standard air source heat pumps. Cold climate heat pumps have a variable speed inverter-driven compressor allowing the unit to continue providing efficient heat in freezing temperatures. If you already heat with electricity or want to completely replace your fuel burning furnace and go all electric, a cold climate heat pump is your best option. If you want to keep your fuel-burning furnace as backup, dual-fuel cold climate heat pumps give you the flexibility to offset as little or as much fuel as you’d like. Cold climate models maintain significant heating capacity and can perform efficiently down to -15°F according to manufacturer’s ratings or even -20°F according to research data. If cold-temperature performance is important to you, you can visit the ENERGY STAR® website energystar.gov or ashp.neep.org to verify an air source heat pump is listed as a cold climate model. D o you want to add air conditioning, or do you need to replace an old AC? A heat pump is a great option to introduce highly efficient cooling to your home. A heat pump will allow you to cool your home in the summer and provide some, or most, of your heating needs in the winter. You’ll still be able to keep your current heating system in place to be used as a backup when needed.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME? EXISTING HOMES
Entire Home Without Existing Central Ductwork CURRENT HEATING FUEL TYPE
Natural Gas
LP or Oil
Electric
RECOMMENDED HEAT PUMP CONFIGURATION
Ductless, mini-split (multiple)
Your natural gas bill will be reduced while your electric bill will go up.
Your fuel bill will be reduced while your electric bill will go up. Your overall heating costs may be reduced by 50%.
Your electric bill will be significantly reduced, up to 60% in the winter.
From one or two zones focusing heating and cooling where they are needed the most, to a more comprehensive system covering the entire house, a ductless mini-split system can improve your comfort, reduce energy costs, and add air conditioning at the same time. Ductless mini-split systems can be 15%-20% more efficient than ducted systems because a large blower motor is not needed to blow conditioned air throughout the home, and air leakage in the ductwork is eliminated. These systems are also a good option for manufactured homes or reducing your reliance on propane or fuel oil. As shown in Figure 4, a ductless system typically covers
a single area (or zone) of your home. A home can have several, separate single-zone systems. Ductless systems with more than one indoor unit (multi-zone) allow for consistent temperature settings throughout different areas of the home. Ductless mini-split systems can provide optimum comfort for your entire family while ensuring you don’t waste energy where you don’t need it. A typical entire-home configuration may consist of one outdoor unit and two to five ductless indoor units (multi-split) , or a combination with one or two ductless indoor and outdoor units and a compact-ducted system for the bedrooms. If you currently have a boiler, an entire-home system is often the best option. You can use your boiler for backup heat when necessary, as described below. Figure 4: Ductless heat pumps, also called mini-splits, do not need ductwork. Instead, they directly provide conditioned air to an area, or room, with indoor units. These units come in a variety of styles and can be mounted on the wall, in the ceiling, or on the floor. There can be multiple indoor units for each outdoor unit. The needs of your home may require multiple outdoor units.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME? EXISTING HOMES
Installing a mini-split is typically quick and nonintrusive. A contractor can usually complete installation in less than one day. Only a small three-inch hole in an exterior wall is needed to connect the refrigerant line from the outdoor unit to the indoor unit. Power only needs to be provided to the outdoor unit and most units require a 240-volt 20-Amp
circuit. Systems with multiple indoor units may require multiple outdoor units. Backup Heat for Homes Without Central Ductwork
Backup heating can be provided from a variety of sources, such as an existing boiler, electric baseboards, or wood burning stoves. Replacing existing systems can be done with a single unit as shown below in Figure 5. In this example the bedrooms are too small to have their own heat pumps. The heat pump will provide heat to the main areas of the home while the backup heat source will provide heat in the hard-to-reach areas. Learn more about heat pump controls in the Controlling Your Heat Pump section.
FIGURE 5: (left) Home using only baseboard electric heat. (right) Home after installing ductless mini-split with one indoor unit. The electric baseboard can be left in place as the backup heating source for rooms that are uncomfortable.
