Heat Pump FAQ

What are air-source heat pumps?

Air-source heat pumps (ASHPs) are appliances that use electricity to provide heating in winter and cooling and dehumidifying in summer. Unlike other heating systems that convert fuel or electricity directly into heat, ASHPs only move heat from one place to another. Heat pumps are not a new technology, they have been has been used in Canada and around the world for decades.

Refrigerators and air conditioners are both common examples of heat pump technology. Ductless ASHPs known as “mini-splits” are common in Europe and Asia, and have become very popular in PEI over the past few years.    

How do air-source heat pumps work?

All ASHPs have three cycles: the heating cycle, the cooling cycle and the defrost cycle.    

During the heating cycle, heat is taken from the outdoor air and transferred indoors through the use of a fluid called a refrigerant that is contained within a closed loop inside the heat pump. The refrigerant absorbs heat from outdoors when it evaporates and is then transported indoors. The heat is released indoors as the refrigerant condenses. The refrigerant is then returned to the oudoor compressor to repeat the process.    

The cooling cycle is the same as the heating cycle, but in reverse, and is used in the summer for cooling. The refrigerant takes heat from the indoor air through evaporation and releases that heat to the outdoor air when it condenses. During the cooling cycle, the heat pump also dehumidifies the indoor air.

The defrost cycle is identical to the cooling cycle except that it is used during the heating season to periodically defrost the outdoor heat coil to help keep the heat pump operating efficiently (a buildup of frost on the outdoor coil reduces the ability of the refrigerant to absorb heat from the outside air).  

The ability of the heat pump to transfer heat from the outside air to the inside air depends on the outdoor temperature. As the temperature outside drops, the ability of the heat pump to transfer heat also drops because of the larger difference in temperature between indoors and outdoors.   

Are there different types of air-source heat pumps?

There are two main types of air-source heat pumps: ductless or “mini-split” systems and ducted systems.

Ducted systems use your home’s existing forced-air ducting to distribute heating and cooling whereas mini-splits do not require a forced-air system.  

Ductless mini-split systems are generally more affordable than ducted systems and are currently the most popular choice of homeowners in PEI because most homes do not have an existing warm air ducting system. 

A reputable HVAC professional or company specializing in heat pump sales and installations can advise you on which system is best suited to your particular needs.   

You may also contact EfficiencyPEI for additional information and advice.   

What are cold climate air-source heat pumps?

Cold climate air-source heat pumps (ccASHPs) can be defined as systems that are designed to operate efficiently for weather conditions as cold as -25°C. More efficient compressors, larger heat exchanger surfaces, improved refrigerant flow and other controls are largely responsible for the improved performance of cold climate systems.   

How are air-source heat pumps rated for efficiency?

The seasonal heating and cooling efficiency of ASHPs are affected by the manufacturer's choice of features and components and the minimum energy performance standards set by Natural Resources Canada (NRCAN) under Canada’s Energy Efficiency Regulations

The most commonly used measure of a heat pump's heating efficiency is called the Heating Seasonal Performance Factor or HSPF. The higher the HSPF, the more efficient the heat pump. The HSPF is the ratio of the total heat output of a heat pump over the entire heating season divided by the total electricity it uses during that time. Air-source heat pumps typically have HSPFs that vary from 6.7 to greater than 10.0 depending on make and model. 

To help ensure you are purchasing the most efficient heat pump that will operate at colder temperatures such as those experienced during PEI winters it is suggested that a minimum HSPF rating of 10 is required. PEI is in climate region 5. If climate region 5 is not specifically stated, then the HSPF rating is probably for climate region 4 (to convert a climate region 4 HSPF rating to a climate region 5 HSPF rating divide by 1.15). 

Remember, when purchasing a an air-source heat pump, it is the HSPF rating that you should be looking for, with “most efficient” cold climate heat pumps having an HSPF rating greater than 10 for climate region 5. These units will bear an ENRGY STAR® “Most Efficient” label.

