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Community and Q&A

Converting to Hyper Heat

MattBoston | Posted in Green Products and Materials on

We have a 3 year old Mitsubishi mini split system in our Boston area house. We didn’t go with hyper heat at the time. Wondering if the only cost to move to hyper heat is just replacing the outside compressor or do we also need to change out the inside wall units?

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  1. walta100 | | #1

    The only way to know is to read the model numbers off your indoor units and take that information to the manufactures web site and see if your indoor model numbers are on the compatibility list for the outdoor unit you are considering.

    Most contractors are not going to like you plan because if there is a problem in the warranty period you will expect them to fix it at no cost but since you are reusing old equipment any fault in one of the old parts will make for an uncomfortable conversation. Also, when they sell less equipment, they make less profit.

    Why would you want to move to Hyper Heat now? How many hours a year if it below zero? My guess is with the price increases in the last 3 year this upgrade will cost 25% more than you paid for the full install. It seems unlikely the math would show the energy saving ever recovering what it is likely co cost.


  2. MattBoston | | #2

    Thank you.
    The system as it is only hears efficiently when it’s above about 30 degrees. We have plenty of days that are between 0 and 30. It would be nice to be able to reduce the amount of oil use, especially when prices for oil are up. I figure we’re using 2.5 gallons a day in the part of the house that has the mini splits. At $4 to $5 a gallon for about 90 days that’s about $1000.

  3. Expert Member
    Akos | | #3

    Which outdoor unit you have?

    Lot of the Mitsubishi non-hyper heat outdoor units actually get better efficiency in cold temperature than their hyper heat system. They just loose capacity as it gets colder. Most also also missing a base pan heater which is an accessory you can add on.

    I'm with Walta though. Not sure how much sense it makes to replace the existing system. A better option is to add an additional single zone hyper heat system, say a ducted unit into the basement, and have it provide the missing BTUs.

  4. walta100 | | #4

    My guess is your COP is not as bad as you imagine it is below 30°. My guess is your COP over 3 at 30°F and over 2 at zero.


  5. gusfhb | | #5

    A quick perusal of the units says you need to replace both. Truth is buying the set is not that big a punishment, as they are priced better that way.

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