One Room or Area, With or Without Existing Central Ductwork FUEL TYPE
Natural Gas
LP or Oil
Electric
RECOMMENDED HEAT PUMP CONFIGURATION
Ductless, mini-split (single)
Do you have one room or area of the house that is never comfortable, such as a room over a garage or a basement space? Or are you planning an addition and it’s just not physically feasible or too expensive to get ductwork to the addition? In these scenarios, a single ductless mini-split unit may be a great choice for heating and cooling. See the previous section on ductless systems for more information.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
Recommended Heat Pump Types: Air Source, Ground Source, Air-to-Water WHAT TYPE OF HEAT PUMP IS RIGHT FOR MY HOME? NEW HOMES
H eat pumps are an excellent choice for new homes and major rehabs. If it’s a smaller house, often just one or two mini-split systems can do the job. If you have a large-sized property, you may consider a ground source heat pump (GSHP) which is the most energy efficient of all heat pump types. However, ground source heat pumps are expensive and involve a more intensive installation for the underground components. Ground source heat pumps can be installed as a ducted or ductless system. G SHPs, also known as geothermal or water source heat pumps, use the relatively constant temperature of the earth or ground water as the exchange medium instead of the outside air like an air source heat pump. The biggest benefits of ground source heat pumps are they use up to 50% less electricity than conventional heating or cooling systems and the ground loops can last up to 50 years. GSHPs can also provide hot water for your home. A nother option is an air-to-water heat pump (AWHP). Single-family AWHPs are a new offering in the United States. It can be difficult to find a contractor experienced with air-to-water heat pumps, and expensive to install the equipment. Instead of ductwork, AWHPs use pipes to deliver conditioned water. In this case, energy is delivered by the water in pipes instead of by air in ductwork. One of the benefits of this technology is the use of thermal energy storage, or the ability for water to store energy. This allows air-to-water heat pumps to supply hot water to the home.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
BUYING A HEAT PUMP
How Much Will It Cost? The installed cost of a heat pump will
depend on many factors such as whether there’s need for ductwork modifications, electrical upgrades, and complexity of the installation. A single room solution may only be a couple thousand dollars while an entire home solution will be more expensive. A major driver of heat pump equipment cost is the compressor, or the “engine” of the heat pump. Note that all mini-split heat pumps have variable-speed compressors. Ultimately, you will need to discuss various options with your contractor that may present higher or lower installed costs and varying levels of performance.
Compressor Type Description
Installed Cost
Performance
Heat pump only runs at 100% capacity (it’s either on or off) and is limited to heat at moderate temperatures.
Single-Stage
$
Heat pump has two distinct stages of heating and cooling. Typically, high capacity of 100% and low capacity of 70%.
Two-Stage
$$
Heat pump uses an inverter motor to allow for full range of operation. This operates like a car’s accelerator in that the heat pump finds the right speed to run most efficiently.
Variable-Speed
$$$
Cold Climate, Variable-Speed
Heat pump is capable of maintaining high heating efficiency and capacity at very cold temperatures.
$$$$
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
Weatherizing makes a big difference in how much heating and cooling your home needs. Making improvements to your home’s efficiency by adding insulation, air sealing, and other weatherization steps can help your heat pump work better and help avoid the risk of increased energy bills. An energy assessment performed by a FOCUS ON ENERGY® Trade Ally, can earn you more rebates for improvements. Learn more and discover available rebates at focusonenergy.com/residential.
How Do I Buy A Heat Pump? Now that you’ve learned about air-source heat pumps, what they are, and how they can save energy, it’s time to go shopping! There are four key steps when shopping for a heat pump:
Don’t wait until your current equipment fails to research your heat pump options. All too often equipment fails when you need it most, on the coldest or hottest day of the year. If this happens, you may not be able to find the right contractor or the best equipment for your home and end up with a basic replacement of what you already have. Here are some signs that it’s time to start planning for an upgrade: Your heating and cooling equipment is unreliable, inefficient, or over 15 years old. You’ve noticed excessive blower noises, or sporadic pops, bangs, or rattles from your furnace. Your energy bills have gone up.
Your home is cold and uncomfortable. You’re planning a home renovation.
