Best Hydronic heating system?

Bill H.

I have a low mass ( Laars EBP 110 ) boiler with slantfin baseboard radiators. They radiate quickly, and cool down quickly, and I assume this is partly because they are low mass( if I understand what that means correctly ). I rented a house years ago that had a gas boiler w/cast iron, and cast iron baseboard radiators. I assume that system would be deemed "large mass". It included a manual adjustment for water temperature for varying outdoor climate. That system was the most comfortable I've ever experienced, with very little variation in temperature between the few circulator operatings. I was toasty warm all the time! I again assume it was due to "high mass" of the cast iron in both boiler and radiators.

I've come to the conclusion that the most comfortable hydronic system is to have a cast iron boiler w/cast iron baseboard radiators and an outside temperature reset. Am I correct , or am I missing some factor here? I realize cast iron baseboard radiators may be old fashioned, and they certainly are more expensive. Your thoughts, please.

Charlie from wmass

Cast iron emitters are

are more comfortable as far as maintaining long term heat. Your present emitters could be up graded with an outdoor set back so they ran for longer periods at lower steady temps. This can make up for the yo-yo effect and still allow for high efficiency.

CMadatMe

Leave Out

The cast iron boiler and then your on to something. Radiant heat, a condensing boiler and constant circulation is the best in my opinion followed by cast iron or panel rads with a condensing boiler on constant circulation.

icesailor

Systems:

Or, if you don't have a tankless coil and need to keep the boiler hot, set the high limit on the boiler to 150 or 160 degrees. That way, the heat emmitters will not deliver as much in as short amount of time.

Regardless of what type of heat emitters you have, it is the heat content of the fuel, ectracted by the extraction system (burner) and transfered in to the water. The rate of either type of emitter doesn't matter. It is the heat put in the space.

The cooler the water, the longer the circulator will run.

They say that "Cast Iron holds the heat"

I say, "Cast Iron releases the heat slower. But the same amount of heat".