[shane.cummings]

Hello, I'm looking for some confirmation that I'm have the optimal configuration for my setup. I live in Maine and for the most part I exclusively use my Mitsubishi MUZ-FH15NA/MSZ-FH15NA to heat my house. However, between December and February we get some cold spells that can go into the negatives on occasion with a few single digit nights as well. The Mitsubishi is 100% efficient from 10-32 degrees and it just goes up from there but below 10% it does not do well and the layout of my house prevents it from heating a few rooms efficiently.

I have young kids and a cold wife and keep the heat pump set to 70 degrees and that works well on all but those cold days below 10 degrees. I have a forced hot water boiler as backup and am trying to optimize it so that it kicks in on those cold days. Right now I have the thermostat set to 69 degrees with a 1 degree swing so that it turns on at 68 degrees and heats the house back up to 70 degrees.

I checked with my vendor and they quoted me over $1000 to update my heat pump to sense the outside temperature and control my furnace as well. This would allow it to switch automatically to the more efficient heat source depending on the outside temperature. I'd prefer to just control this by the thermostat to avoid costs, but if it would save a lot of money then maybe I should just do it.

Is there anyone else out there that has this setup/issue and what have you done?

Thank you
Shane

 

[user_12345a]

Unless you have expensive electricity it should be cheaper to run the heatpump and just use the oil as backup. Heatpump stays on.

Need to calculate which is cheaper to be sure and not guess.

1 degree swing may be too little due to the amount of heat the rads hold - I would to a larger swing and set the oil 2F below heatpump.