Bob Geswein
I receive many questions from members who say talking about heating and cooling equipment can be very confusing. What do terms like SEER, AFUE, HSPF, and two-stage, actually mean? Also, what is the difference between a single-speed and variable-speed heat pump?
My apologies for the heating and cooling industry. It is not fair for us to expect you to know what these terms all mean if you only purchase equipment every 15 to 20 years. And, the new technology that has improved systems in the last 10 years might just add to the confusion. I hope this article will help members better understand today’s equipment.
I am going to explain the difference in equipment to ensure you make a wise decision on your next heating and cooling purchase.
First thing, ask your heating and cooling contractor to perform the Manual “J” Heat Loss/Heat Gain calculation for your home. This calculation is critical to help ensure you purchase equipment appropriately sized for your home. If you have replaced windows, added insulation, caulked to stop air leaks or added additional living space to your home, you have altered the correct size specifications for new heating and cooling equipment that will provide maximum comfort and minimum costs for your home.
By today’s standards, heat pump technology is the most efficient of all the systems available. But there are choices within the heat pump family.
Geothermal heat pumps are the most efficient and most comfortable but also the most expensive.
Air-to-air heat pumps range for 14 SEER to as high as 21 SEER. SEER is the energy efficiency guide for a unit’s ability to cool your house. HSPF is an energy efficiency guide for a heat pump’s ability to heat your home. A higher number in both ratings is better.
Dual-fuel systems are a heat pump unit outside installed in combination with a propane or natural gas furnace inside your home. Most heat pumps utilize a supplementary heating system. An all-electric system uses an electric furnace.
But a dual fuel system utilizes gas as the supplementary heating system. Gas furnaces are rated using ARUE. The higher the better, and if this rating is over 90 percent, it is a condensing furnace that can use plastic PVC pipe for the incoming combustion air and exhaust gases. These work very well and are a good choice if you already have a gas furnace. Also, if you have grown accustomed to wood heating comfort, this is a system you should give serious thought to purchasing.
Mini-split heat pumps have some instances where they are very appropriate. Their limitation is generally four rooms per heat pump. They are very efficient since there is no ductwork. But, if you have more than four areas to heat and cool, it requires multiple units and that tends to make this option expensive to effectively condition your whole house.
This brings us to the one feature Harrison REMC suggests you give serious consideration. In fact, it is a requirement for most of our heat pump rebates.
Two-stage (or two-speed) heat pump technology is a feature that nearly all brands offer. It allows the compressor to run in a low stage (speed) when it is not so hot outside, but cooling is necessary. Then, there is the high-stage (speed), which is used when it is really hot. These units will be 16 SEER and likely 8.5 HSPF or higher.
For our average cooling season, this unit will run in low speed to cool your home 75 percent or more of the summer. It will only kick up into the high speed for the 25 percent of the summer that we need maximum cooling capacity. This two-speed heat pump running in low speed cools, continues to effectively dehumidify and uses less electricity in the process. Same goes in the heating season. It will run in low speed for the milder days and kick up to high speed for the colder days. What’s not to like about that? These units are also capable of providing more comfort than single-speed systems.
Heat pumps, properly applied, can make a world of difference to your monthly bill as well as to your comfort. Please contact me at 812-734-3538 for more information or if you have questions.