Also, if you’re considering installing a new central air conditioner or replacing an old one, why not go with a heat pump instead? It can provide you with both heating and cooling for a small additional cost.
Reach out to quality contractors you may have used in the past or ask friends and family who they trust. If you don’t know any, find a Focus on Energy Trade Ally to guide you through the process and help you apply for rebates. Make sure the contractors have a good reputation and track record. If a contractor is hesitant or won’t quote a heat pump, it may be best to get a quote from another contractor.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
Most contractors provide a free quote, make sure to ask each contractor for one. When you’re reviewing quotes, don’t rely on price alone since the quality of the design and installation matter just as much. If you’re replacing the heating throughout your entire home, make sure the contractor performs load calculations. For mini-splits serving multiple areas in your home, it’s important heating loads are calculated correctly so the indoor units are sized for the room they’re serving. When it comes to heat pumps, bigger is not better. Heat pumps that are “too big” can create home comfort issues such as being cold and clammy in the summer and heating unevenly in the winter. What are load calculations and why are they important? Load calculations are done by measuring the rooms and windows (including type and direction) and listing insulation values in attics, walls, and basements. The calculations determine the amount of heating and cooling needed to keep your home comfortable. These calculations are sometimes called a “Manual J.” After you’ve received your quotes, make sure to compare heat pump specifications, efficiency levels, warranties, size, parts and labor. Also be sure to check if your quotes include any improvements to the existing duct system such as adding ducts, duct sealing, or adding insulation. Quotes with equipment model numbers and itemized parts and services will make it easier to compare. Remember, the lowest bid isn’t always going to be the best bid. Here are some questions and tips to have on hand to make sure your contractor will correctly design and install your system. For a robust list of questions and considerations, see our FAQ section .
Contractor Knowledge/Experience Considerations Do you know about available rebates and tax credits, and will you help me apply for them? Will you provide training for me on how to properly use and maintain the system? Equipment Considerations Am I likely to save money on my heating costs and how much might I save? Will you do a heating load calculation? Are you familiar with the Northeast Energy Efficiency
Older homes switching from a fossil fuel furnace may need to upgrade their electric service panel to accommodate a heat pump. Weatherizing your home is a great step to reduce your home’s overall heating and cooling needs which may allow you to skip the electrical service upgrade. When replacing other appliances in your home, look for the blue ENERGY STAR logo. ENERGY STAR certified appliances use less electricity than noncertified appliances and last longer!
Partnerships (NEEP) cold climate heat pump list? What type of thermostat do you recommend?
• See the section on Controlling Your Heat Pump for more information.
Installation Considerations Where will you mount the outdoor unit(s) and how?
• Make sure you approve of the location of the indoor and outdoor units. • Ensure the outdoor unit is level, on a pad, and elevated above the snow line. • See section on Protecting Your Outdoor Unit for more information.
If exterior “line sets” ( piping ) will be visible, where will they be placed? • Make sure any penetrations are properly sealed. Will I need any electrical service upgrades to accommodate the heat pumps? • If yes, will I need to hire my own electrician?
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
PAYING FOR A HEAT PUMP
You’re ready to purchase your heat pump, now what? Your contractor may offer financing to help make the purchase more affordable. Be sure to take advantage of tax credits, rebates, and incentives available for homeowners. Efficiency ratings determine incentives. While researching heat pump options, keep an eye out for the equipment’s efficiency ratings. These
Some electric utilities offer special rates for space heating. Contact your local electric utility to find out if they offer special rates if you heat your home with electricity.
will be displayed as SEER, HSPF, EER, and COP. SEER2, HSPF2, and EER2 are updated ratings meant to better reflect the efficiency of installed equipment and will eventually replace the older ratings. These ratings can often be confusing. The most important thing to understand is the higher the rating, the more energy efficient the equipment. Also, many rebates and tax credits specify minimum efficiency values a heat pump must meet to be eligible. While lower efficiency ratings may be less expensive up front, a higher rating will save you money and energy over the lifetime of the equipment and help you earn important rebates and tax credits.
