Air-Source Heat Pump Heat Strips
Building a home in Zone 6B (cold and dry), and installing a Daikin VRV Life electric air source heat pump, which is rated to -4F. I noticed a line item on my HVAC pricing for $1284 to install heat strips. I questioned why they are needed and the response was, esoterically, that it’s something to do with Manual J calculations.
My state operates off 2018 IMC and mechanical sections of the 2018 IRC. I searched both codes and can’t locate this requirement. We’re installing a wood stove; if the heat pump fails in the wintertime for any reason – pump, refrigerant, power failure, etc. – we’ll have a fire going. Honestly we’ll probably have a fire going a lot of the winter regardless.
Electric heat strips don’t work if the power goes out, they only kick in when the heat pump fails for some other reason. And when they do kick in they use a lot more electricity than the heat pump. I’ve also read on this site that they can kick in by mistake, which is concerning.
My question is: what is there in the Manual J process where backup heat, and backup heat that doesn’t factor in the wood stove, becomes a requirement?
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