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Heat loss, what size boiler do I need?

DanHolohan Member, Moderator, Administrator Posts: 16,526
This discussion was created from comments split from: Heat loss, what size boiler do I need?.
Retired and loving it.


  • R2.0
    R2.0 Member Posts: 99
    I just did an oil-to-gas conversion on a very similar house. Some observations:

    1) I used the Taco FloPro software to model the system and get loads. Unless you are very familiar with HVAC systems, I don't recommend it - it is NOT very user friendly. On the other hand it lets you model the room loads very accurately.

    2) I chose a design temp lower than recommended. While I agree with the above posters that design days happen only a small percentage of the time on an historical basis, that might be changing. I won't get into Global Climate Change here, but I will say that, over the past 3 winters in my area, we have had pretty long stretches that were below the ASHRAE design temps. Whether that's an outlier or a trend I don't know, but I'll say that I did let the prospect of 2 weeks of a chilly house with the boiler running full out may have swayed me. :\

    3) Someone mentioned a gas gun conversion. I wish I had looked more closely into that, but when I read that Burnham didn't recommend it I dropped the idea. But if it's possible, and you currently use a tankless coil, look up IceSailor's Electric HW Heater to Storage Tank Conversion. It's what I will be doing at my place as soon as I can wrestle the old electric tank I have from it's location.