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Help decide on Mitsubishi split heat pump hyper heat or not

We are about to pull the trigger on purchasing four indoor and 2 outdoor heat pump units. Our master bedroom needs to be on a dedicated outdoor unit (cooling only) and the other three rooms (6 BTU in TV room and 15 BTU in living room on main floor, and 6 BTU in kids room upstairs) would be on the other outdoor unit. I'm a bit torn on whether to go with the Mitsubishi hyper heat series (FH) or stick with the GL series. From a cost perspective, it's nearly a moot point. I'm in Boston and there is a substantial MassCEC rebate that only applies to FH which would wash out the less cost of the GL system. My conflict is that the GL series is 5 inches smaller than FH which would be noticeable in the small TV room and kids room. But in a Boston winter, I could benefit from the hyper heat. GL series is only for 35 degrees. I heat my home with oil and there is also electric baseboard heat in the TV room and kids room which we'd no longer use once we get the heat pumps. Oil being so cheap right now (and my town's electric rates are very high) is also consideration.

Would appreciate any further insight into making the right decision!

Thanks, Vlad


  • njtommy
    njtommy Member Posts: 1,105
    I would absolutely go with the hyper heat unit. Just for peace of mind if your oil boiler fails on a cold winter day. having a back up heat source is always a plus in my eyes.
  • BobC
    BobC Member Posts: 5,202
    I just had a 12k Mitsu Mr Slim heat pump installed for my first floor (600 sq ft). It's a mid range unit with a seer of 20 and an EER of 12.5 if I recall correctly.

    They certainly don't give them away but I'll be interested to see how well it does at handling the shoulder seasons. It will never pay for itself but should be a good supplementary source of heat on late fall and early spring days.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 720
    IIRC, when I was looking at the Mitsu units, the hyper heat cut the cooling efficiency significantly. Thsi may be a factor.
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • njtommy
    njtommy Member Posts: 1,105
    They make the Hyper heat units to 30seer, but they are smaller single zones. Once you go to the multi head/multi zones the seer ratings drop. To 17 seer or so. But they will still be more efficient then standard heat pumps do to the inverter compressor and flash injection of refrigerant into the compressor to keep high discharge pressures in very cold out side air temps.
  • bluesjumper
    bluesjumper Member Posts: 3
    Thanks for everyone's opinion. I'll stick with the hyper heat. It's a multi zone unit with 18 SEER.
  • Jack
    Jack Member Posts: 1,045
    Look at the various areas that you intend to condition with the mini-splits. Compare the pricing vs the SEER/HSPF on the multis vs the singles. It was probably 2010 (todays efficiencies are higher), but I found it was better to do the bedrooms with a multi and the downstairs with a single high SEER unit. 16 seer/9.5 hasp on the multi back then and 25 seer/hspf on the single. It was a good combination.
  • MikeG
    MikeG Member Posts: 162
    I installed a 12K GL single 5 years ago in our upstairs master bedroom cooling only. In an older remodeled farmhouse in NW Ohio. I have a boiler with BB. Works great, wife loves it. A month ago I installed a 9K FH with heat and cooling. It is a single unit also for an upstairs room. I went with the FH because in the winter we keep our room 60*. I figured if we use the other room as a guest room when family visits they may prefer warmer temps since both rooms are on the same heating zone. Price wasn't that much more. The indoor unit is about 5" longer. Not an issue for me. I'm glad I went that route now since my wife is looking at also using that room for here sewing and quilting room. Haven't seen how the heat will work yet. It's been 90* for the last week here. Our winter temps average about 30*, but we do hit 0* on design days. I know some are turned off by the looks of the indoor units. My wife was happy, that was 99.9% of the install. I am considering a multi unit for the downstairs to replace a 18.5K window shaker. I know they aren't rated as high SEER, but still quieter and more efficient. Just my experience. Mike