Heat Pumps versus Central Air Conditioners

In this age of high energy costs and environmental awareness, choosing the right cooling system for our homes is a crucial decision. The two main options are air conditioning systems or heat pumps. Let's take a look at how they compare.

Heat Pumps:

Heat pumps actually operate as both heating and cooling systems. In the cooling mode, they take heat from the internal air of the home and pump it to the outdoors. To produce heat, they collect it from air, water, or the ground outside and move it inside. Here's a simple way to describe what these units do: they move heat from one place to another. Both heat pumps in cooling mode and air conditioners use the Seasonal Energy Efficiency Rating (SEER), which tells how efficiently they use electricity. The higher the rating, the less power they consume. Heat pumps must now have a SEER of at least 13. A higher SEER is desirable in a warm climate because of the need to more frequently provide cool air to the home. Heat pumps also are rated according to the Heating Seasonal Performance Factor (HSPF), which refers to the power used when the unit is in heating mode. Because a heat pump's coils are outside, they become ice collectors during the winter. Heat pumps use burners to melt the ice and push warm air into the house.

Air Conditioners:

Air conditioners manufacture cool air by evaporating Freon or some other refrigerant product. Basically there are coils both inside (for cold air) and outside (for warm air). The units contain a compressor to change Freon into hot, high-pressure gas that travels through the coils. As it does so, it loses its heat and becomes liquid; the liquid in turn goes through a valve and evaporates into cold, low-pressure gas. When it enters the coils, it absorbs the indoor heat and lowers the temperature. Residential air conditioners also use the SEER as a measure of their efficiency. (Larger commercial units often measure energy efficiency by the Energy Efficiency Ratio (EER). This measure shows the number of British Thermal Units (BTU) of cold air provided for each watt of electricity. When talking about cooling units, 1 ton is equal to 12,000 BTU. To find the EER of an air conditioner, divide the BTU rating by the wattage. For example, let's say that a 12,000 BTU air conditioner uses 1600 watts to run -- then its EER (12,000 divided by 1600) is 7.5. The higher the EER, the more efficient the air conditioner, so a higher EER is more desirable. The drawback is that more efficient units are more expensive.

High Efficiency Systems:

High-efficiency air conditioners and heat pumps cost more up front than mid-range or minimum-efficiency units but will result in the lowest monthly energy bills and often include additional energy-saving features. Experts say these 16 SEER (seasonal energy efficiency rating) or greater air conditioners and heat pumps make sense if you want to make a long-term investment, live in an area with high electricity rates or long air-conditioning seasons, and are willing to pay more at the time of purchase so you can reduce your use of electricity. Most high-efficiency air conditioners and heat pumps are two-stage units, which cool efficiently with less on/off cycling, and they all use the more environmentally friendly coolant R-410A (Puron) instead of R-22 (Freon).

R-22 or R-410A Refrigerant?

Most air conditioners and heat pumps use a refrigerant known as Freon. Emissions of this refrigerant into the earth's atmosphere are known to deplete the earth's ozone layer that protects all living things from harmful rays from the sun.

Currently, in the U. S. alone, there are over 2,500,000 homes that enjoy comfort as a result of non-ozone depleting Puron� refrigerant in their air conditioners or heat pumps. By choosing higher efficiency equipment that uses Puron refrigerant, you'll enjoy enhanced comfort, more reliable products, money savings and environmentally sound operation all at once. At the same time, you'll protect yourself from the potentially rising service costs associated with Freon refrigerant.

Chemically, Puron refrigerant is an environmentally sound 50/50 blend of two separate refrigerants, R-32 and R-125. Consumer products featuring Puron refrigerant were first marketed in 1996.

Are you paying a reasonable price for your HVAC System?

There are essentially two costs when purchasing and installing a new central air conditioner: equipment costs and labor costs. Depending on your situation, you may be able to reduce your costs in one or both of these areas.

Probably the single greatest cost-saving solution is to buy your air conditioner from a direct-to-consumer retailer, and then hire a licensed HVAC contractor to install it.

You will need to work with a good HVAC contractor when you install a new central air conditioning system. Make sure that you get quotes from at least three contractors. This will ensure you a low, medium and high bid, and give you a good sense of what it is reasonable to pay. Also, make sure to screen your potential contractors to ensure that they have happy customers and no complaints.

Choosing the right size Central Air Conditioner or Heat Pump System

It is important to have an HVAC Contractor perform a load calculation before you decide which size air conditioning system to buy. If you install an air conditioner which is too large, it will cycle on and off too often, substantially reducing the efficiency of the system. Too small, and your air conditioner may not be able to meet the demands of a hot, humid day.

The industry standard load calculation is called the Manual J calculation. It takes into account the size of your house, the amount of insulation installed, the square footage, and a host of other factors.

Is a Heat Pump the Best Choice?

Since a heat pump can both heat and cool a house, wouldn't you always rather buy a heat pump than a central air conditioner? And wouldn't you rather have a single piece of equipment to purchase, install and maintain than both a central air conditioner and a furnace? While the answer may be this simple, you should consider several factors.

The seasonal weather in your region is probably the most important factor in this decision. If the temperature rarely dips below 40 degrees Fahrenheit, you can probably heat your home more affordably with a heat pump than a furnace. However, if the temperature is often colder, you should consider having a backup heat source. Many people choose a gas or oil furnace to serve this purpose -- both for reasons of cost and because a furnace can more easily maintain warm temperatures when the difference between the temperature outside and inside increases.

Second, heat pumps are generally more expensive than a central air conditioner of the same efficiency and capacity. For example, at one direct-to-consumer retailer, a 1.5 ton, 13 SEER Rheem heat pump retails for about $100 more than the equivalent 1.5 ton, 13 SEER Rheem central air conditioner. Contractors may also charge more to install a heat pump than a central air conditioner.

A third criteria to consider is longevity. Since a central air conditioner is typically only used during the summer months, and a heat pump is used during both summer AND winter, the lifespan of a heat pump is typically shorter than that of a central air conditioner. Maintenance costs are typically higher as well, since the compressor, controls and other components will run more months out of the year.

Finally, natural gas and oil have historically been more affortable than electricity. However, as petroleum costs have skyrocketed in the past months, this may not be true in your area. ( Of course, this also varies by region. Some, for example, have pointed out that the many hydroelectric dams in the Pacific Northwest of the United States often result in electricity costs lower than natural gas costs.) Since heat pumps almost often run on electricity, you'll want to consider whether a gas furnace would be cheaper.

These excerpts were taken from Furnace Compare's website under the link:

http://www.furnacecompare.com/buying_central_ac.html#q7