Basement Ceiling Radiator Sizing

Matthias

Hi Everyone. Looks for some guidance on sizing ceiling mounted radiators that use ductwork and vents upstairs. There are 3 radiators hanging in the basement ceiling ceiling with ductwork made out of wood, which has wooden sliding dampers incorporated. I can't see the radiators from below but was able to see one through a floor register. It looked like the HB Smith 'The Smith Convector' or the Utica Type A cast iron convectors that are listed in the EDR book. Anyone have any guidance on where to find a more accurate sizing?

mattmia2

Those are called indirect radiators. You have to see at least enough of them to count the sections and see how big a section is and hopefully identify who made them.

Pictures might help.

Matthias

@mattmia2. Thank you! Unfortunately, that isn't possible without removing the wood that surrounds them and the wooden ductwork. I'm guessing that each is 75 ft². I'm basing this off HB Smith radiator that is listed in the EDR book and the indirect radiator bring 3'x3'.
The currently boiler has 896 ft² of steam. When I add up the ft² for the existing ARCO Rococo radiators, I got 262 ft². With the assumption that each indirect radiator is 75 ft², the total ft² I come up with is 487. The Weil McLain EG-55 produces 521 ft² and the EG-65 produces 621 ft. I think I'll lean towards the EG-65. What do you think?

mattmia2

Is this 1 or 2 pipe? What is the heat loss of the house? With 2 pipe if you're under it is easy to still get it in balance, with 1 pipe if it is too far under you might have trouble getting all of it to heat.

What happens with the current boiler, does it build pressure and if so how fast? Is everything hot when that happens? You can get some idea how well matched the current boiler is(unless it is sending steam up the chimney).

Matthias

@mattmia2 I do not know the answers to some of those questions as this would be a new customer. However, when I went around the house, all radiators heated up. According to the pressure gauge on the system, it went up to 5 or 8 PSI and the system shut off. I did find a main air vent, which I assume doesn't work. The plan was to change that as well.

KC_Jones

Matthias said:

@mattmia2. Thank you! Unfortunately, that isn't possible without removing the wood that surrounds them and the wooden ductwork. I'm guessing that each is 75 ft². I'm basing this off HB Smith radiator that is listed in the EDR book and the indirect radiator bring 3'x3'.
The currently boiler has 896 ft² of steam. When I add up the ft² for the existing ARCO Rococo radiators, I got 262 ft². With the assumption that each indirect radiator is 75 ft², the total ft² I come up with is 487. The Weil McLain EG-55 produces 521 ft² and the EG-65 produces 621 ft. I think I'll lean towards the EG-65. What do you think?

If you have 487, you put in the EG-55, but honestly the EG-50 would be more than adequate. the EG-65 is ludicrous.

I'd be doing my best to figure out the indirect radiators if you have any level of uncertainty. Putting in a bigger boiler "just because" should never, ever be the answer.

Jamie Hall

It went up to 5 or more? Eek. That you need to fix, if nothing else. Get a reliable low pressure gauge. Check the setting on the pressuretrol. Check the pigtail. That much pressure will kill any vents or traps you have or put on.