Farmhouse heating options
Was hoping to get some input on our dilemma in western MA (climate zone 5). Earlier this year, we bought a 100-year old farmhouse with an ancient oil-fired steam boiler. The boiler failed its combustion safety test during our Mass Save audit, so we really need to remove it.
I would love to avoid as much as possible heating with oil.
We have had a few HVAC contractors come out, and one did a heat load calculation at 93,000 Btu/hr. I hired a HERS rater to do an independent Manual J calculation, and the result was 83,000 Btu/hr. After planned envelope/insulation measures, their “after” calculation was 64,000.
Although I know we need to do work on our envelope, the boiler is just too old and we can’t wait any longer to make this heating decision, we need to replace the heating system now and do weatherization and insulation later. We have a 99,000 Btu wood stove and 4 cords ready to go as backup.
We have been looking at 2 options:
1) Minisplit Mitsubishi cold-weather heat pump system, 2 quotes for 48,000 Btu/hr system.
2) 68,000 Btu/hr Pellet hot water boiler, with bulk pellet delivery (including 5-ton hopper in basement). I love this idea, and MA incentivizes it. However, this would also require retrofitting the entire distribution system from steam to hot water, at an additional cost of $10-12k.
There is a 7-year, 0% heat loan in MA. However, distribution upgrades are not eligible for the heat loan, thus we would need to pay $10-12k out of pocket in the pellet boiler scenario.
We like the idea of the heat pumps, but are concerned that they will not have enough capacity, especially during cold nights. Thus, we have been discussing a new option:
3) 48,000 Btu heat pump system PLUS new oil-fired steam boiler.
This hybrid scenario would cost slightly more than the pellet boiler, but I believe it would all be eligible for the heat loan, with no out-of-pocket costs. We would have a backup source on cold nights, but still would have an incentive to run the heat pumps as much as possible as a primary source. Plus, as an added bonus, the heat pumps would be installed in 2 parts of the house that don’t have steam radiators currently (and where we would need to spend additional out-of-pocket funds for radiators to be installed).
Is option 3 just total overkill? Considering we have the wood stove, should that just be our heat pump back-up?
One final thought: some folks have suggested electric resistance baseboards, as a back-up to the heat pumps during periods of very cold temperatures.
Looking forward to any thoughts on any of the above, or other possible scenarios. Thank you in advance!
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