RSSHeating and cooling
What is heating and cooling?
Each day, millions of Canadians start their days by turning up their furnaces as they trek down the hall to have a hot shower. These two habitual events happen quickly and often without a second thought. Within these passing moments, however, these people are harnessing energy resources and activating the heating and cooling system.
We use the terms heating and cooling to describe our ability to control the temperature of the air and water in our home. This includes heating water for washing clothing, dishes, the property and ourselves as well as keeping the heat levels in our home at a comfortable level.
Water heating
Water heating involves consumption of energy to heat water for domestic purposes such as laundry, dishwashing, cleaning and bathing. In an average Canadian home, water heating is the second largest user of energy, after space heating, consuming approximately 14 per cent of the total household energy.
Common systems in Canada
Various types of water heaters are available and widely used in Canada. Storage water tanks are the most popular in Canada, but these systems are used along with tankless, integrated space heat pump, solar and heat recovery water heating systems.
- Storage tank water heaters heat and store water in a single tank. The energy source can be natural gas, electricity or fuel oil. They are the most common kind of water heater in Canada.
- Tankless water heaters consist of an electric element or gas burner which heats water on demand. Usually situated close to where the water will be used, tankless water heaters generally have lower capacity that storage tank water heaters.
- Integrated space/water heating systems employ a single burner, boiler and vent to heat water for both space heating and hot water uses. The hot water circulates through a heat exchanger and the resulting hot air is blown through the house as with a conventional heating system.
- Heat pump water heaters transfer heat from the air, or from the earth or groundwater, to water in a tank. They do not generate heat, and are not effective at temperatures lower than 8°C.
- Solar water heaters use energy from the sun to heat water in a solar collector. The water is then transferred to a storage tank, where it is either heated further by a conventional storage tank heater or passed through a heat exchanger to heat water for home use.
- Heat recovery water pre-heaters are heat exchangers that recover heat from used hot water as it goes down the drain. The recovered energy is used to preheat water in a conventional storage tank heater.
Energy sources used
For Canada as a whole, natural gas supplies 58 per cent of the energy used in water heating, with electricity supplying 37 per cent. Heating oil only accounts for four per cent of the energy used.
The popularity of these sources, however, is not universal across the country. According to Natural Resource’s Canada’s Survey of Household Energy Use, households in Quebec and the Maritimes are more likely to use electricity to heat water than households in the provinces west of Quebec, which favour natural gas. And the Maritime Provinces mark the only region where heating oil is used in a significant number of households to heat their water.
New technologies
There are several new technologies that improve energy efficiency in water heating systems, including high efficiency water heaters and electronic ignitions.
Higher efficiency water heaters have better insulation and flue controls to prevent heat loss, more efficient heat exchangers, and special valves that prevent hot water from entering the piping system when it isn’t needed.
Electronic ignition on gas water heaters saves natural gas by eliminating pilot lights.
Space heating
Of all of the activities in the home that require energy, space heating uses the most. Space heating, which involves the consumption of energy to heat your home, consumes about 33 per cent of the energy used in Canadian households. Because of Canada’s constantly shifting climate, we rely on space heating for a substantial part of the year.
Common systems in Canada
The popularity of certain heating systems varies from one region to the next in Canada. Electric baseboards, for example, are more popular in Eastern Canada then they are in the western provinces with approximately 60 per cent of the population of Quebec and 30 per cent of Atlantic Canada using them as the main method of household heating.
The regional differences between heating methods are not the only variations between the systems. Each type of heating system consumes energy and heats the air in different ways.
Furnaces
Forced air furnaces consist of a burner, heat exchanger, fan, ductwork and chimney. The burner ignites the fuel creating combustion gases that pass across the heat exchanger and up the chimney. The fan forces cool air across the heat exchanger and throughout the house via the ductwork. In natural gas and oil-fired furnaces, the combustion system and circulating system are completely separate. With electric forced air systems, the air is heated directly by electric elements and forced through the ductwork by the fan.
Hydronic systems, also known as hot-water furnaces, are similar to forced air systems except water, instead of air, is heated and circulated throughout the house via pipes and heat from the water is exchanged via baseboard radiators in each room. Energy is supplied by natural gas, fuel oil or electricity. Some hydronic systems function as both space and water heaters.
Electric baseboards
Baseboard heaters use a process called electric resistance to heat a room. Inside each baseboard, there are electric cables that heats any air passing through it. As the air is heated, the warm air rises out the top of the heater and colder air is pulled into the baseboard from the bottom. This cycle continues until the air entering the heater reaches the temperature specified by the thermostat.
Heating Stoves
Heating stoves and fireplaces can be fuelled by natural gas, wood or pellets. The energy source is burned, which warms the surrounding air. All pellets are made of natural biomass materials, that is, products of commonly grown plants and trees. In most designs, a fan delivers this heated air to the home by blowing air through heat exchangers in the stove and out into the home. Advanced sealing techniques and heat exchangers have increased the energy efficiency of these heaters.
