The Big Debate! Straight Cool vs. Heat Pump

12 Nov

First thing to take into consideration is the climate you’re in.  If you happen to live in a northern region where temperatures can easily plummet below 40°F in the winter, a heat pump system alone may not be enough to maintain your desired level of comfort.  As strange as it may sound, a heat pump works by capturing the heat outside and moving it inside.  Now you may ask yourself, how is it supposed to capture any heat when its 42°F outside?  Well, the truth is that any temperature above absolute zero (around -459°F) contains some stored heat energy.  In other words, the temperature difference between any two temperatures is heat energy ripe for the taking.  Since it becomes very hard to extract the heat from temperatures below 40°F, it is recommended that a secondary heat source be included when a heat pump is installed in climates prone to colder weather. Even here in Florida, we always install auxiliary electric heat strips for the instance that it gets abnormally cold or in emergencies when the heat pump may not be running properly.   If you’re in an area that averages below 40°F in the winter, your best option would be a straight cool system with a gas furnace (whether it be Natural or LP).  If a gas furnace isn’t an option, a heat pump system with auxiliary electric heat strips would be the next best choice.

The next thing you will want to consider is your comfort level.  If you are used to the heat provided by gas furnaces or electric heat strips, the change to a heat pump system may leave you scratching your head.  Supply temperatures of 120° F are normal for gas and electric heating systems.  While this does allow for rapid heating of the house, it can also leave cold spots.  With temperatures this high pumping into your home, the thermostat may satisfy quicker than it should, leaving areas of the home colder than the “set to” temperature.  The main difference in the design of the heat pump is that it does best in maintaining a consistent temperature.  You may notice that when heating with the heat pump only, the air temperature at the vents may feel cool.  Average temperature for a heat pump in heating mode without the auxiliary electric heat strips is between 80° F-90° F.  This is high enough to heat the house as most people will keep their heating temperature set to between 68° F-72° F. This makes for a more evenly felt temperature throughout the house.

Lastly, you want to consider your energy efficiency.  Heat pumps are gaining the reputation of being the go to system for energy efficiency.  By taking out the need for electric resistance heating, your electric consumption will be reduced.  The argument has been made that when heating, a heat pump system is running both the indoor and outdoor equipment, so one could assume it would be more costly than just an air handler with electric heat strips.  The difference is apparent when you look at the amp draw.  An amp draw is the measure of electrical current flowing through a conductor or the energy being consumed, in this case, by the system.  An air handler by itself can sometimes pull about 1 amp when just blowing the air.  With the electric heat strips active, it may pull 25 or more amps.  A heat pump on the other hand, will pull about 6 to 10 amps total plus the 1 amp the air handler is pulling.  You are looking at a difference there of around 14 amps less power consumption with the heat pump system versus and standard straight cool with electric heat strips.  Again, when temperatures get below the 40°F mark, your heat pump system will rely on its secondary heat source to help make up the difference.

As you can see, there are a lot of things to take into consider when deciding what kind of system to install.  We always recommend having a professional come out and assess your home and concerns before making a final decision.  Call us today and let use help you make this important decision.

Chris Crites
HVAC Specialist
Tropical Air of Central Florida
407-884-6050

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One Response to “The Big Debate! Straight Cool vs. Heat Pump”

  1. D. Huffman November 12, 2012 at 2:33 pm #

    Thank you Chris for keeping so many informed and for Keeping us all Cool (and Warm) during the Summer and Winter months.

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