Heat Pumps
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.
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.
Other uses
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!
Maintenance
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.
Technical Data
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