 

What are ENERGY STAR® rated heat pumps, and how can I identify the most efficient heat pumps using the ENERGY STAR rating system?

ENERGY STAR® is a U.S. Environmental Protection Agency (EPA) voluntary program that helps businesses and individuals improve comfort, save money, and reduce both energy usage and emissions of greenhouse gases (GHGs) through superior energy efficiency.  Canada is an international partner in the U.S. ENERGY STAR® program since 2001.  Typically, an ENERGY STAR® qualified product is in the top 15 to 30 percent of its class for energy performance.    

ENERGY STAR® qualification in Canada is based on the U.S. ENERGY STAR® program and adheres to U.S. minimum performance standards for both ENERGY STAR® and ENERGY STAR® “Most Efficient” products.   

What is the expected service life and warranty of an air-source heat pump?

Most air-source heat pumps have a service life of between 15 and 20 years. The compressor is the critical component of the system. Most heat pumps are covered by a one-year warranty on parts and labour, and an additional five to ten-year warranty on the compressor (for parts only).

Warranties may be invalidated if the ASHP is not installed by certified and licensed installers.

Will my electricity bill go up if I install an air-source heat pump?

That depends. If you install an air-source heat pump for a household that currently uses electric resistance baseboard heating, your electric bill should decrease. This is because an air-source heat pump is more efficient than electric resistance heating because a heat pump moves heat from outdoors to indoors, rather than converting electricity directly into heat.  

However, if you purchase and install an air-source heat pump for a household that currently uses furnace oil, your electric bill should increase, but your oil bill should decrease. This is because fuel oil usage is displaced by the electricity used by the heat pump.    

Predicting savings can be difficult given the many variables that affect your household’s space heating performance. These include the size, layout and insulation levels (including doors and windows) of your home, the occupant understanding and operation of the heat pump, control configurations such as where thermostats are located and what set points are used, and the comfort levels desired by the homeowner.  

Remember, if you install an air-source heat pump, it is advisable that you keep your existing electric resistance or furnace oil space heating system in place as a backup. Even the most efficient heat pumps available today should be viewed as supplemental heating systems only.  

If I currently use furnace oil for space heating, how much can I expect to save over the course of a year by installing an air-source heat pump?

Based on a typical 1,200 ft² bungalow in PEI, Maritime Electric estimates a net annual saving of $768 for a home owner who currently uses furnace oil to heat their home and then installs an air-source heat pump for supplemental heating. See Choosing a Mini-Split Heat Pump for additional details on savings.  

Your actual savings may be more or less than Maritime Electric’s estimated savings depending on the size of your home and the factors mentioned above including building insulation and comfort levels desired.   

* Energy cost per year based on Maritime Electric residential first block energy charge of $0.1437/kWh. 

If I currently use electric resistance baseboards for space heating, how much can I expect to save over the course of a year by installing an air-source heat pump?

Based on the same typical 1,200 ft² bungalow in PEI, Maritime Electric estimates a net annual saving of $1,099 for a home owner who currently uses electric resistance baseboards to heat their home and then installs a cold climate air-source heat pump for supplemental heating.  

See Choosing a Mini-Split Heat Pump for additional details on savings.   

Your actual savings may be more or less than Maritime Electric’s estimated savings depending on the size of your home and the factors mentioned above including building insulation and comfort levels desired. 

* Energy cost per year based on Maritime Electric residential first block energy charge of $0.1437/kWh. 

 

Does my home or business need to be well insulated to benefit from the installation of an air-source heat pump?

Not necessarily. However, if your building is poorly insulated, you may be better off spending your money on upgrading the building envelope first before considering the installation of a heat pump. 

How do I make sure I purchase the correct size heat pump for my home or business?

Among the variables to be considered are whether the heat pump is for a ducted system or will be a mini-split, the extent to which cooling is important, and whether the unit will have a variable speed compressor.  

It is recommended that you speak with a certified heat pump installer to better determine the most appropriate size unit for your particular requirements.   

How many air-source heat pumps will I require to heat my house?

