Steam vs hydronic heating for church reno thoughts

rhodebump

This is in a former church. We have no heating in place now. I am trying to figure out if we should go with steam vs. a hydronic system.

The church had a steam system, Natural gas fired Weil-McLain model LGB-7 (input 780,000 output 631800 BTU), but the boiler was unrepairable, and the steam system only provided heating for the church, and not the basement. Each floor is about 2700 SF.

I would like the new heating system to heat the church, and the basement. There are several radiators that are extremely low in height made by "Crane". Pictures are posted. Do you think these can be converted to be hydronic?

I am leaning to hydronic heating for 2 reasons:
1) There are no radiators/venting in the basement, so we have to install pipes and radiators. Hydronic heating is way cheaper and easier to do than steam piping.
2) The steam boiler would need to be dismantled into sections to get into the building. Hydronic heaters appear to be much smaller.

I see a used LAARS Rheos Volume Water Heater/ Boiler RHCV2400NACF2EXX for sale. Would this be stupid? 1 million BTUs!

rhodebump

One more photo

Steamhead

I'd use two boilers- one steam, one hot water. That would mean you wouldn't have to modify any of the existing system, which is risky- hot water runs on a lot more pressure than steam, which WILL cause any weak spots to leak.

Also, a hot-water radiator only gives off 2/3 the amount of heat as a steam one, so there's a pretty good chance the church would not heat well if you tried a conversion. This is why we never convert steam systems to hot-water.

But before we get that far, are you certain this is steam? Let's see some pics of the boiler.

Danny Scully

Also...steam IS hydronic...mic drop

nicholas bonham-carter

What will be the intended use for the building? Will it require constant heat, or just during sporadic periods of use? Steam can bring up the temperature of a building more quickly than hot water.
From the pictures, it looks like a 2-pipe baseboard system.
Is the steam piping still in the basement?
I would restore the steam, and add a hot water loop and radiators for the basement. Measure out your baseboards and any other radiation, and post them here along with a heat loss survey for the building, for the boiler sizing. The previous boiler may well have been oversized for 2700 square feet above ground.
A steam system running at a few ounces will be a better bet than putting higher pressure hot water into the old pipes. If you have old asbestos pipe insulation, then encapsulate it, or replace with fiberglass.—NBC

Phil53

I think Steamhead might have a point about first determining if the present system is steam or hot water. The last picture of the long ci baseboard would probably indicate its hot water as most manufacturers of the cast iron baseboard recommend a maximum length of 15' when using it for a steam system.

Jamie Hall

Permit me a trivial addition -- any new boiler, steam or hot water, will be physically much smaller than the old one!

ratio

Also, I have an addition that's hot water, but feed via a steam-> water heat exchanger. Something to think about as well.

I think you'll find that it's cheaper to have a good steam guy repair the current system than convert to hot water.

rhodebump

Intended use for the building would be constant heat. We may even convert into a maker space.

Here are photos of the boiler.

rhodebump

Just in case anyone was interested, here's a page of history for the church at http://theclement.com/history/

Steamhead

Definitely steam.

Where do the return lines from those baseboards go? Are there traps in them?

Are there traditional radiators in the church? If so, how about some pics?

rhodebump

Baseboards have 1 pipe on each end, but looks like the end does not have a trap. I will get some more pictures of some other radiators. Thanks!

Jamie Hall

rhodebump said:

Baseboards have 1 pipe on each end, but looks like the end does not have a trap. I will get some more pictures of some other radiators. Thanks!

Might be an orifice system, or the return elbow might be a special fitting. Pictures please! There could also be traps on the returns below the floor -- there's no law that says they have to right at the baseboard.

mikeg2015

The gauge has a vacuum range. Wonder if its' designed to run under a natural vacuum most of the time.

I would make sure it's properly sized for radiation, get all the steam stuff working right, then add inexpensive fin tube baseboard on a hot water loop on that boiler. I would just include that in the "pick-up" factor as it's within the conditioned space overall and the basement will act more like thermal storage rather than an additional load.

