Condensing Modulating Boiler

[lld]

Is it possible for the high efficiency boilers to reset to a Delta T rather than the outside reset? In other words, can they be made to supply 180 degrees and modulate firing rate on load demand?

The reason I ask is that I have baseboard heat and that is designed for 180-degree supply temperature. I have salespeople who are trying to get me to go with a high efficiency boiler that modulates to an outside air temp. I live in Alaska and believe it not I hate being cold!

Thanks so much – this is a great site!

[MechComf]

The Munchkin modulating boiler will modulate on return water temp. It is a high efficiency condensing boiler. Factory default is 180 degree supply water and can be adjusted to fit your needs.

[larobj63]

Just know that a condensing boiler is only actually condensing at lower return temps. The whole point of outdoor reset is to keep the boiler condensing as much as possible while matching the heat loss of the house - which is directly related to outdoor temp.

Now, you're in Alaska, so the time spent with lower supply temps is probably going to be a lot less than it would be down here. But the principle remains the same. Your baseboard being "designed foe 180" is only really relevant on design day conditions. Warmer days allow the use of lower temps.