By Jeb Mirczak
Welcome to spring. I have been enjoying the warm sun lately, as I’m sure you have, but winter is never far away. Now is the time to talk home heating if you want to get installation done before next winter. Has your furnace been making funny noises? Are you interested in reducing the carbon footprint of your home? Want to lower that home heating bill? If you answered yes, let me tell you about the heat pump heater I had installed in my home.
To put it simply, a heat pump works by moving heat from a cold area to a warmer area.
It’s powered by electricity and circulates refrigerant between indoor and outdoor units. You are probably familiar with its application in your fridge or air conditioner. Modern heat pumps can run in both directions, providing air conditioning in the summer and heat in the winter.
Heat pumps use much less energy than a gas furnace or electric resistance heaters.
The heat pump always wins because it doesn’t have to make heat. It takes heat that already exists outside the house and moves the heat inside. Because of this, heat pumps are able to achieve efficiencies above 100%. You’re probably saying, “That’s impossible. Over 100% means that I would get heat for free.” Exactly! A typical value for Truckee/Tahoe is 260% efficiency. That means for every 100 watts of electricity you put into the system, you get 260 watts of heat into the house.
How about some math for the nerdy types. I’ll go over the numbers for my home. Get out your utility bills for the last year if you want to play along.
With a propane gas furnace:
I used 324 gallons of propane each year for home heating. This cost $1,210 per year.
The carbon footprint was: 324 gal x 12.7 = 4,115 pounds of carbon dioxide. The heat supplied to my home was: 324 gal x 91,500 = 29,646,000 British Thermal Units (BTUs).
With a heat pump heater:
The electricity to make the same heat: 29,646,000 BTU / 8,871 = 3,342 kilowatt hours (kWh). This costs: 3,342 kWh x 0.132 = $441.
The carbon footprint is: 3,342 kWh x 0.303 = 1,012 pounds of carbon dioxide.
These are impressive numbers. With a heat pump, my annual bill is about $850 lower and I cut my carbon emissions by 75%.
A common argument I hear is, “there isn’t enough heat in cold air to heat a home.” This used to be a problem, but new units have modern, variable-speed compressors that provide better performance. The Fujitsu system that I have will produce heat in outside temperatures of -15 F. Sure, those are marketing numbers, but how does it work in reality?
The coldest it has been since I installed the heater is single digits, and the heating kept up on those cold nights and mornings. We keep the house at 50 F while sleeping and 60-65 F during the day. For those of you who prefer the tropics, I set my house to 74 F on a day when it was 22 F outside. It was no problem. If you work with a HVAC professional to correctly size your system, these heaters will provide heat all winter long.
If any of this sounds cool (… or warm), get some more information at energy.gov/energysaver/heat-pump-systems or from the manufacturers (I recommend Mitsubishi or Fujitsu). Unfortunately, I was not able to find any local HVAC contractors who install heat pumps (yet). Run a quick search in Reno or Sacramento and you’ll find plenty of specialists who can help you out. Cheers to a smaller carbon footprint.
~ Jeb Mirczak is a guy who lives in Truckee. He has a wife and a dog and will wave back at you.