FIGURE 6 Energy Efficiency Ratings for Heat Pumps
Cold Climate Coefficient of Performance at 5°F (COP)
Seasonal Energy Efficiency Ratio (SEER2)
Heating Season Performance Factor (HSPF2)
Energy Efficiency Ratio (EER2)
Ducted Air Source Heat Pump Ductless Air Source Heat Pump
Look for SEER2 ratings above 15.2
Look for HSPF2 ratings above 8.1
Look for EER2 ratings above 10
Look for ratings above 1.75
Look for SEER2 ratings above 16
Look for HSPF2 ratings above 9.5
Look for EER2 ratings above 9
Look for ratings above 1.75
Focus on Energy. Focus on Energy offers a wide variety of rebates to support energy efficiency upgrades for Wisconsinites. Those rebates can help you save energy and money. Learn about all the different rebates Focus offers at focusonenergy.com/residential . Visit the Heating and Cooling page to view the different efficiency ratings required for rebates. Home Energy Efficiency Tax Credits & Federal Rebates. As part of the Inflation Reduction Act, consumers may be able to take advantage of tax credits to make their homes more energy efficient. A qualifying heat pump used for space heating may be eligible for tax credits of 30% of installed cost, up to $2,000. You can refer to ENERGY STAR or the IRS Home Energy Credits for more details on the air source heat pump tax credit. More information on rebates offered through federal Home Energy Rebate Programs will be available once the state has received guidance and approval from the Department of Energy. These Home Energy Rebate Programs are expected to be available in summer of .
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
BEST PRACTICES FOR USING & MAINTAINING YOUR HEAT PUMP
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Getting to Know Your Heat Pump There are a few things that make heat pumps different from traditional heating equipment. Heat pumps naturally develop frost on the outdoor unit during operation, so all heat pumps have defrost cycles that occur for a few minutes, every hour or so, when it’s cold outside. The unit may make gurgling sounds and briefly stop heating, but this is normal.
Heat pumps also run longer, and quieter, than their furnace counterparts. The indoor unit is typically very quiet, and the outdoor unit is typically no louder than your refrigerator. Variable speed heat pumps will be quieter than single-stage versions. The increased run times provide additional benefits such as added filtration and reduced temperature differences throughout your home. In general, modern heat pumps maintain a warm output temperature even at below zero outdoor temperatures, but the air coming from the unit may not feel as “hot” as a conventional furnace. Heat pumps are an easy HVAC system to use and maintain since they use the same components for both heating and cooling. Homes with an air conditioner and a furnace have two entirely separate units to provide heating and cooling which are likely using different energy or fuel sources. Like all heating and cooling systems, proper maintenance is key to efficient operation. Operation & Settings Set Your Thermostat to Your Comfort Level. Depending on the outside temperature and heating distribution of your home, you may need to set your heat pump temperature higher or lower to achieve your desired comfort level. Many home owners that are new to heat pumps find that the cooler air temperature coming out of the vents (or indoor units) and the higher air flow speeds may need to adjust the temperature setting to feel comfortable when it’s cold outside. This setting can be 2-3 degrees higher than the old temperature setting.
Set It & Forget It. Best practice is to set your heat pump thermostat to your preferred comfort level and then let it be. It’s designed to maintain a steady temperature, working gradually and efficiently. Avoid large setbacks while you’re out or sleeping. Stick within four degrees of your preferred temperature. It will continue to heat (or cool) at a slow and steady pace, which enhances comfort and saves you money.
