If you live in Canada, or in most parts of the U.S., you have thought about your home heating system, or at least used it, at some time. There are many different ways to heat a home, one of which is a “heat pump”. If you’re like most of us, you’ve heard of a heat pump, but really have no idea how it works. It’s really just another method of heating your home. A heat pump can not only help your house stay warm in the winter, but it can also keep your house cool in the summer. And it does all these things very economically. In cold weather, it actually manages to pull warm air from outside and transfer it to the inside of your home.
Unfortunately, because temperatures in Canada tend to drop pretty low in the winter, a heat pump likely won’t work for us all year long, meaning we would likely need to have some form of supplementary heat. However, it can still help keep your heating and cooling costs down through much of the year.
What is a heat pump?
There are three types of heat pumps available: air-source, ground-source (also known as geo-thermal), and water-source. The ground and water source types both require quite an extensive amount of coils running beneath the ground or through the water.
In Canada, the most common type of heat pump used is the air-source variety. Basically, a heat pump absorbs heat from one area (outside) and transfers it to another area (inside your house). It operates on the same principle as a refrigerator. Refrigerators extract the warm air from inside the unit and expel it into your kitchen. In your home, a heat pump removes heat from the cold outside air and transfers it into your house. An added bonus is that this process can be reversed in the summertime; the hot air will be extracted from your house and transferred outside, leaving your house nice and cool.
How does it work?
Even though it may be hard to believe, all matter contains heat, even when it’s cold out. A heat pump finds and extracts that heat, and transfers it to where it’s needed (inside your house). Unlike a furnace, it doesn’t need to burn fuel to create heat. A small amount of electricity is used to power the system.
One very important bit of information with regard to heat pumps is that they can produce a great deal of heat when the temperature outside is above 4 degrees Celsius. Once it drops below that, both the efficiency and output capacity suffer. Because of this, most heat pumps in Canada are installed together with a secondary heat source, such as a natural gas forced air furnace. This type of system automatically switches to gas heat when the temperature reaches or falls below freezing.
According to How Stuff Works heat naturally flows downhill. This means that it tends to move from a location with a high temperature to a location with a lower temperature. This is a fairly simple concept. Heat pumps use a relatively small amount of energy to reverse that process. They draw heat out of a lower-temperature area and pump it into a higher-temperature area. Thus, heat is being transferred from a heat source, such as the outdoor air, and into a heat receptacle, such as your home.
Heat pumps used in residential properties are usually what’s called “split systems.” They have an outdoor component, as well as an indoor component, connected through the wall.
A heat pump uses an outdoor fan to take warm air from outside, and pump it through two sets of refrigerant-filled coils, like those in your fridge. It’s then pumped, using an indoor fan, throughout your house.
One advantage of a heat pump over other types of heating systems, is that if you also want air conditioning in the hotter weather, you don’t have to install two separate systems. Heat pumps can heat and cool your home. They’re also very efficient, as they don’t use fuel to create heat, but simply transfer heat from one area to another, using very little energy.
Supplementary heat is sometimes required in areas where the temperature drops below a certain point. Natural Resources Canada has a great explanation of the thermal balance point at which supplementary heat will kick in.
What should you do when something goes wrong?
Heat pumps are fairly high tech machines, involving high voltage electrical circuits, lots of moving machinery, and high pressure refrigerant. It can be very dangerous for an untrained person to attempt installation or repairs, so be sure you contact only a qualified technician to perform any heat pump service.
- Noise: Heat pumps shouldn’t be noisy. If there is noise coming from your heat pump, it could be due to loose fan belts, nuts, or bolts.
- No heat: If there is no heat coming from the heat registers, first check your thermostat. Make sure it’s on “heat,” and set it 2 to 3 degrees above the temperature in the room. Also, check the power supply. If a circuit breaker has tripped, try resetting it. Or check for an on/off switch on the furnace to be sure it’s turned on.
- Ice or frost on the outdoor unit: There could be a problem with the defrost mode, or it could be that the unit is low on refrigerant.
- Steam is coming off the outdoor unit: Don’t worry. This is normal. Heat pumps have a defrost cycle that comes on regularly to remove any built up frost. As this warms up the outdoor coils, naturally you’ll see steam coming off of the unit. This shouldn’t last more than 15 minutes at a time.
