am I saving money this way?

10 years ago I replaced my 60 year old, oil fired hot water boiler. It had a input rating of something like 125,000 btu's. I put in a 75,000 btu Peerless because that was bigger by more then 15 percent over the heat loss calc I did, which already had 10 percent added for those COLD days to come. Along with that I broke things up and added 3 more zones to reach 6 in total.

So far, so good as far as heating the house goes.

But would I have used less gallons of oil per winter if I had put in a larger boiler, like what I had, 125,000 btu's? Or would that have been a waste of oil?

I've gotten into long arguments with guys over this. What do 'ya think?

Sibi

heat

Unless the boiler was undersized and never shut off when the weather was cold, (in which case you would have saved fuel), the end result should be the same. The larger boiler would have heated faster, so it would shut down sooner. The smaller one would run longer, but since it was using less fuel per minute/hour, it would still be about the same.

Short cycles are harder on the equipment and some wasted heat goes up the flue after it completes the cycle, so longer cycles means less waste as well.

What he said. Starting & stopping wastes a lot of fuel.

The most economical boiler is the smallest possible one.

Guys,

Thanks for the info. I always thought that the min. size boiler that does manage to maintain itself would be less expensive to run. I guess it's a push in a wider range of sizes then I thought.

Thanks again.

Sibi

The most efficient boilers are those that can adjust to the heat load (a modulating - condensing boiler). Some can adjust down to as low as 20% of their maximum. This allows it to run nearly continuously during the heating season, just meeting the building's needs and maintaining a nice even comfortable temperature.