Fine-tuning nbp insulation to balance basement and upstairs temps

Precaud

On most days, i.e. sunny ones, my steam system only works the night shift, from say 5pm to 9am. On those days, basement temps are a comfortable 69-70F. But on cloudy days, steam carries the heat load all day, and the basement is way too warm, 76F yesterday. The mains are well insulated from the upper header and out. From upper header to boiler, the pipes are bare. I need to insulate some of it to better balance the basement temps.

I can see that this will be a trial-and-error process. Should I prioritize working from the upper header down, or from the boiler up? My guess is the latter, but I wanted to get your thoughts.

Hap_Hazzard

Have you thought about putting some fin-tube baseboard in your wet return with a valve to bypass it on warm days?

Precaud

That sounds like a major project...

Precaud

Noone weighed in with their opinion, so I decided to start at the lower header around the boiler, where delta-T is the highest.

I also decided to go with materials that I have laying around in abundance, and not being used.

1.25" high-density cotton batting that we used to line ported speaker systems with back in the 90's. Conveniently, the rolls are 13" wide, perfect for wrapping around a 2.5" pipe.


White polystyrene sheeting to wrap it in.


And secured with 22 ga. hookup wire. It works great and has that cool "semi-pro" look.


The solar heaters drove the house up to 78F today, so I've opened a door to cool the place down so I can fire up the boiler! Will be interesting to see what (if any) difference this makes tonight.

Precaud

This combo works great. I think more important than the convective insulation is, it kills the radiation into the nearby walls. Radiating heat into walls near the insatiable concrete floor has always felt like a bad idea. If the whole foundation had exterior insulation, it would be different...

I timed heat-at-upper-header to steam-at-mains-vent-pipe from a cold start, and saw a 5% decrease in time compared to the uninsulated case. Not huge, and maybe not the most useful comparison, but something.

I think I may fit covers for a couple of the tees as well. They're high-mass with concentrated horizontal radiation.

Tue/Wed is supposed to be cloudy, so we'll see what basement temps are like then with the steam running all day.

pecmsg

That header looks awfully low!

May want to have that checked before insulating.

Precaud

Thanks, but the system is working fine, just looking to fine-tune some things.

pecmsg

Precaud said:

Thanks, but the system is working fine, just looking to fine-tune some things.

OK

Just never seen that piping diagram in any manual!

Precaud

Nor I. But it doesn't seem to be a problem in this case, so...

ethicalpaul

I would start from the top down, not sure it matters much

pecmsg said:

That header looks awfully low!

May want to have that checked before insulating.

Yeah we’ve all looked at it in an earlier thread. It’s that one with another header above it from an earlier larger wood boiler 😅

BobC

@Precaud I had my old Delco steam boiler replaced in the early 90's, the work was done before i really knew much about steam and while i was at work. This was a Burnham v75 that was almost 3X what I needed.

The boiler was installed in a day and they came back a week later to skim and remove the old hulk. The header on that boiler was about 10- 12" above the NWL and that boiler never complained a bit. Steam is a finicky thing, what won't work in one instance works fine in another.

If it works let it be.

Bob

Precaud

Thanks @BobC , that's an interesting story. And I'd guess that was probably in a locale where steam was commonplace as residential heating, and installers would gain experience as to what works and what doesn't.

That was not the case here. My son and I were thinking about it the other day, and neither of us can recall a house or knowing a person who had steam heat. Hot water, yes. But no steam. Steam pretty much requires a basement to install and maintain, and those are uncommon here.

I had to drain 1/2 or more of the water yesterday to remove an old LWCO that was still hanging on the sight glass feeds. If its any indication of operating condition, the water was quite clean. It was last drained/flushed about 18 years ago. So I agree; let it be if it works, and works well.