Avoid Auto Mode. Use the ‘Heat’ or ‘Cool’ mode on the thermostat or controller rather than ‘Auto’ temperature setting to avoid unnecessary switch overs on cool summer nights or sunny winter days. As the seasons change, simply adjust your system’s controller to meet the desired temperature that feels most comfortable. In spring and summer consider dry mode, if your unit has one, to reduce humidity without adding cooling.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
Maintenance & Care Keep Indoor Vents Clear And Vanes Open & Directed. If you have indoor units mounted on your wall, keep air vanes open to allow air flow freely throughout the unit. Do not put anything within 3-5 feet of your indoor units and vents. Items such as couches, beds, or dressers can block airflow, causing your room to be uncomfortable. If you are trying to heat or cool multiple rooms, be sure to keep doors open between the heat pump and the rooms you’d like warmed or cooled. If you have indoor units, direct vanes down when heating your home and up when cooling to best circulate the air. Maintaining Your Heat Pump. Maintaining your new heat pump system is similar to how you’d maintain your old system. Make sure you check air filters monthly and clean or replace as needed. For mini-split systems, the indoor unit’s air filter can typically be rinsed off in your sink. You’ll want to make sure outdoor units are kept clear of snow, ice, and debris, and ensure the coils are kept clean. Keep shrubs and bushes pruned back at least 18 inches from all sides to allow for proper airflow and easier servicing. It’s a good idea to have your heat pump inspected yearly by a trained service technician. Refer to your owner’s manual for recommended maintenance. Protecting Your Outdoor Units. Air source heat
pumps should be protected from snow falling from the roof and water dripping directly on the fan of outdoor units. An ideal place to install the heat pump’s outdoor unit is where the eave is large enough to extend past the unit. If the eave is small, a small overhang can be constructed to protect the outdoor units, as shown in Figire 7. Mini-split heat pumps can be mounted on the foundation or exterior wall of the home above the average snow depth. This is only recommended as a last option, especially for wood-framed homes. Another option is to place it away from bedrooms while still close to the indoor unit(s) and elevated on a stand. If the planned location of the outdoor unit is near a quiet space like a bedroom, consider a variable speed heat pump which offers quieter operation.
FIGURE 7. PLACEMENT OF YOUR HEAT PUMP’S OUTDOOR UNIT
What About Wind? If an outdoor unit is likely to get strong winds, a wind baffle from the equipment manufacturer is highly recommended to ensure proper operation of the outdoor unit. Outdoor units may benefit from being located under second floor decks, which can provide some shelter from rain, snow, and wind. A ducted ASHP may be sheltered from wind with decorative fencing or by the building itself, however the manufacturer’s recommended clearance from walls and fencing must be followed for proper operation.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
CONTROLLING YOUR HEAT PUMP
More advanced controls are now available that will determine when the heat pump should operate based on your current fuel prices - leaving you with little to worry about. One thing to keep in mind is not all thermostats are able to control a heat pump. Heat pump specific thermostats may be needed to take full advantage of all their features and capabilities. Be sure to work with your contractor to ensure you have the right controls for your heat pump.
The switch over temperature, which is the most common means of controlling a heat pump, may be configured based on comfort, economics, or the thermal balance point. The thermal balance point is the temperature at which the heat pump can no longer meet the heating needs of the home. In an all-electric centrally ducted system, the backup electric resistance heat should be locked out until the outdoor temperature is below the thermal balance point. Below the thermal balance point, the electric heat runs simultaneously with the heat pump to supplement and meet a home’s heating needs. In this scenario, the goal is to use the least amount of electric resistance heat to operate and maximize the heat pump’s economic advantage during the coldest days of the year. If the lock out is not set up properly, electric resistance heat will cycle on more often than needed causing higher electric use and higher bills. Dual-fuel applications of heat pumps pose additional considerations regarding the switchover temperature. Gas furnaces typically can’t run at the same time as the heat pump. The temperature you want the gas furnace to run may be different than the thermal balance point.
FIGURE 8. DUAL-FUEL SYSTEM WITH GAS FURNACE BACKUP HEAT
FIGURE 9. ALL-ELECTRIC SYSTEM WITH ELECTRIC RESISTANCE BACKUP HEAT
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
The economic balance point describes the outdoor air temperature at which operation of the heat pump’s backup heating system would cost the same to run. This will vary greatly based on the fossil fuel type, cost, and the efficiency of the equipment. Typical economic balance points for a natural gas furnace as back up is between 40-50°F while a propane furnace would have an economic balance point closer to 15-20°F. When conducting annual maintenance on your heat pump, talk to your contractor to determine if the switchover point should be changed. To illustrate these balance points according to fuel prices, the Minnesota Air Source Heat Pump Collaborative developed the chart shown in Figure 10. Using A Programmable Thermostat $0.11
Figure 10. Switchover temperature guide for dual-fuel developed for the MN Air Source Heat Pump Collaborative.
