Vertical Mains?

DTO

I'm a HO not Pro, so forgive me if this is an elementary question, but...



My one-pipe steam system has two vertical risers from the main loop in basement, each of which feeds two radiators (one on second floor and one on third floor - I think the third floor rads were added on later). There is a vent at the end of the main loop in the basement.



I am having noise issues on the third floor, and the only way I have been able to mitigate the noise is to close the radiator vents, which, of course, causes the third floor to heat more slowly (and sometimes not at all).



My question is this: Since each of the risers feeds two radiators, is it feasible (or even recommended) to put a vent at the top of the riser so that the riser will fill with steam before the rads start to fill?. I saw a post of a picture on another thread, and I was wondering if this would make it easier for me to maintain vertical (1st - 3rd floor) balance in my system.



The attachment shows what I mean. Can/should I install vents at teh marked locations before rads #2 and #4?

nicholas bonham-carter

noisy system

what sort of noise is this?

i would suggest putting extra venting on the dry returns in the basement, and gorton d's on the upper radiators. that way the steam will fill the mains more quickly, and will also rise up to the upper floors as quickly as it enters the lower radiators.

the noise may not be from lack of vertical venting, but more due to high pressure. what is your pressure in ounces?--nbc

DTO

Vertical riser vents

It is water hammer in one of the radiators on the third floor. I've been through this in another thread. I'm convinced that the rad is clogged or sagging, since it has a good deal of water sitting in the bottom when I removed it (despite being pitched at a pretty extreme angle). I'll be replacing it as soon as I can score a replacement on craigslist.



My question was motivated by the fact that there are two rads on one riser, which seems to by unusual from what I've read. Even with the vents on the 3rd floor rads open, they take a long time to heat. I was just wondering if the 2 rad/1 riser arrangement required additional venting on the risers to maximize the possibility of balancing the 3d floor with the rest of the house.

DTO

Dry Returns

BTW, I have a Hoffman #75 on dry return, and the main in the basement takes

DTO

Dry Returns

... less than 4 mins to heat to the end.

Jamie Hall

Vents

at the top of risers aren't that unusual, although not so often on smaller setups such as yours.  They do work wonders in getting the steam up to the attic!  There are a number of different ways to hook them in; depends a lot on just what fittings you have now at the top -- I'll leave that up to you -- but the location you have suggested is fine. !  I would suggest that all things considered Hoffman 75s would do very nicely.



On the noise issue check both the pitch and pipe size of the horizontal runout to the radiator.

DTO

Vents

Thanks, Jamie.



I think I will try putting vents on top of risers.



I also think pipe size may be an issue on the horizontals (and the risers, for that matter). On that topic, here is another question (I asked this on the other thread but didn't get an answer - too many other topics floating around there):



The riser that we are talking about is 1.25" up to the 2nd floor radiator, then it is reduced to 1" up to the third floor horizontal (which is also 1"). Would it cause a problem (or be any benefit) if I replaced the 1" horizontal (but not the 1" riser) with 1 1/4" (so up from basement, the riser would go 1 1/4" --> 1" --> vent --> horiz 1 1/4")?

Jamie Hall

Pipe size

Depends on the size of the radiator -- if the EDR of the radiator is less than 28, 1" should be OK, if it's pitched right (1/2" per foot).  If the radiator is bigger, 1 1/4"  or 1 1/2" would be better.