My Unit Is Blowing Cold Air When The Heat Is On!

I've talked about this a few times in other blog posts, but it never hurts to rehash and talk about a few points. Here in eastern North Carolina and specifically Onslow county we see 90% of homes with a heat pump system. Let's start with what a heat pump is.

A heat pump in simple terms is an air conditioner that also runs in the heating season. The more complexed answer is that heat being provided for your home is actually coming from outside. You may have read that and thought i'm crazy, but every word is true. Water at sea level boils at 212 degrees, while water in Denver Colorado boils at 208 degrees. This happens because the atmospheric pressure is lower in Denver and thus leads to the boiling point being lower. When you manipulate the pressure of a substance, you can also manipulate the temperature at which it boils. In a heat pump, the pressure of the refrigerant in the outdoor coil is dropped so that the correlating saturation temp (the temp at which a substance is a mix of liquid and vapor) is below the outdoor temperature, allowing the refrigerant to absorb heat. This is the same you holding a cup of hot coffee, your hand has less heat than the coffee, so the coffee is giving some of it's energy to your hand. By the refrigerant being below the ambient temp, the refrigerant can absorb an amazing amount of energy and provide your home with heat.

As the ambient temperature drops, the amount of energy transferred into the refrigerant is likewise reduced. This means that the air coming from the vents in your home will have a linear relationship with the ambient temperature outside. Some will say this air feels cold and it is... wait if it's cold, how is this beneficial in heating a home? Assume you set your thermostat for 72 degrees and it's 32 degrees outside, it's likely with the average heat pump you will have a air coming from the vents that's around 82 degrees or so. 82 is warmer than 72, so sufficient energy is being transferred to heat the home. 82 will inevitably feel cool to the average human that doesn't live in the artic circle because our bodies are 98 degrees. Thus the feeling that something may be wrong even when it's not.

My advice to anyone with a heat pump is to never check the air from the vents, watch the thermostat. If the home stays within 1 degree of the thermostat setting, the equipment is doing it's job correctly. This will be the shortest blog I've ever written because that's the end. Please feel free to comment with any concerns or comments and as always, if you are in Jacksonville, Richlands, Hubert, Swansboro, Sneads Ferry, Nc or in the surrounding counties of Onslow or Duplin, call us and we will be happy to assist with any of your indoor comfort needs.