ECONOMIC BALANCE POINT FOR DUAL FUEL
The chart below shows how to select the economic switchover temperature of a dual fuel ASHP installation Note: this assumes cold climate product is sized to meet the heating load of the home.
Natural gas rate, $/therm, (furnaces and boilers)
$0.60 $0.65 $0.70 $0.75 $0.80 $0.85 $0.90 $1.00
$1.15
$1.33
$1.50 $2.00 $2.50 $2.75
$0.05
25°
20°
15°
10°
5°
0°
-5°
-10°
-10°
-10°
-10°
-10°
-10°
-10°
$0.06
35°
30°
25°
20°
15°
15°
10°
0°
-10°
-10°
-10°
-10°
-10°
-10°
$0.07
45°
40°
35°
30°
25°
25°
20°
10°
0°
-10°
-10°
-10°
-10°
-10°
$0.08
50°
45°
40°
40°
35°
30°
25°
20°
10°
0°
-10°
-10°
-10°
-10°
$0.09
60°
55°
50°
45°
40°
40°
35°
30°
20°
10°
0°
-10°
-10°
-10°
$0.10
60°
60°
55°
50°
50°
45°
40°
35°
25°
15°
10°
-10°
-10°
-10°
60°
60°
60°
60°
55°
50°
45°
40°
30°
25°
15°
-5°
-10°
-10°
$0.12
60°
60°
60°
60°
60°
55°
50°
45°
35°
30°
20°
0°
-10°
-10°
$0.13
60°
60°
60°
60°
60°
60°
55°
50°
40°
35°
25°
5°
-10°
-10°
$0.14
60°
60°
60°
60°
60°
60°
60°
55°
45°
35°
30°
10°
-5°
-10°
$0.15
60°
60°
60°
60°
60°
60°
60°
60°
50°
40°
35°
15°
0°
-5°
$0.16
60°
60°
60°
60°
60°
60°
60°
60°
55°
45°
40°
20°
5°
0°
$1.22 $1.83 $2.29 $2.52 Propane rate, $/gallon, (furnaces and boilers) $1.37
A programmable thermostat can be used with a heat pump. However, large setbacks like the ones that are preprogrammed when you purchased it are not suggested. It’s best to create a custom schedule based on when you wake up, leave your house, and go to bed. Only decrease the indoor temperature by three or four degrees during these events in the winter. This is most important for homes using all electric heat pumps, but homes with propane and oil can also see significant savings. Make sure you check with your contractor to ensure your thermostat will work with the heat pump. Using A Smart Thermostat
Similar to a programmable thermostat, a smart thermostat can be used with most heat pumps. They can also be a better option for seasonal cabins with an internet connection or where you want easy access to the thermostat without going to another part of the house. When using a smart thermostat with a heat pump, verify it is not automatically using a preprogrammed setback or auto away mode to avoid large temperature setbacks. When leaving for extended periods of time, such as for the winter, be sure the temperature is reduced as much as possible but never below 55°F in the heating season. When getting ready to return, just open the smart thermostat app and turn the heat up to your preferred temperature. By the time you arrive, your home should be nice and comfortable. Only set your thermostat back three or four degrees at night or when leaving the house. Since a heat pump’s output capacity is lower than a traditional furnace, it will run longer than your furnace does. This helps keep temperatures in your home more comfortable. Coordinating Your Heating If You Also Have A Separate Boiler, Resistance Heat, Or Backup Heating System When your new heat pump provides heating and cooling for your main living area, set the existing thermostats to your old heating system back five or six degrees. Then set the new heat pump to your preferred comfort temperature. If the heat pump can’t maintain its set temperature, the boiler or backup heating system will turn on.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
HOW HEAT PUMPS WORK & OTHER TYPES OF HEAT PUMPS
The Science Behind Heat Pumps Heat pumps rely on the refrigeration cycle to heat and cool your home. The refrigeration cycle consists of four key components: a compressor, a condenser, an expansion valve, and an evaporator. Cooling Mode. The first component, the compressor, is the heart of the system because it’s responsible for circulating the refrigerant that moves heat out of your home. When refrigerant reaches the compressor it’s in a gas state and has a low
