can i use steam rads for hot water?

ceikey

I know you guys will hate me for this, but I want to convert my steam system to hot water. I have had no luck finding a good steam pro in my area (Howell, MI) and I expect it will get harder and harder with time. Then there is the efficiency difference between steam and hot water and the government rebates I can get on a hot water boiler.

Anyways, is it possible to use the steam rads for hot water? I assume there will be some changes at the inlet and outlet that would have to be made at a minimum.

How about the piping....will it work for hot water or will it leak?

Thanks for your feedback.

Jamie Hall

No, we won't hate you...

but you may find several people, including me, thinking it's a rather bad idea.

 

In direct answer, though... the answer is... sometimes.  There are several things to consider.  The first is heat output.  A steam radiator radiates at about 215 F.  Using the same radiator on hot water, the maximum you will see is 180 F, and probably a good bit less -- and the heat output, while not exactly directly proportional, will be considerably less.  This may or may not be OK, depending on how well the radiation matches the load.  You may find yourself rather chilly.

 

Second, there is the integrity of the radiators and the pipes.  Steam operates at around 5 ounces per square inch.  Hot water operates at better than 25 pounds per square inch.  Perhaps as much as 70 or 80 times as much pressure.  Sometimes the radiators won't leak.  Often they will.  Ditto with all the piping.  Sometimes it won't leak, often it will.  You will have to find all the leaks -- slow, fast, and indifferent -- and fix them; they usually don't show up until the heat is on for a while.  "Fix" in this context means "Replace", by the way.

 

Third, there is the matter of vents.  Hot water radiators must have them, at the top of the radiator.  Usually, two pipe steam radiators don't (although I notice that yours seem to -- suggesting someone kludged the system at some time).  So you will need to tap all the radiators for vents, and install the vents (on the radiators which don't leak).  The existing vents, located where they are, won't work.

 

Fourth, there is the matter of valves and traps.  If you system has traps -- it may on the two pipe radiators -- they all have to come out.  You may or may not be able to use the existing valves, unless they have orifices or restrictions, in which case they will have to be changed out.

 

Fifth, there is the piping layout.  What works for steam probably will not work properly for hot water, so there will be extensive layout changes for the piping.  Much of this might be possible in the basement -- and would have the advantage of getting rid of the potentially leaky steam piping.  And, of course, you will have to run new returns for the one pipe radiators on your system; you may or may not have trouble getting the plugs on the one pipe radiators out so you can put the returns in.

 

The efficiency difference between a properly set up steam system (80 to 85%, usually) and a good hydronic system (85 to 90% at part load) is not enough to be a factor in choosing; it won't pay you back, even with the government rebates.



My own recommendation would be to get Dan's books and figure out how to make you steam system work properly -- it's not that hard -- and work with a good, interested plumber in your area to install a new boiler and get the steam working right.  I think you'll be happier.  However, if you decide to press ahead, I wish you the best of good fortune with your project.

Brian_74

Steam experts

If you're thinking about converting because you can't find experts, be sure to check the "find a professional" link above. If that doesn't work, check out steam trap distributors. Sometimes they have steam professionals working for them. I was surprised to find a Barnes and Jones distributor here in my relatively small town. I was even more surprised to learn that they have trained pros who work on steam systems. When I searched for your location, I found a place in Brighton, which I don't think is too far from you. The "about us" page seemed to hit all the right notes. Steam Trap Center



BTW, I'm not affiliated with these folks (or any steam company for that matter). I just found them through Google.

ceikey

OK....OK...I won't do it

I agree with all your points. I thought it would be easier, but my guess is it will be a complete replumb and I researched a little more since posting and read about the heating capacity issue also.

I will try the Steam Trap Center for a good pro. Thanks for that!

By the way what does "kludged the system" mean?

I believe there are a lot of piping issues with my system as well as rad issues (air vents, no traps). I am probably a little overwhelmed right now with all of the little issues as well as the fact I need a new boiler before the cold weather comes. So that gave me the idea to abandon steam.

