Pro Star Mechanical Technologies Ltd.

Heating | Plumbing | Radiant Floor Heating | Air Conditioning | Heat Pumps | Geothermal Heat Pumps | HVAC | Boilers

Victoria, BC: 250-383-4558 | Courtenay, BC: 250-339-6914

What, exactly, is a heat pump?

A heat pump is essentially a central air conditioning system that also has the ability to heat your home during cold weather months.

It's called a "heat pump" because it pumps heat into your home in winter, and pumps heat out of your home in summer.

A heat pumps ability to both heat and cool makes it a very economical and efficient home comfort system.

Click here to see how much money a heat pump can save on your energy costs.

Click here to learn how a geothermal (or earth source) heat pump works.

How does a heat pump work?

Think of the way your refrigerator removes unwanted heat that accumulates when you open the door and place warm food inside. You can feel that heat coming back into the kitchen from the refrigerator's exhaust fan.

In a similar way, a heat pump simply extracts the heat that's present in outdoor air in winter and delivers it inside your home to keep you warm and comfortable.

In summer, the process reverses. The heat pump pulls the heat out of indoor air and releases it outside to keep your home cool and dry. A heat pump's ability to both heat and cool makes it a very economical and efficient home comfort system.

A special liquid called a refrigerant circulates between the indoor and outdoor units, absorbing and releasing heat as it travels through the loop.

What are the parts of a heat pump?

A typical heat pump installation consists of two parts: an indoor unit and an outdoor unit. The indoor unit is called an air handler and looks similar to a gas furnace. The outdoor unit looks exactly like a central air conditioner in both size and appearance and contains the compressor. See the diagram below.

Regardless of whether the heat pump is heating or cooling, the compressor is considered the "heart of the system" because it is the pump that circulates the refrigerant through the loop.

Because of its importance, experts recommend that you look closely at the compressor's reputation and warranty when selecting a heat pump.

What is the difference between air source, geothermal and water source heat pumps?

Instead of using the surrounding air, a geothermal heat pump uses the energy from the ground. Similarly, a water source heat pump uses water (a pond, lake or the ocean) as an energy source.

Probably the most basic is the difference between the temperature of the heat source and the temperature at which the heat is delivered. The larger this difference, the lower the efficiency. For the ground source heat pump, the temperature of the ground is warmer than the air during the coldest part of the winter and colder than the air during milder weather in the spring and parts of the fall.

One of the most important characteristics of heat pumps, particularly in the context of home heating/cooling, is that the efficiency of the unit and the energy required to operate it are directly related to the temperatures between which is operates. In heat pump terminology, the difference between the temperature where the heat is absorbed (the "source") and the temperature where the heat is delivered (the "sink") is called the "lift." The larger the lift, the greater the power input required by the heat pump. This is important because it forms the basis for the efficiency advantage of the geothermal heat pumps over air-source heat pumps. An air-source heat pump, must remove heat from cold outside air in the winter and deliver heat to hot outside air in the summer. In contrast, a ground source heat pump retrieves heat from relatively warm soil (or groundwater) in the winter and delivers heat to the same relatively cool soil (or groundwater) in the summer. As a result, geothermal heat pump, regardless of the season is always pumping the heat over a shorter temperature distance than the air-source heat pump. This leads to higher efficiency and lower energy use.

Click here for more information on geothermal and water source heat pumps.

A Complete Heat Pump System

1. Outdoor Unit - The heat pump. Contains the compressor, outdoor coil, reversing valve and fan.

2. Indoor Unit - The Air Handler. Contains the indoor coil, supplemental heater and fan.

3. Air Cleaner - Optional, click here for more information

4. Thermostat - Controls the heating or cooling settings. Click here for more information

How Much Money Can I Save with a Heat Pump?

The following figures are a rough guide for comparing heating sources and applications. The cost figures are as of February 2007 for Victoria, BC. The figures below are based on a home of approximately 2,000 square feet and are in Canadian dollars.

*Propane furnace @ 70% efficiency
**Oil furnace @ 60% efficiency
^Electric furnace @ 100% efficiency
^^Air source heat pump @ 2.5 COP

Where is the furnace?

There isn't any. The heat pumps takes its place. Because a heat pump simply moves heat from one place to another, there is no burning of fuel to make heat, no smoke and no fumes.

Do heat pumps have efficiency ratings?

Yes. In fact, they have two, one for heating and one for cooling. The heating rating is called the Heating Seasonal Performance Factor (HSPF), the cooling rating is called the Seasonal Energy Efficiency Ratio (SEER). In both cases, the higher the number, the greater the efficiency and the lower the operating costs.

When comparing ratings, remember that they are based on the total system, meaning the combination of the outdoor unit and the indoor unit.

Why is a heat pump so economical?

Because during the heating season, a heat pump simply has to move heat instead of making it. Unlike a furnace that must turn fossil fuel or electricity into heat, the heat pump simply collects heat that already exists in the outdoor air and pumps it into your home.

Heat naturally migrates from warmer to colder areas through windows, doors, ceilings and walls. Insulation, weather-stripping and caulk slow down this heat loss, but cannot totally eliminate it. The colder it becomes, the faster a home loses heat.

The supplemental heater helps the heat pump during weather extremes when a home may lose heat faster than the heat pump can replace it. Electric heating elements in the indoor unit turn on automatically to make up the difference.

Yes, especially if you already have a forced-air heating system, suitable ductwork and adequate insulation. Heat pumps can work with any forced air heating system ... gas, oil, propane or electric.

Heat pumps can also be installed in homes without existing ductwork and can be retrofit to almost any installation. Contact us for more information or to discuss your project.

Common Misconceptions Concerning Heat Pumps

Heat pumps are effective only in milder climates.

At one time that may have been true, but not any more.

During the seventies, when they first came into prominence, many heat pumps were installed in the southern sections of the country. The reason was that during the heating season, a heat pump's efficiency increases on mild days and decreases on cold days. The efficiency rating or Heating Seasonal Performance Factor (HSPF) is therefore higher in a mild climate than in a region where winters are severe.

Through the years, however, improvements in design have broadened the geographical range of heat pumps to almost every section of the country.

Not in terms of the end result, which is a warm, comfortable home.

In its heating mode, the temperature of the air supplied by a heat pump is not as hot as the air supplied by a furnace. Air entering a room from a heat pump is normally about 100 degrees Fahrenheit compared to about 120 to 130 degrees F from a furnace.

Thus, a heat pump warms a room gradually and more uniformly than a furnace. It's similar to slowly warming your bath water by turning the hot water faucet to a moderately warm setting rather than turning the faucet all the way to maximum hot and then turning if off and having water cool down.

Judging by their name, you might think that's the case. However, heat pumps got their name because they pump heat into your home in winter and out of your home in summer. Thus, they function like a furnace during the winter and a central air conditioner during the summer. This ability to both heat and cool makes them very economical and efficient home comfort systems.

E-mail: info@prostar-mechanical.com

All prices are in Canadian dollars and are subject to change without notice. Prices may be applicable to state/provincial taxes. Shipping/freight charges may apply.