Depending on the size, you might do 2 boilers if your over 300k on size. I would also add an indirect to it as well. In late spring, shut one boiler down (rotate them each year), flood both and run as hot water only, to heat the basement zone (will need heat later in the spring and early fall) and DHW.

rhodebump

@mikeg2015 Thanks for your idea. I am not 100% clear... are you saying that a single system can produce steam for the existing radiator system, and hot water for a new hot water loop? Thanks!

rhodebump

Here are some pictures of another radiator that is in the rear of the church

rhodebump

here's from the right side of the radiator above

JUGHNE

So the "church" area and basement area could be different uses/zones? It is only 2700 feet per floor?
Is the steam a 2 pipe system?

I would go for the steam boiler for the church and hot water for the basement with indirect WH if needed.

Will it need AC?

rhodebump

Yes, 2700 SF per floor, but the church has 17+ foot high ceilings. The basement has 12 foot high ceilings.

The church has an existing steam radiator system, and the basement has nothing in place yet.

I don't know what will go in here yet ... but AC is not 100% in the plan, and if we do that, i could put in a few mini-splits down the road.

I think it's a 2 pipe system. All the radiators have inlets and outlets, but i am used to seeing a trap at the end of the radiator, but I don't see any on these radiators.

nicholas bonham-carter

Looks like a trap on the radiator in the rear of the church.—NBC

rhodebump

Correction, it's a total of 3321 SF per floor. The 2700 SF was for the main sanctuary, which didn't include some space in the rear.

Walls are thick non-insulated masonry.

Ceilings are 17+ feet high. Should I double the SF to account for the high ceilings?

Trying to figure right size for the steam system.

Ironman

In your next to last pic, that's a trap. It looks like a copper Union below it and with the rad up on blocks, that would make me think that the trap(s) were added later on.

On second look, maybe it's not copper

Sailah

Cool building. I lived in Shadyside for awhile, just sold our place on S Aiken. Drove up past Tarentum often.

That's def a trap on that radiator.

What kind of Maker Space are you thinking? I was sad to hear of Tech Shop closing. I was an instructor there from day 1, taught lathe, woodshop, TIG welding and waterjet. I loved it, I would skip down there to work after my sales job in the evenings. There are a lot of people who would like a space to operate now that TS is gone and I bet those tools would go for cheap.

The Steam Whisperer

I'd complete a real heat loss calculation, measure windows doors etc and run the numbers. That building is about the same size as my home church and I think the system is only about 300,000 btu/hr for the upstairs and about 90,000 for the basement( output) There is no insulation anywhere other than the 2 inch thick exposed roof deck. If you have an attic air seal it and insulate it...you'll cut your heating load probably by about a third.
Then you can use orifice plates on the radiator supply valves to resize the radiation to the current heating load and put in a much, much smaller steam boiler with a small hot water loop for the basement off the bottom of the boiler.

Jamie Hall

In answer to the question about a hot water loop and a steam system using the same boiler -- yes, you can. Particularly simple if the hot water loop radiation is below the water level in the boiler.

Phil53

If you run a hot water loop for the basement, how much extra capacity in the boiler is needed beyond the steam load?

rhodebump

I am going to do a heat load calculation.

Yes, going for a maker space, but more of a cheaper version than tech shop. Going to be just sewing machines, drill presses, bike tools, wood working machines. I am going to market it as a "co-not-working" space, where you come and "not work" but play at hobby activities. I plan to have some old game consoles, computer game PC's.

Can any boiler support the hot water loop or is this a special feature of a boiler?

Thanks everyone! I appreciate the knowledge everyone is sharing here. BTW, the school that is part of this church had a old 2-pipe steam system with a bad boiler. I was able to find a boiler on ebay for a good deal (it was part of a ravoli company processing line in NJ) and now we have awesome steam heat in 15 classrooms!

Jamie Hall

Phil53 said:

If you run a hot water loop for the basement, how much extra capacity in the boiler is needed beyond the steam load?