Heat pumps
Air source heat pumps move heat from one place to another; therefore, they can be used to either heat or cool a house. Heat pumps work by repeatedly circulating a refrigerant through a cycle of evaporation, compression, condensation and expansion. At the start of the evaporation cycle, the refrigerant is a low-pressure, low temperature liquid that passes through a heat exchanger where it absorbs heat from outdoor air and vapourizes.
The vapour is then compressed, causing its volume to decrease and its temperature to increase, after which it passes through another heat exchanger where it gives off heat to indoor air and condenses into a liquid. The liquid then passes through an expansion valve which reduces its pressure and the cycle begins again. To cool the house, the flow is reversed and heat is absorbed from inside air and given off to outside air.
Other
Ground source heat pumps, or earth energy systems, work the same way as air source heat pumps except instead of absorbing heat from air, they absorb it from the earth. The refrigerant is pumped through underground piping system where it absorbs heat in the heating cycle and gives off heat in the cooling cycle.
Energy sources used
In Canada, more households use natural gas to run their main heating system than any other energy source. Natural gas supplies 55 per cent of the energy used to heat homes in Canada. Other sources used by households for their main heating system were electricity, used by 19 per cent of households; heating oil, used by 11 per cent; and wood, used by 13 per cent.
Regional differences can also be noticed in the energy sources that are used in Canada. Natural gas is most often the main energy source for space heating in British Columbia, Alberta, Saskatchewan, Manitoba and Ontario. Electricity is popular in Quebec and the Maritime provinces, and heating oil is used mainly in the Atlantic provinces.
These differences can be largely based on source availability, price and supply and demand trends that change from one region to the next. Energy availability is also based on provincial energy policies; for example, many provinces supply electricity at a low price due to policies that mandate a regulated electricity price that is not based on market or marginal cost prices. Other provinces, such as Quebec and Manitoba, have made the policy choice to provide residents and businesses a lower rate on hydropower than is seen on the export market.
| Region | Energy Source | Penetration Rate |
| Atlantic | Oil | 39% |
| Electricity | 38% | |
| Quebec | Electricity | 73% |
| Ontario | Natural gas | 68% |
| Prairies | Natural gas | 78% |
| British Columbia | Natural gas | 52% |
Space cooling
Space cooling, which involves the consumption of energy to cool buildings, is becoming increasingly popular in Canada. In the decade between 1993 and 2003, the energy used for cooling residential space more then doubled. Overall though, space cooling only consumes about 0.5 per cent of the energy used in the residential sector. This number has continually grown as more and more people install air cooling systems in their homes.
In 2003, almost 45 per cent of all Canadian households had some form of an air conditioning system. As may be expected, the provices with the warmest summers (Quebec, Ontario and the parairie provinces) have the highest number of installed air cooling systems.
Ontario has the largest rate of air conditioners per household in the country with 75 per cent of all dwellings containing an air cooling system. This province accounts for 60 per cent of all residential air cooling systems in Canada.
Common systems in Canada
All air conditioners are actually heat pumps that only cool indoor spaces and cannot be used for heating. In Canada, air conditioning systems are available as window/room air conditioners, central air conditioners and heat pumps.
Room air conditioners are small units that cool only the rooms in which they are located. Central air conditioners, which are the most common in Canada, are used to cool an entire household.
Air source heat pumps move heat from one place to another; therefore, they can be used to either heat or cool a house. Heat pumps work by repeatedly circulating a refrigerant through a cycle of evaporation, compression, condensation and expansion. At the start of the evaporation cycle, the refrigerant is a low-pressure, low temperature liquid that passes through a heat exchanger where it absorbs heat from indoor air and vapourizes. The vapour is then compressed, causing its volume to decrease and its temperature to increase, after which it passes through another heat exchanger where it gives off heat to outdoor air and condenses into a liquid. The liquid then passes through an expansion valve which reduces its pressure and the cycle begins again. To heat the house, the flow is reversed and heat is absorbed from outside air and given off to inside air.
Ground source heat pumps, or earth energy systems, work the same way as air source heat pumps except instead of giving heat off to outside air, they give it off to the earth. The refrigerant is pumped through underground piping system where it gives off heat in the cooling cycle and absorbs heat in the heating cycle.
Energy sources used
Almost 100 per cent of space cooling is powered by electricity. Overall, space cooling consumes about 0.5 per cent of the energy used in the residential sector.
Regional differences can also be noticed in the energy sources that are used in Canada. Natural gas is most often the main energy source for space heating in British Columbia, Alberta, Saskatchewan, Manitoba and Ontario. Electricity is popular in Quebec and the Maritime provinces, and oil is usually only used in the Atlantic provinces. These differences can be largely based on source availability, price and supply and demand trends that change from one region to the next.
