Heat pump, supplemental gas boiler versus oil fire boiler

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pfuso14
pfuso14 Posts: 1
in A-C, Heat Pumps & Refrigeration

debating putting a new system with heat pump with the the gas propane fired boiler to make up the difference on those cold days versus the straight up oil boiler that I have now that heats a Hydraulic baseboard any comments I am not contractor a lot of different wondering what y’all think Thanks Pete

Comments

  • Jamie Hall
    Jamie Hall Posts: 27,975

    Two different questions. The first question is the heat pump. Newer heat pumps do remarkably well even in colder climates, and whatever you do on the second question I would at least investigate installing one — probably mini-split, but there are other options. Then the second question is… why are you considering switching to a gas or propane boiler from the existing boiler? Even at current fuel prices it will take quite some time to recover the capital investment of a new boiler, so I wouldn't recommend switching unless the old boiler is giving trouble. You certainly won't save by putting in a smaller boiler — that would be a real mistake, as you need what you have on the coldest days, when the heat pump will lose capacity.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • BenT123
    BenT123 Posts: 8

    Why are you tying boiler replacement with heat pump installation? Are you considering Air to Water heat pump system?

  • pecmsg
    pecmsg Posts: 7,634

    I like heat pumps and eventually they will be the only choice, but the technology is not quite there yet. Add to that the lack of training for techs.

    I still recommend keeping the oil or gas as your back up for WHEN something fails. Keep in mind all those parts are proprietary to that equipment manufacture. Not something you go to a local supply house and get off the shelf.

  • Hot_water_fan
    Hot_water_fan Posts: 2,249

    I’d do the heat pump but keep the oil. The trick with a hybrid system is not to overpay on the systems. You don’t need the best of either, their weaknesses cancel out

  • hot_rod
    hot_rod Posts: 28,699

    you want to do some calculations first, the design heat load, how many feet of fin tube. The A2WHP like 120 and below operation, but the fin tube may not have enough output at those low supply temperatures.

    This issues give you some inside on those legacy high temperature system conversion

    https://www.caleffi.com/sites/default/files/media/external-file/Idronics_25_NA_Lowering%20water%20temperature%20in%20existing%20hydronic%20heating%20systems.pdf

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • HVACNUT
    HVACNUT Posts: 7,784

    @pfuso14 , are you thinking of converting from oil to gas and installing a heat pump? The wording is a little confusing.

    I just upgraded my oil fired boiler serving baseboard, radiant, and domestic hot water. My CAC is also due for replacement and I'm leaning towards a 2 stage heat pump. Not an inverter system. Simple middle efficiency 2 stage. Even though my new boiler is very efficient, the way things are going, running the heat pump might be cheaper. And whether we like it or not, it is the future.

  • winnie
    winnie Posts: 80

    As @Hot_water_fan says, you don't want to pay for the best of both systems. Remember that in a hybrid system you are getting fewer operating hours out of each system. So you might pay for a high efficiency heat pump, but then stick with a low efficiency (but cheaper) fuel burner. Or if you are only using the heat pump on warmer days you might select a lower efficiency heat pump and pay more for efficiency at the fuel burner.

    I've personally be quite happy with the air-air minisplits that I installed and the 83% efficiency oil/steam system that came with my house. With oil vs electricity prices this year, I expect to use the minisplits for most of the heating season, switching to oil only on the coldest days. If your boiler only runs 100 hours per year it doesn't pay to buy the most efficient boiler.

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