temperature and low pressure. As the compressor pulls in the refrigerant, it mechanically compresses it to raise the refrigerant’s pressure and temperature. It’s important for the refrigerant to be at a higher temperature than the surrounding air because it helps with the heat transfer process – heat energy naturally wants to move to areas with lower temperatures and less pressure. The high-temperature refrigerant then moves into the condenser, where its heat is rejected into the surrounding area (the outdoor air). If you’ve ever felt warm air coming from the bottom of your refrigerator, this is your condenser transferring warm air out of the fridge. When the refrigerant leaves the condenser, it changes into a liquid state but remains at a high pressure. It then enters the expansion valve, where the refrigerant’s pressure is lowered before it moves into the last step of the refrigeration cycle; the evaporator. The evaporator consists of an evaporator coil, which is what the low-temperature liquid refrigerant flows through, and a fan. The fan blows warm air from inside your home across the evaporator coil, where the air’s heat energy is absorbed by the cooler liquid refrigerant. The resulting cool air is then pushed back into your home. The process of absorbing heat energy has caused the liquid refrigerant to warm up, and it evaporates back into gas form. The refrigeration cycle is now complete, and the gas refrigerant moves onto the compressor to begin the cycle again. Heating Mode. When you hear the term refrigeration cycle, you likely think of your refrigerator, and that it makes things cooler. So how does a heat pump, which relies on the refrigeration cycle, provide heating too? Heat pumps are equipped with a unique feature called a reversing valve. A reversing valve allows a heat pump to reverse the refrigeration cycle, pulling heat from outside to heat your home during the colder months. Even though it may be cold outside, there is still heat energy in the outside air. A heat pump can absorb that energy and use it to heat your home. Because heat pumps transfer heat rather than producing new heat, they are 2-4 times more efficient than other heating system options.
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
Other Types of Heat Pumps Heat pumps can extract heat from more than just the air to provide heating and cooling to a home. Air source heat pumps extract heat from the surrounding air to provide warm or cool air for a home. Heat pumps can also extract heat from the air to heat water stored in a tank. These are commonly called air-to-water heat pumps. Heat pumps can also extract heat from the ground or water to provide heat. These are commonly called ground source, or geothermal, heat pumps. Ground Source Heat Pumps. Ground source heat pumps, also known as geothermal or water source, use the relatively constant temperature of the earth or ground water as the exchange medium instead of the outside air like an air source heat pump. A ground source system is ideal for: • New homes. • Homes with large lot size for ground loops or wells. • Homes with existing ductwork where modifications can be made. • Small duplexes and triplexes where multiple units can share a single well. • Introducing central air conditioning. • Replacing a heating system for low temperature in-floor heat. • Replacing a central air conditioner and/or furnace. • Reducing reliance on propane or fuel oil. Even though we experience seasonal temperature extremes in the Midwest—from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth’s surface the ground remains at a relatively constant temperature. Since the earth absorbs heat energy from the sun, ground temperatures range from 45°F-75°F. Much like your basement the ground temperature is warmer than the air outside during winter and cooler than the air outside in summer. The ground source heat pump takes advantage of these stable temperatures to be highly efficient and exchanges heat with the earth through a ground heat exchanger. The biggest benefits of ground source heat pumps is they use up to 50% less electricity than conventional heating or cooling systems and the ground loops can last up to 50 years. According to the Environmental Protection Agency (EPA), geothermal heat pumps can reduce energy consumption—and corresponding emissions—up to 44% compared with air source heat pumps and up to 72% compared with electric resistance heating with standard air-conditioning equipment. Ground source heat pumps also improve humidity control by maintaining about 50% relative indoor humidity year-round, making them very effective in humid areas.
FIGURE 11: GROUND SOURCE – CLOSED LOOP
FIGURE 12: GROUND SOURCE – OPEN LOOP
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
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