BEST REPLACEMENT OR SOLUTION?

STEAMMING

HAVE TO REPLACE 175000BTU STEAM BOILER THAT   "COULD HAVE WON UGLY BOILER CONTEST!"

PROBLEMS; LIMITED OVERHEAD CLEARANCE FOR VENTING UNDER CURRENT CODE. OLD BOILER DOESN'T EVEN CONFORM.

BEEN LOOKING FOR CONDENSATION BOILER IF I HAVE TO BUT NOT FINDING MUCH.

FIRST PLUMMER RECOMMENDED AND I BOUGHT

Williamson Gas Steam Boiler 175,000 BTU GSA-175-N-SP HIGH EFFICENCY BUT NOT CONDENSATING AS I THOUGHT.

BUT HE HAS NOW BALKED AT DOING THE JOB.

ANOTHER PLUMMER HAS LOOKED BUT SEEMS TO BE BACKING OUT AS WELL.VENTING SEEMS TO BE THE ISSUE.

MAYBE DIG OUT BASEMENT FLOOR DOWN 2 FEET OR SO, ROCK IT WITH DRAIN SET INTO CONCRETE TO CREATE ROOM FOR PROPER SLOPE? 

ANY SUGGESTIONS?

Jean-David Beyer

LOOKING FOR CONDENSATION BOILER

Do they make condensing steam boilers? Seems unlikely to this non-professional.

Polycarp

condensing

I hear rumors that there are condensing steam boilers available on a limited basis or available soon, but I have not been able to find one .. and I just finished researching equipment for a code standard.



Condensing boilers require a low return water temperature in order to work, so that pretty much eliminates steam systems.  The only way I see it happening is to use the condensing technology as part of a DHW system.

Steamhead

What exactly is the issue

not enough overhead clearance for the vent pipe? 

The Steam Whisperer (Formerly Boilerpro)

Solutions/ condensing steamers

Slantfin makes a low drafthood boiler in that size range.  So does Burnham. Burnham also makes a powervent unit in that size range.

Condensing steam boilers are only avialable right now in large industrial sizes.The various technologies used include condensing using cold feed water and cold intake air for condensing.

For smaller steam boilers, using cold intake air is not a problem (like the Dunkrik Quantum Leap boiler from several years ago) and for most two pipe systems, cold return water is also available for condensing.  Smaller commercial condensing steam boilers are in the works right now in Chicago.

Polycarp

condensing steam

You would know far better than me - I can barely wrap my head around my own small, one-pipe system - but I would think that cold return water would be a sign of something amiss.  Wouldn't it mean that the heat is being lost in the returns (since the condensate should be exiting the radiator shortly after condensation)?  And since the returns are often in spaces that you aren't actually heating, wouldn't that mean that you are just losing it? 

The Steam Whisperer (Formerly Boilerpro)

Cold return

With two pipe steam, the steam usually enters the top of the radiator making it hot from side to side.  However, as you work down the radiator the temperature drops rapidly as cool room air is drawn through the radiator.  This chills the condensation down to near room temperature.  Now on really cold days the return water may start getting hot when most of teh radiator is filled with steam, but on typical days it can be cool.  Also, a modulating burner on ther boiler with outdoor reset or indoor feedback will tend to keep the returns cools since the radiators will rarely fill more than halfway with steam.  Just like on hot water systems, oversized radiators will work to your advantage. 

STEAMMING

venting

yes , previous boiler venting is not even code now i don't think.

so this unit is at least the same height but with a proper vent on top, thereby too tall to work in to previous duct work to chimney and have proper slant.

i can only think to lower the floor somehow.

or...?

World Plumber

Condensing/Steam

Condensing and steam are physical opposites. From my understanding of physics you can't have opposite states at the same time in the same space.

 

jpf321

oh....flue venting

here in the steam forum venting almost always means air venting out of steam pipes...but you meant flue gas venting into chimney...

Steamhead

A rear-flue boiler

such as the Smith G-8, should help. This boiler can burn either oil or gas. Here's a shot of the rear of one we installed in gas trim. 

Dave in QCA

Pictures would help

Having a hard time imagining what your venting problem is.  Just how low is the clearance.  The Williamson boiler that you have already bought has a pretty darned low flue outlet.

As the pros have indicated, you are not going to find a condensing steam boiler at the present time.

Could you take some pictures of your boiler area and explain the clearance problems with a little more detail?

Charlie from wmass

Burnham makes the indedpendence

it is a side wall vented boiler wit 3" stainless steel vent pipe.

Polycarp

Thanks

Thanks Boilerpro.  The returns in my one-pipe get hot pretty quickly, and that was my only frame of reference.  Should one-pipe returns also be cool?

nicholas bonham-carter

temperature of dry returns

in a parallel-flow system, while the boiler is firing, the dry returns up to the main vents should stay hot, because they are full of steam.

in a counter-flow system the returns, such as they are, will be cooler, because they are basically unvented. 

the wet returns are of course cooler than boiling point.--nbc

The Steam Whisperer (Formerly Boilerpro)

Typically,

the returns on one pipe steam are hot because the condensate returns inside the same pipe as the steam supply until it goes down to the floor.   If you have long wet returns it may cool quite a bit before getting to the boiler.  

Polycarp

greater efficiency

So it seems like a two pipe system has the potential to be the more efficient system. 



If I'm reading you right, a one-pipe's return water is only too hot for a condensing boiler because it is stealing that heat from the steam.  Since it is returning to the boiler hot, that stolen energy isn't entirely wasted, since it means the boiler doesn't have to work as hard to make steam.   However, if the condensate is cold enough for a condensing boiler, then it is because it has lost the heat in the wet returns, which means that it was probably wasted.  So the only way to gain the energy efficiency of a condensing boiler in a one-pipe system is to lose energy efficiency in the pipes through wasted heat.



But in a two-pipe system, the condensate can lose its heat in the radiator itself.  This means that the energy isn't wasted, since it is being lost in the room that is being heated.  But the condensate can still be cold enough to make use of a condensing boiler.



I guess you could still use a condensing boiler on a one-pipe system if you integrated DHW.  You could either use the condensing technology as a DHW pre-heater instead of on the return condensate, or cool the condensate by putting it through a heat exchanger as a pre-heater for the DHW.

The Steam Whisperer (Formerly Boilerpro)

Don't forget

The combustion air preheating.  This added 5% efficiency to the Dumnkirk boilers.

I typically get an exhaust temp on my Quamtum Leap boiler about 10 to 15F below the return water temp.