Steam Heating Capacity - buying an old house...

Steamhead (in transit)

and the radiators are hooked up in parallel. We would call it 2-pipe direct return. The easiest way to "zone" the second floor would be to use thermostatic radiator valves in rooms you want to keep cooler, like bedrooms. The pic shows one in my house.

Those B&G 100 circs and the equally popular Taco 110 units were often too big for the systems they were used on, especially on old gravity systems. Also they required oiling, which many folks forgot until the bearings froze up! Those little circs are available in lower capacities and use the system water for lubrication.

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GWilson

Is my steam boiler sized correctly? Buying an old house...

I am buying an old rowhouse near Philadelphia that has a steam heating system, or at least I think so! In the basement is a Weil-McLain CG boiler 50 psi Model # CG-3-SPDN (series 12, natural gas, 70,000 btu/hr, DOE heating capacity 58,000 btu/hr). I think it is 10-15 years old. Looks to be in good shape and has a yellow DOE energy efficiency label on it (rated at the bottom of the efficiency scale).I'm wondering whether it is sized correctly to the house.

The house has two floors and a basement. I don't see any radiators in the basement, but there is a radiator in the garage! The two side walls are common to the adjacent buildings. There are eight rooms on the two floors, each with a radiator.

Can anyone tell me if this is a half-way decent quality boiler? Does it seem to be the correct size for the building and radiators? I have a feeling they didn't spend more than they had to, although all of the plumbing work appears first rate.

Any comments or advice would be appreciated. I'm completely new to steam heat.

Brad White

Did you ever come to the right place...

Without a heat loss calculation but more importantly knowing the size (EDR or radiant output) of your radiators, it is hard to say. If a row house but not on the ends, the boiler size does not seem out of line, probably one of the smallest.

There is a presumption that it has heated over the past 12 years I would hope!

The 50 PSI rating puzzles me. Steam boilers for residences are 15 PSI and if water, rated for 30. 50 PSI is a commercial standard, so I am curious.


W-M is a good name among others, every manufacturer has it's adherents and detractors. Others with more direct experience especially on service and warranty calls over time can offer far more insight on particular models and vintages than I can.

Thinks to look for would be to find a copy of the owners manual and install manuals. Compare the near-boiler piping to those requirements. Near-boiler piping is really "part of the boiler" that manufacturers have not been able to ship to you in the crate

Proper venting of the mains, venting of the radiators, low exit velocities, Hartford Loop, decent header take-offs, insulated piping, as low an operating pressures as possible, all make for a happy quiet system.... Much more to it than that, but it is a start.

Have you bought Dan's "We Got Steam Heat"? Strongly suggested. You can sit in the basement and read stories to your boiler.

GWilson

Pics of system under discussion

I've posted some pics of the system I am asking about:

http://www.quakertech.net/heating/heating.html

Daniel_3

My oh my that looks like a two section boiler and it looks to be able to take care of 50 sqft of radiation and not 50 psi's. (Just Kidding)

It does look very small though and the near boiler piping is very poorly done. It will need to be re-piped and like Brad said a proper heat loss and connected laod calculation performed for a properly sized boiler. If you have 9 radiators that boiler will definitely not be able to take care of the load.

JBee_2

That is not a steam boiler that you have but a hot water system.

Brad White

News x 2: Your Hamster is a girl. And it is pregnant....

For one thing, Glen, it is not steam. It is hot water! You are in a better position than you think in that if you do replace the boiler and can solve venting, you can use a ModCon boiler.

It probably is a 3-section as you said, not a 2-section which I have never seen but I could be wrong.

I did not see the expansion tank (may be above, between joists) but make sure the connection point is on the suction side of the circulator. The circulator is on the inlet side of the boiler in the photos. The expansion tanks traditionally come off the boiler block itself in old systems as a bonus air-release means, but this puts the expansion tank on the wrong side of the circulator. Pump away!

More to tell, but you do not have a steam system. Probably an older converted gravity HW system which gives you more options such as outdoor reset and modulating condensing combustion if the venting can be accommodated.

GWilson

My hamster is pregnant?!?!?

Brad and all,

Our local supermarket was recently remodeled and took down our favorite sign which had a typo in it selling "Hampster Food." Someone had a sense of humor, and not just for the spelling since "Hampster" was one of only three categories of food for that aisle.

Anyway, thanks for the info. It's good to know that it is a water system since that is much less mysterious to me. But now it really looks small. There is definitely a tank up between the floor joists.

Are you dead certain about the circulator being on the wrong side? So, does that mean it is pushing the return water back into the boiler instead of pumping out to the radiators? That's a pretty big mistake. I used to deliver Bell & Gossett circulators from a distributor to local plumbing supply houses, and I don't remember selling any tiny pumps like this. Most of the pumps we sold were about the size of a shoebox. And then there were the big ones that went onto the truck by a crane...

We sold skids and skids of these Series 100's
http://www.bellgossett.com/productPages/Parts-SERIES-100.asp

Speaking as someone with an electronics background, are all the radiators in a system like this connected in "series" or might some of them be in "parallel" ? I'm wondering how difficult it would be to divide the house into two zones with a separate thermostat for the upstairs?

Glen

GWilson

My hamster is what?!?

Brad and all,

Our local supermarket was recently remodeled and took down our favorite sign which had a typo in it selling "Hampster Food." Someone had a sense of humor, and not just for the spelling since "Hampster" was one of only three categories of food for that aisle.

Anyway, thanks for the info. It's good to know that it is a water system since that is much less mysterious to me. But now it really looks small. There is definitely a tank up between the floor joists.

Are you dead certain about the circulator being on the wrong side? So, does that mean it is pushing the return water back into the boiler instead of pumping out to the radiators? That's a pretty big mistake. I used to deliver Bell & Gossett circulators from a distributor to local plumbing supply houses, and I don't remember selling any tiny pumps like this. Most of the pumps we sold were about the size of a shoebox. And then there were the big ones that went onto the truck by a crane...

We sold skids and skids of these Series 100's http://www.bellgossett.com/productPages/Parts-SERIES-100.asp

Speaking as someone with an electronics background, are all the radiators in a system like this connected in "series" or might some of them be in "parallel" ? I'm wondering how difficult it would be to divide the house into two zones with a separate thermostat for the upstairs?

Glen

Brad White

Expansion Tank Location

Hi Glen-

Hard to tell from the photos where the expansion tank actually connects but 90% of the installations I see more than ten years old are wrong...

For your own edification, I would trace out your system as a diagram to identify which are supplies, which are returns. I too see this as "parallel" piped, with each radiator or stack of radiators served in parallel. As Steamhead noted, this is an ideal situation to install TRV's on each radiator. Individual low-cost control, especially if you install them yourself. For me (homeowner, engineer and handy in general), I budgeted an hour to an hour and a half per installation starting with a drained-down system. I did seven radiators in a nine-hour day so not too far off.

Wet-rotor circulators are pretty much a standard but if you ever change out the boiler and/or install them, put a strainer upstream to catch loose particles which are endemic in old piping. The 3-speed circulators are very flexible. Even the lowest speed, given your larger piping, may do your entire house.

GWilson

Tank location..

Brad,

If you go to http://www.quakertech.net/heating/heating.html

and look at the upper left of the first image, you can see the tank up there between the joists. It's hard to sort out the pipes from this angle. Here's a pic of the tank itself: