Posted by Harold Kestenholz - Hydronic Network on August 25, 2000 at 21:22:40:
In Reply to: Best Natural gas boiler for radiant heat posted by David Sperry on August 25, 2000 at 17:59:22:
There are many natural gas boilers available for radiant heat. All of the metals you mentioned are available. Cast iron manufacturers address the condensation problem at low temperatures by recycling warmed water back into the boiler or using an injection system to keep the boiler warm; so you have the proven technology of cast iron. The other metals are available in boilers in the efficiency area up to 94% AFUE.
Not every boiler is available in every area; so IMO the most important question is which boiler is carried by the supply houses and which installer has the best reputation and service. New boilers have to have a fan and electronic ignitions to be efficient. If you have the most efficient boiler, but unavailable parts and a learning curve for your technician; then maybe slightly less efficiency and the best available parts and service is the best deal.
After all - saving 2% AFUE on an $800 yearly fuel bill is only $16 per year. I pay that for peace of mind and a trip to MacDonald's.