Chris

Rod

Converting Steam to Hotwater

Hi- I agree with everything Jamie has said.  While it is possible to convert a steam system over to hot water, as he mentioned, there can be a lot of pitfalls. Though modern modcon hot water boiler is very efficient, it really needs to have a modern piping/pumping system utilize that efficiency.  From both a comfort and economical standpoint I think  you'd be far better off to just upgrade your steam system. There are modern, wet based, gas power burner steam boilers available that are pretty efficient, much more so than your present boiler, Just looking at your pictures I can see some changes, like properly insulating the steam pipes, that would save you a lot of fuel.



Brian mentioned a possible source for leads to steam  pros in your area. You might also try the different boiler manufacturers: Peerless, Smith, Weil Mc Lain, Slant Fin, Burnham.as they usually have a place on their website where you can enter your zip code look up their local distributor.  They should be able to give you good leads.



No matter whether you go with steam or hot water, the biggest  problem you're dealing with is finding a competent heating pro. Getting some books and reading up on the systems ahead of time will help you better understand the systems and  help qualify the person you are dealing with. There are some very good book on both steam and hydronics available in the "Shop" section of this website.  If you have any questions let us know and we'll do our best to help you.

- Rod

Steamhead

I think I remember your system

from past postings. There's a pipe coil on the basement ceiling by the stairway, right?



Not sure what your schedule is, but I'll be in Milwaukee in mid-August and again in early September. That's just on the other side of Lake Michigan, and I think Southwest services both Milwaukee and Detroit. E-mail me at steam.head@verizon.net if you think you'd like another pair of eyes on this thing.

ceikey

that's me...

Steamhead, you are spot on. I have the pipe coil. I was posting last fall when my system starting acting up. I limped through the winter, but now it is time as I know I won't make it through another winter.



I would love another set of eyes, especially with your experience! Either time would be great, but August would be better since I need to get it done before the heating season starts. I will email you for sure.

Dave in QCA

steam type or hot water type radiators?

I agree with everything else that has been said.  However, it seems that everybody might be assuming that since you have some 2-pipe radiators, that those radiators, and perhaps all of them are connected accross the top.  This is not always the case, and some 2 pipe systems, when fed at the bottom of the radiator, may have steam style radiators.  Even if you install the vent in the correct location, it will only totally vent one section of the radiator.

I have seen a large and good one pipe steam system, that was converted to forced hot water, through the design of a mechanical engineer who failed to realize that the rads were steam style.   What is amazing is that even though only the bottom 1/4 of the rad actually heated, the system did work.  (sort of)  They put in a large 2 HP base mounted pump that ran continuously, reused the very large WM boiler, etc.  Added some cast iron baseboard behind bookcases in a basement room remodel.  (did not work well at all)

Basically, the public library in this little town in SE Iowa started out with a fully functional one pipe system.  They ended up with a hodge podge of poorly thought out engineering.  I don't think they saved a penny in operating costs.

Steamhead

That sounds like

the typical government job. Take something that works well and totally screw it up, at taxpayer expense.

The Steam Whisperer (Formerly Boilerpro)

I am over that way sometimes too.....

I am often over at the Nazarene Campground for my wife's family reunion.   I'll be in Ft Wayne in a few weeks and I just came back from Hillsdale a couple weeks ago.  I am surprised you havn't found someone from Detroit.    I have been in Howell a number of times and if I remember right there's alot of hot water or steam downtown.  Contact me if you are interested in a visit...I can probably work you into some Chicago consulting stops to help keep the costs down or swing up from FT Wayne in a few weeks.

ceikey

can't wait.....

Steamhead/Boilerpro, Thanks for offering your help. I am definitely interested in keeping costs down and doing as much of the work myself as I can. Hopefully you guys are OK if I use both of your services at some point during the install since neither of you are local. It might work out where one of you are in the area when I need some help.

Anyways, I'm looking forward to getting this started now that I know I have good help!

Chris

Dave in QCA

volunteers trying to do good

Actually, can't blame it on big government.  This small town library is governed by a volunteer board of trustees.  The donate their time because they care.  I'm not sure how or why the project came to be, but it was done with the best of intentions.

A consulting engineer was involved and designed the conversion.  Johnson controls designed and installed the controls.  There is a common belief in the engineering field that steam is bad and inefficient, while hydronic is good, and efficient.  Conversion of steam to hot water is supposed to save big bucks. 

Quite honestly, I bought into the theory myself, until I found the fantastic information and knowledgeable professionals, such as Dan H. and the rest of the pros that post on this site.  Thank you all!