Heating without fossil fuels

As humans continue to use fossil fuels, carbon dioxide will continue to accumulate in the earth’s atmosphere, intensifying the impacts of climate change. Since the beginning of the industrial revolution atmospheric CO2 levels have increased by 50 percent (from 280 ppm to 420 ppm today). For the sake of a livable future world, we must reduce our use of fossil fuels as quickly as possible. When my church, Meadowlands Fellowship Christian Reformed Church in Ancaster, built its new facility in 2005, the decision was made to install a geothermal (or ground source) heating and cooling system; ours was the first church in Ontario to go fully geothermal. The building has no gas supply. At that time, we realized that during the lifetime of the building, fossil fuels would have to be phased out and so we looked for an alternative method to heat and cool the building.

How it works

A geothermal system uses heat pumps similar to those found in refrigerators and air conditions; these pumps remove heat from one area into another. In the case of our church, 12 heat pumps extract heat from a fluid that flows through about 7 km of pipe laid horizontally under our parking lot (hence the term geothermal or heat from the ground); the heat pumps remove heat from the fluid and use it to heat the building using conventional duct work. In the summer, the heat pumps work in reverse, drawing heat out of the building and transferring it into the ground. For every unit of electricity used, approximately four units of heat are supplied to the building; newer units are even more efficient.

How well has this system worked over the past 18 years? Based on calculations using Portfolio Manager (a program developed by the U.S. Department of Energy to calculate energy use per unit area), our facilities use approximately 1/3 of the energy per square foot compared to conventional structures. Our annual utility costs (electricity and water) are approximately $1.00/sq. ft., again about 1/3 that for conventional construction. In terms of maintenance, several compressors in the heat pump units have been replaced, but otherwise only the usual annual check-ups and cleaning of filters is required. All in all, the system has performed well.

Cost and efficiency

What about the initial cost of this system? The cost was obviously more than conventional roof top heating, ventilation and air conditioning (HVAC) units, but most of that extra cost was for the installation of the pipes for the ground portion of the system. Conventional HVAC equipment installed on a roof might be cheaper initially, but they have serious efficiency problems. In the winter the roof is the coldest and the equipment must first be heated up before warm air can be blown into the building. In the summer, the roof is the hottest location and air conditioners have to work harder to pump heat out of the building. I would certainly recommend any churches or schools planning to build new or to replace their furnace or boiler to consider a heat pump system; grants are available to help reduce costs.

There are different types of heat pumps. Instead of horizontal pipes (as we used with our church) deep wells can also be drilled into the ground and pipes placed into them if little land is available (as in the case of a city lot); a 100m deep well can accommodate 200m of pipe (down and back up). Although ground-source (or ground-to-air) heat pumps are more efficient (due to the almost constant temperature of the ground) air-to-air heat pumps are less costly, as no ground loop is required.

Heat pumps at home

What options are available for the average homeowner for eliminating fossil fuels? In recent years, air-to-air heat pumps have been developed that will work almost anywhere in Canada (down to about -30°C). These units are a great replacement for a gas furnace or boiler; they can also be used to provide hot water. If you have a gas furnace or boiler that is still working, start thinking about replacement now, as you need time to do an energy audit, find a qualified contractor and decide what size system you need. As an incentive for switching to greener energy, the Canada Greener Homes Initiative (a Federal program) offers grants up to $5000 as well as up to $600 for an energy audit of your home. In addition, interest-free loans of up to $40,000 are available. Some provinces may have additional grants. Local contractors will have the latest information available for you.

Upgrading your church or home to an energy-efficient heat pump is an excellent way for church communities and individuals to reduce their carbon emissions and at the same time show that you care for God’s creation. You can make a difference!