Air-to-Air Heat Pumps
Ground Source Heat Pumps
If you are exploring the heating and cooling options for a new or existing house or if you are looking for ways to reduce your energy costs, consider purchasing an energy-efficient heat pump. A heat pump can provide year-round climate control for your home by supplying heat to it in the winter and cooling in the summer. Some types can also provide supplementary hot water heating.
A heat pump works just like an air conditioner but also provides space heating during the heating season. The heat pump is best used in conjunction with your central furnace to provide the required space heating more economically. Therefore, choosing a heat pump not only provides the desired space cooling, it is also an effective way to reduce heating energy costs. In addition, choosing a high-efficiency heat pump over a lower efficiency heat pump can save you even more money and energy.
Selecting an energy-efficient heat pump is now made easy. EnerGuide has developed a rating system for heating and cooling equipment called the EnerGuide Rating System. The rating for the cooling mode, found on the back of manufacturer's brochures, is designed to help you make an informed choice when buying a heat pump. We recommend that you refer to the Heating Seasonal Performance Factor (HSPF) for the heating mode found in manufacturer's brochure. So read on to find out what the information on the EnerGuide Rating for heat pumps tells you so that you can make an informed decision when purchasing a heat pump.
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What is the ENERGY STAR air-to-air heat pump, and where do I find it?
Manufacturers or retailers volunteer to place the ENERGY STAR symbol on those models for which they have demonstrated they meet or exceed the ENERGY STAR energy-efficiency criteria. Today, most leading manufacturers of home heating and cooling equipment are producing high-efficiency systems that qualify for the ENERGY STAR symbol.
Usually, you can locate the ENERGY STAR symbol on the back of the manufacturers brochures, beside the EnerGuide rating box. Use the EnerGuide rating to determine the SEER and HSPF ratings and locate the ENERGY STAR symbol to ensure you have the most efficient product available.
When looking for a high efficiency air-to-air heat pump, also consider an ENERGY STAR programmable thermostat. These thermostats have four daily settings, weekend/day settings, and other energy comfort features. They automatically adjust the temperature to the comfort setting you choose: lowers it while you are away at work, raises it for when you are at home, and provides flexibility for weekend use.
Ground-Source Heat Pumps: Heating and Cooling Your Home from the Ground Up
Does it make a difference for homeowners?
"Knowing what I know now as far as cost savings, I would consider the ground-source heat pump again, especially for a family with two small children," commented Mr. Barnes. According to Mr. Gallant, "the geothermal units are fantastic and very economical too."
Environmentally friendly and they save money, too!
Shadow Ridge Estates in Greely, Ontario, is an excellent example of why choosing geothermal heating and cooling systems is a major plus for both builders and homebuyers!
"I originally was drawn to this system because it is so energy-efficient and environmentally friendly," Don Cardill, owner of Donwel Construction, explained. Mr. Cardill quickly found out that offering a ground-source heat pump that heats a home in the winter and acts as an air-conditioning unit in the summer is a great selling feature for new home buyers. "We can offer our customers something nobody else does - and it's the same price," he said.
How they work
Geothermal heating and cooling systems (also called earth energy systems, ground-source heat pumps or GeoExchange SM systems) are heat pumps that collect and transfer heat from the earth through a series of fluid-filled, buried pipes running to a building, where the heat is then concentrated for inside use. Ground-source heat pumps do not create heat through combustion - they simply move heat from one place to another.
Heat pumps also operate in reverse to cool a home by transferring the heat out of the house, where the cooler ground absorbs the excess heat. The system is appealing because a single system can be used for both heating and cooling, thus eliminating the need for separate furnace and air-conditioning systems.
Ground-source heat pumps offer a different kind of heating. Unlike conventional forced-air furnaces, geothermal units offer a steady heat. "There is no "blast" of hot air- it provides a constant heat," said Mr. Proudfoot, a satisfied customer and three-year home-owner in the community "But what we really like is that it's a clean heat - there's no residue or dust around the house like there was with a forced-air heating system in our home in the city."
Geothermal units are also extremely efficient in cooling homes. "I'll put it up against any external air conditioner - they are very efficient," said Bill Barnes, a 10-year resident of Shadow Ridge Estates. "We can cool the main floor of our house down in just one hour. We couldn't do that with our old system."
"I really like the fact that there's no big noisy implement outside my house to provide air conditioning. This is part of the furnace," said Mr. Gallant another homeowner. "The fact that the air conditioning came with our house was a definite bonus," said Mr. Proudfoot.
At Shadow Ridge Estates, ground-source heat pumps in some homes also provide:
° radiant floor heating
° heating tubes in laneways to melt snow in the winter
° hot water for outside hot tubs and
° energy to heat hot water.
Cost Savings for Homeowners
There are significant cost savings in the monthly hydro bills of people with ground-source heat pumps. A 2, 000 sq. ft. (185. 8 m 2) home built above R-2000 standards at Shadow Ridge Estates had an air conditioning cost of less than $50 for the whole cooling season and a heating cost of less than $300 for the entire winter!
Yearly maintenance of ground-source heat pumps is simple and straightforward. "They come in and do an acid wash to clean the pipes and make sure there's no buildup of mineral sediments," commented one homeowner, Barry Proudfoot. Maintaining the system has also been positive for Bill Barnes. "We only had to replace our well pump once after 10 years of operation," he commented.
The soil at Shadow Ridge Estates is a sand and gravel mix that is ideal for a ground-source heat pump system. Homes in the first five phases of the development have an open-loop design for their ground-source heat pumps. Each unit is connected to its own well and washes water through to a 25 ft. (7. 6 m) deep hole on each property. There is about 40 ft. (12. 2 m) of 1 1/ 4 inch (3. 2 cm) piping from the home to the well for the open loop system.
The sixth phase will offer a closed-loop system that runs off a communal water and septic/ peat bed system. This change was inspired by recent changes to environmental regulations requiring a home to have 1 hectare of land for a septic tank. Mr. Cardill's solution means that he can have smaller lots and still offer customers an environmentally friendly and efficient heating and cooling system.
Donwel Construction uses 200 ft. (61 m) of piping per ton of furnace. In the closed loop system the pipes are buried at 25 ft. (7. 6 m) or at the water table, whichever is lower. Homes in Shadow Ridge Estates have both forced-air and hydronic heating systems. All homes have forced-air units, and the heat pumps in homes with radiant floor heating have hydronic capability. All units are rated as high-efficiency heat pumps.
The size of the heat pump is measured by tonnage* according to the size of the home. For example, a 5 ton unit in a 3, 600 sq. ft. (334. 5 m 2 ) home provides 62, 600 Btus of heating and 54, 700 Btus of cooling. A 2 ton unit in a 1, 500 sq. ft. (139. 4 m 2 ) home provides 22, 000 Btus of heating and 24, 000 Btus of cooling.
Source: Natural Resources Canada (NRCan) - Office of Energy Efficiency