That depends. The most popular choice in PEI is the mini-split air-source heat pump with one head. The head is the unit installed inside your home or business that provides warm or cool air to the interior of your building envelope.

Some mini-split units have two or more indoor heads that run off a single compressor. The compressor is the outdoor component of your air-source heat pump. Generally speaking, mini-split air-source heat pumps with more than one head tend to be somewhat less efficient.    

It is recommended that you discuss the various options with a heat pump sales and installation contractor for the most appropriate information concerning how many heat pumps or heads units you may wish to install.

Do I need 200 amp service for my new heat pump?

In most cases you will not need to upgrade to a 200 amp service if you are only installing one mini-split air-source heat pump. If you plan to install more than one unit, you may need to upgrade to a 200 amp service.

Please be advised that your certified heat pump installer does not have access to your Maritime Electric account. Therefore, should you require upgrading to 200 amp service, you will need to contact Maritime Electric directly to arrange for the upgrade.  

To contact the Maritime Electric Customer Service Department, please call 1-800-670-1012.    

Who installs air-source heat pumps?

One of the most important aspects for ensuring optimal performance and customer satisfaction with a new air-source heat pump is the installation.  

Installations that are done incorrectly, or performed by unqualified installers, may not perform to specification and may invalidate the manufacturer’s warranty.  

There are a number of certified installers in PEI who are licensed to handle refrigerants and work with electrical connections.     

Can I install my new air-source heat pump myself?

Maritime Electric does not recommend you install your new air-source heat pump yourself unless you are licensed and certified to handle refrigerants and work with electrical connections.  

Installations that are done incorrectly, or performed by unqualified installers may not perform to specification and may invalidate the manufacturer’s warranty.    

How is a heat pump installed? How long does it take to install one?

All mini-split air-source heat pumps consist of two main components, the outdoor compressor, and the indoor head. The compressor and head are connected by piping that contains refrigerant, a fluid used to transfer heat from outdoors to indoors, as well as a power connection.  

Generally speaking, a certified installer should be able to install your new air-source heat pump in less than one day.

It is recommended that you discuss the various installation options with your heat pump sales and installation contractor for the most appropriate information regarding this matter.   

What is the best location in my home to install an air-source heat pump?

It is recommended that you discuss the various installation options with your heat pump sales and installation contractor for guidance regarding this matter. 

Can air-source heat pumps be used in commercial buildings?

Yes. Many commercial buildings have adopted air-source heat pumps for heating and cooling needs.  It is recommended that you discuss the various installation options with your heat pump sales and installation contractor for guidance regarding this matter.

If I purchase a mini-split heat pump can I get rid of my existing oil furnace or electric baseboard heaters?

No. Even if you install an ENERGY STAR® "Most Efficient" mini-split heat pump, it is advisable that you keep your existing electric resistance or furnace oil space heating system in place as a backup.

Mini-split heat pumps should be viewed as supplemental heating systems only. 

Will my air-source heat pump shut-off or stop producing viable amounts of heat as the temperature outside drops to -25 °C?

Air-source heat pumps operating efficiencies differ between manufacturers and models, with some units being significantly more efficient, especially at colder temperatures.   

Maritime Electric recommends you consider purchasing the most efficient airsource heat that your budget will allow. To help ensure you install a heat pump that will provide heating at colder temperatures you should consider purchasing an ENERGY STAR® rated “Most Efficient” air-source heat pump.

Remember, if you install a mini-split heat pump, it is advisable that you keep your existing electric resistance or furnace oil space heating system in place as a backup. Heat pumps should be viewed as supplemental heating systems only. 

What kinds of maintenance does a heat pump require?

An annual inspection and deep cleaning is recommended to avoid the possibility of mold growth inside the head (the unit that is installed indoors) and to keep your heat pump running at optimal efficiency. The inspection and cleaning will generally include filter cleaning (or replacement) and coil cleaning.

The manufacturer’s instructions that came with your heat pump will outline the most appropriate maintenance and cleaning schedule for your unit. Your contractor may also provide maintenance services, including an annual visit for cleaning and testing.  

