Running a baseboard loop using steam condensate return where baseboard above waterline

Joseph_4

Hi,

I'm looking to run a baseboard loop using steam condensate return where baseboard above waterline say second floor without heat exchanger. I have serviced a few and understand how to install it. (Dan has a clear diagram in back of Golden Rules of Hydronic Heating) My question is- how many have done in and have not had problems. I have a close friend plumber who installed one and it worked first year and then stopped working. i understand if any air gets in the loop it stops working.. Does anyone out there do the successfully on a consistent basis? Putting in a proper Everhot heat exchanger which i have done a few times is cost prohibitive for someone who wants to add one or 2 pieces of baseboard.

I dont like to do jobs where cant gaurantee results to customer

Thanks

Joe

Jamie Hall

Are you planning on using the condensate returning to the boiler, or are you planning to circulate the hot water from the boiler with a pump?

The former approach — using "hot" condensate — isn't going to work. There simply isn't enough of it to make any significant difference. Let's say — just to make the arithmetic easy — that you are going to use the condensate from a total of 34,000 BTUh of radiation (an EDR of 140). That will give you a grand total of about 4.5 gallons of condensate — per hour. About half a pint per minute.

You're not going to get much heat out of that…

The second approach does work. You need a circulating pump, of course, and a thermostat to tell the pump to run and an aquastat to keep the boiler warm enough to be useful, but it does work, and work well. You may have problems with air in the loop, unless the pump you select has enough beef to raise the water to the second floor — typically let's say 15 feet. Some but by no means all circulators do. Once the thing is primed — purged — it will stay that way, though, so you can use a more normal circulator — provided it stays primed, which means your pipe work is very well done indeed.

Danny Scully

You’re going to pipe it all in copper @Joseph_4?

EBEBRATT-Ed

It's just like sucking water through a straw. You hold your tung on the straw it stays full of water.

You pipe it all in copper, no air vents and pipe it like Dan says and it will work has to be leak free.

How high up are you going? I think two stories is the limit. You only need a normal pump although a bronze pump is recommended. It acts like a closed loop so just size the pump as you would for any closed loop.

Keep the pipe size down. If your 15,000 btu or less use 1/2",

Mad Dog_2

It's the Poor man's HW loop, but it will work..

1. Keep your Flowchecks and purges as low as possible.
2. Make sure you draw & return from tappings that take the longest path THROUGH the boiler sections.
3. No air vents
4. Use ball valves & install tees on both sides of them w boiler drains.
5. Charge & purge all the air with a seperate water source like the drain off the HWH or a spigot.

As long as you don't drain the boiler and returns all the way down, the vacuum will hold for years..

Mad Dog

Joseph_4

if needs to be copper will do in copper.. is there any problem using propess fittings?

thx

Joe

EBEBRATT-Ed

If you trust PP to be leak free. At the top of the system you can have a vacuum. Not sure if PP is good for that

Joseph_4

have been using for 10 years 99 percent time they dont leak

thx

joe

ethicalpaul

All this talk of leaks and pipe sizes and materials is moot. @Jamie Hall had it right, even showing the math — there's not enough mass of hot water from steam condensate to heat anything (in residential applications).

the little heat there is will barely heat the pipes let alone a convector…how long is a typical call for heat? There is no condensate until the steam is running, don't forget to subtract that time. Those return pipes will be room temperature, get heated by a tiny amount of 190 degree water for a few minutes, then that's it until the next call for heat.

STEAM DOCTOR

@ethicalpaul think that Joseph wants to run a hot water loop using the boiler water. Not the returning condensate. Probably should have written the original post a little bit better.

ethicalpaul

Oh thanks, you are probably right. I blame my reading comprehension. Here is the article to read, @Joseph_4:

https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

I installed a hot water loop on my steam boiler. Some boilers make it easier than others, but it's always possible. Peerless is the easiest because they give you extra ports specifically for this purpose. Mine pulls water from the boiler, circulates it, and returns it to the condensate return.

The system can go above the water line if you want. They say you shouldn't use a cast iron circulator, but I did and if you raise the PH of your water to prevent corrosion, you should be fine. Mine is 3 seasons old with no trouble yet. I do have a screen wye filter on it. No heat exchanger. I bought an aquastat to keep the boiler up to temp but I don't even need it—the boiler is always hot enough during the winter to keep the loop hot.

Joseph_4

i apologize for not writing post better, am trying to run through boiler water not condensate, may return to condensate side. thank for the info and the link

Joe

pecmsg

just put a seperate heat exchanger in. Make hot water and circulate that. Easier and less issues!

EBEBRATT-Ed

@pecmsg

I agree but don't agree.

A heat exchanger, another circulator, expansion tank a pressure relief valve and a PRV for water make up is a lot of $$$$ to spend for a few feet of baseboard.

Grallert

As everyone, mostly everyone has said, It's works and is relatively simple. I've done it a few times and the only issues I had is when someone else goes to work boiler and doesn't understand the loop. Once the siphon is broken you have to start over. But it works and works well in my experience.