How Stuff Works gives you a list of things to watch for:
- If the unit isn’t working, try resetting its motor.
- Check the pump ignition system for problems, and make sure you don’t have a tripped circuit breaker or blown fuse.
- Check the thermostat to make sure it’s working properly.
- Change the filter if it’s dirty, and make sure there are no airflow blockages.
- If the air ducts are making noise when they expand and contract, you could try putting a dent in the side of the duct to make the surface more rigid.
- Rattles may be fixed by fastening loose parts, and if you hear squeaks inside the unit, you may need to replace or adjust the fan belt connecting the motor and the fan.
- A grinding noise may indicate that the bearings on the motor are worn out, which will require the help of a professional to fix.
They warn that if you aren’t mechanically inclined, you probably shouldn’t attempt to do this kind of repair work. The fact that heat pumps can contain hazardous materials is another good reason to let a professional handle it, or at least, give you some assistance. A chemical leak is serious business, and injuries can easily occur when dealing with a broken device.
What can you do to maintain your heat pump?
The first thing you should do is to change the filter regularly. The filter should be changed from once a month to every three months, depending on how often you use it.
Next, have the heat pump inspected. You should have a qualified technician perform an inspection regularly. When the unit is installed, the technician can tell you how often this should be done, but a good rule of thumb is once a year. The technician should:
- Check refrigerant levels, and top them up as necessary.
- Ensure proper air flow. Plants growing near the unit, or any other debris, may have to be removed.
- Check the thermostat to make sure it is still operating properly.
- Replace filters and clean/lubricate other components.
- Check for unusual noises or rattles. This could involve replacing/adjusting belts, bearings, etc. Try to isolate the location of the noise, such as whether it is originating in the air ducts or the actual heat pump unit.
- Check the piping insulation for deterioration.
- Check for proper operation of the compressor and reversing valve.
Natural Resources Canada says that the best time to service your unit is at the end of the cooling season, prior to the start of the next heating season.
What is the life expectancy?
Most experts say that a good quality heat pump should last from 15 to 20 years. Geo-thermal units can last even longer. The main factor for all heat pumps, especially those located above ground, is proper maintenance. Blockages can impede the pump from being able to properly expel heat, for example, so make sure there are no plants growing near it and chip off any ice that forms on the outdoor coil. You’ll also want to regularly change its air filters, keep the coils clean and tidy, and clean the fins on the outside of the unit to ensure it functions as it was designed to. If you’re getting your system serviced annually, modern heat pump systems can last 20 years or more.
What will your home insurance company want to know?
Home insurance companies will want to know what type of heating system your home has, the type of fuel, and the age of the unit. Once a heat pump is nearing its life expectancy, there may be a concern that it stops working, or works less efficiently. If this happens in the middle of a Canadian winter, it could cause the water pipes in your home to freeze and burst. The amount of damage caused by burst pipes can be substantial. It’s in everybody’s best interest to make sure your heating system is in top operating condition at all times. If you have any other questions, you can always contact Square One at 1.855.331.6933 for more information.
Other commonly asked questions
Is a heat pump better than an air conditioner? Whether or not an air conditioner or heat pump is better suited to your home will depend largely on the appliances already available on the property. The biggest advantage for a heat pump is that they’re built to both cool things down in the summer and raise the temperature come winter. But, if your house already has a built-in furnace, electric baseboard heaters or other devices in good working order, then it’s probably not worth splurging on another expensive machine that does more than you need.Air conditioners, meanwhile, are only used for cooling. They are less expensive to purchase and install than a heat pump, however, and cost less on average to run overall. Thus, an air conditioner is an option well worth exploring if all you need is something to chill your house during summer’s sweltering heat.
- How big of a heat pump do I need for my house? An easy way to estimate how much power you need in a heat pump is to go by the overall size of the property you want to install it in using a 600-650 square foot per ton ratio. If you live in a 2,000-square foot home, for example, you can simply divide that number by 650 for a result of 3.07, indicating that a 3-ton heat pump should be more than enough to keep your home temperate year-round.