Remember, only certified installers licensed to handle refrigerants and work with electrical connections will be able to perform some of the more difficult maintenance activities such as checking the refrigerant level and making system adjustments.   

Where do I purchase air-source heat pumps in Prince Edward Island?

Maritime Electric does not recommend any specific air-source heat pump provider. For additional information on heat pump sales and installation contractors in Prince Edward Island you can visit your yellow pages under heating and cooling or search the internet for a vendor near you.    

You may also contact the EfficiencyPEI for additional information and advice concerning this matter.   

Are there any government grants or rebates for air-source heat pumps in Prince Edward Island?

The PEI Energy Efficiency Program administered by EfficiencyPEI is an incentive program for residential property owners who wish to upgrade the energy efficiency of their properties.  

It consists of a grant program to assist with the implementation of eligible upgrades.  

For additional information on grants and services available please contact EfficiencyPEI.    

Does Maritime Electric offer any incentives towards the purchase and installation of air-source heat pumps?

Maritime Electric does not offer any grants or rebates towards the purchase of air-source heat pumps.   

Will my use of an air-source heat pump help the environment by lowering greenhouse gas (GHG) emissions and other pollutants?

Yes, air-source heat pumps are cleaner than burning fossil fuels even if they’re powered by electricity generated using oil or natural gas. That’s because they’re so efficient that less oil or natural gas is needed to generate the electricity required to operate the heat pump than you’d need to operate your oil furnace or electric baseboards in your home to make the same amount of heat. In PEI approximately 25% of our electricity is generated by wind.

The other environmental concern is that heat pumps are much like refrigerators, which means they contain chemical refrigerants that are used to transfer heat in or out of your home. Some of these refrigerants contribute to depletion the ozone layer. There are models and manufacturers that use less harmful refrigerants. Choose a heat pump that minimizes pollution and maximizes energy efficiency.    

Are air-source heat pumps safe when operating?

Air-source heat pumps are safe when operating. The Canadian Standards Association (CSA) currently verifies all heat pumps for electrical safety. A performance standard specifies tests and test conditions at which heat pump heating and cooling capacities and efficiency are determined. The performance testing standards for air-source heat pumps are CSA C273.3 and C656.  CSA has also published an installation standard for add-on air-source heat pumps (CSA C273.5-1980). 

Will my new air-source heat pump make noise and disturb my neighbours?

Air-source heat pumps are not silent in their operation, either inside the home or out. A typical mini-split heat pump will have indoor noise rating between 21 to 43 dB and outdoor noise rating around 50 db.  At these sound levels the heat pump is audible at low levels both indoors and out. The sound a heat pump makes can be compared to a window air conditioner.  It is a whooshing sound associated with the unit’s fans and compressor.    

One way to reduce the noise from a heat pump is to install a unit that has a variable speed compressor. Most of the time heat pumps with variable speed compressors will operate at less than full output, with an associated reduction in noise from the compressor and fans.  

Manufacturer’s specification sheets will show the indoor and outdoor noise levels for any unit you may be considering installing in your home or business.    

Will my new heat pump cause voltage fluctuations?

With the “cycling” of heat pumps there is the potential for voltage fluctuations similar to those occasionally observed when an oil furnace starts.    

Maritime Electric recommends that you consult with your heat pump contractor to ensure that the system you purchase has “soft start” capability as a way to reduce any potential voltage fluctuations. The better quality units usually have this feature.   

What if I use wood or wood pellets? Is this still worth looking into?

Cord wood and wood pellets are reported as cost competitive with heat pumps, so if you’ve already largely switched from fossil fuels to wood the cost savings of installing a heat pump will be smaller. Here your decision will be more influenced by other considerations such as cooling in summer.  

Heat pumps have two other advantages over wood and pellet stoves – convenience (no loading necessary) and local air pollution (even the most efficient biomass stoves emit particulates, though substantially less than older stoves and fireplaces).