Unless the hot water loop is huge in relation to the steam load, none. Most steam installations have a 33% fudge factor (also known as pickup etc. etc.) built in, which is used only when the steam system is heating up on startup, and can be used quite handily in the basement. But -- you really should do a heat load calculation.

JUGHNE

I have a church that is 5-6000 sq ft. Ceiling domes up to maybe 40'. All masonry construction (12-14" walls) with maybe 6" blown in the attic.
It has a 525,000 in/420,000 out BTUH steamer for the 1 pipe system.
The connected EDR is 1218 which needs only 388,786 BTUH with 1.33 pick up.

This will more than heat the church main floor with enough residual heat to maintain the full basement. All mains & returns insulated with 1" FG. (6500 HDD, -5 degree design area)

If the basement needs a little warming (1 to 2 times a month)there are 5 electric forced fan wall heaters.

The Steam Whisperer

Some boilers are specifically designed for a hot water loop....such as the Peerless 63/64 series. Some can be used if the right tappings are available. I would check with the boiler manufacturer for thier recommendations. On some boilers there just isn't a good place to connect a hot water loop.

rhodebump

WOW! I just "happen" to be operating a Weil McLain LGB-11 steam boiler for heating the school. I think it is a input of 1250K BTU input. I didn't even think of running a hot water loop off of that.

I am going to do a lot of measuring and report back.

rhodebump

The Weil McLain LGB-11 is in a room that is adjacent to the church and the school, however, but all the steam that this boiler makes is above any of the radiators that were part of the church boiler system.

JUGHNE

If the school had a boiler feed pump, could you pipe steam to the church basement? (it will go up or down) However the condensate would need a lift pump to return to the feed pump.

Then you might be getting into zone valves for the single boiler.
Assuming you have extra steaming capacity...1250K is a lot of heat. do you know the EDR of the school?

And with the pump in the church basement you could use steam down there also (high wall rads).

rhodebump

I do not know the EDR of the school. Should I use the building measurements to arrive at the EDR, or should I count all the radiators in the building?

JUGHNE

For steam you go by connected EDR of radiation.
Make a chart for calculations:
You need the height of each--floor to top
The columns or tubes looking from the end.
The number of sections-- as in slices of bread in a loaf.
There is info here on EDR calculations and recognizing different styles of CI.

Your EDR must currently be exceeding the school heat loss as you said the place is well heated.

rhodebump

I did some measuring tonight and used the heat loss calculator that I found online http://www.usboiler.net/heat-loss-calculator.html
Looking at a 300K boiler

rhodebump

Since it's Pennsylvania, probably a 70-80 diff would work, wchih would be 234K-266K BTU

rhodebump

any thoughts on one of these boilers? Thanks.

Burnham K5006SNEI-2 5006B
Williamson GSA-250-N-IP
Green Mountain GMGS299E 280000 BTU

nicholas bonham-carter

Did you figure the values for the radiator EDR?
The building heatloss will tell you if you have enough radiators, while the EDR from the radiator sizes will give you the boiler size in square feet of steam, which will then match up with that value found on the boiler specs.—NBC

rhodebump

Yes, we have 188K BTU from the existing radiators.

We have a heat loss of 234K for the main floor of the building.

The recommendation is to do one steam system in the basement, an Weil McClain EGH 105 (450K BTU) that will serve the basement and the church. New radiators would have to be installed in the basement three feet from the ground so that the condensate would drain.

He quoted me a number that is out of budget now, so considering other options such as a hot water boiler since I think the labor costs there would be significantly less in initial costs since we wouldn't have to worry about near boiler piping and running a lot of new steam pipes (and can just use pex).

nicholas bonham-carter

As I understand the situation, you already have the steam pipes and radiators for the upstairs, but the basement has none. You could install the steam boiler, for now heating just the upstairs, and later the basement could be heated with a hot water loop.
In a similar way, the large boiler in the other building could supply steam to the church, and hot water to the basement.
You would have to look at the difference in elevation for this as the condensate has to be returned to the boiler, using condensate pumps, and feed tanks. If the elevations had enough difference, then gravity return might work.
The controls could be tricky.—NBC