After reading the post from HR on the "Return temp" thread, I started thinking (again) about possible condensation with the way I'm using my boilers. With condensation damage being such a big deal, and also something you apparently don't see until it's too late, it seems like a good idea to ask the pros. Our house has lots of South-facing glass, and on good sun days, we can solar heat the house, even at 20* outside. On sunny days, we'll let the WB run down to empty, mid to late morning. We shut it off with the water temp usually at 170-180. The OB (in series) is also shut off at the same time (and same temp of course), along with all circs. Now there is no flow in the system exept for some DHW being pulled from the Superstor. Depending on the Weather, we can leave everything off from 5 to a max (so far) of 12 hours. After a little bit of trial-and-error, we've become good at judging when the WB needs to be fired back up in order to reheat everything at the right time. At refire time, the WB water temp has dropped to 100-140, and the OB from 90-130, depending on length of time down. The refire sequence is WB comes back first alone, and when it hits 155 the circ to the OB loop kicks in and reheats the OB. The zone circ stays off until both boilers are back to around 175, and then we turn the zones back on as needed. This has been working really well (much better than I ever imagined it could), and has saved a ton of wood with no oil used in the process.
I thought that with no flow, and the boilers just cooling down gradually, there would be no condensation issues. But now I'm wondering about "reverse condensation" in the OB - when it's temp is 90*, and then being immediately hit with 155* from the WB. Does anyone see any potential problems with what I'm doing?
I thought that with no flow, and the boilers just cooling down gradually, there would be no condensation issues. But now I'm wondering about "reverse condensation" in the OB - when it's temp is 90*, and then being immediately hit with 155* from the WB. Does anyone see any potential problems with what I'm doing?