boiler replacement

mike faust

This is a residence (and a fairly small one at that... around 2000 sq') I guess, more accurately the 1st floor is suspended concrete over unconditioned basement area. Low mass or "cold start" type boiler would eliminate standy loss from domestic water demand....Yes?? We carry laars and thermo-dynamics. Do you have experience with any condensing oil boilers?????

mike faust

boiler replacement

I am bidding a boiler replacement that currently has two zones. Zone 1st floor has large steel pipe in slab radiant. The slab is hung over the basement. The 2nd floor zone is just aluminum finned baseboard. Customer currently has an old oil boiler with domestic hot water hook up. What is the best way to save on oil useage in this application. I was thinking: Switch to low mass with primary /secondary piping to supply the two zones with different temperature demand. Am I on the right track.

Brad White

I think so

Definitely two temperatures and P/S with OD Reset.

Not sure how the Owner runs the place though. The slab (hung? Not sure what you mean but I assume higher mass), would be kept at a more constant temperature and the fin-tube would be a rapid response effort.

Not sure you need a low-mass boiler specifically and for that matter, what is low mass in oil? A gap in my understanding, anyway. But if the slab-side is the larger load and mass, once it is warm it essentially "drops out" of the picture. In other words, don't count on it as a buffer.

Here is a second thought although maybe not in a tight bid market: Does it make sense to use two smaller boilers twinned together, allowing some redundancy and quick pick-up while the fin tube area can use one of the modules after the slab has reached temperature. Standby capacity may be welcome if it is a business that cannot shut down. Just a thought.