Would this be an acceptable main vent location?

Werewolfx

My 32 unit apartment building has a 1,500,000 BTU WM boiler, one pipe steam. There are two mains, one about 400-430 feet long and the other about 380-410 feet long. The current main vents are on the four dry returns, two returns have Hoffman 75s and two have Hoffman 76's, I intend to replace them with gorton #2s, 4 to each on antlers, as we can afford them. I currently have two gorton #2s on hand, but there isn't enough room for them in the crawl space where the current vents are located, at least not yet, I'll be able to cut away an access box overhead, but not for a few months, and the ends of the mains are completely inaccessible, actually the last 200 feet of the mains are actually inaccessible. There is a riser coming off the end of one main, the east main we'll call it, it used to feed three radiators, one on the ground floor, one on the second floor in the hallway, and one on the third floor in the hallway. The ground floor and second floor radiators are still used and still get steam, but very slowly. The riser is plugged on the third floor. Could I install one of my gortons on this riser and actually benefit? It seems like it should work similarly to having it at the end of the main, and I think I can access a similar situation on the west main, to get some degree of main venting improvement until I can get time to cut away the floor over the current vents and make myself an access "box".

BobC

Venting

Adding venting can't do anything but help, in your case you have to add it where you can. Does this system feed the steam up to the top and then drop down through the floors? If so you might be able to place vents at the top of all those risers. That is just my best guess because I'm not intermittently familiar with this kind of building.



i suspect you already know this but have you gone through the calculations to see how much venting you really should have? On single pipe steam you want to vent the mains fast. Once you determine the volume of each main select your vents so they vent in 2-3 minutes. Anything greater will just burn more fuel.



Then you have to look at the volume of your radiators, and the piping that connects them to the mains, and vent them at a slower rate.



good luck



Bob

Jamie Hall

There is no reason

not to put your main vents on the end of that riser.  They won't be quite as fast as they would be right at the end of the main, due to the extra pipe involved, but assuming that the riser isn't a tiny skinny little thing, that will be a minor issue -- and it should make a world of difference.  I'd put an antler and as many Gortons as are needed for that main plus the riser right there, and be happy.  Ditto with the east main.  Comes under the heading of "run what you brung" -- just think of the risers as extra tall nipples going into the antlers!

Werewolfx

Good, sounds like I've got some venting to do. Thanks.

The building is a three story building (obviously), in an L shape, and when looking at the L as you are on the screen, the boiler is on the far right of the bottom leg, with a central hallway on the second and third floors, apartments lining each side. The risers come through the floors and in the walls of the first floor (for the most part), through the rooms on the second floor, and just through the floor into the rads on the third.

Years back, the northern most 6 apartments on the second and third floors, had most of the radiators removed and electric forced air furnaces suspended from the ceiling in the hallways, feeding those 12 apartments...today, those two furnaces spin the meters they're tied into like a tiny wheel of fortune on speed, heating the breakers they're on to over 150*, and running a $1200/month electric bill (for the whole building as well) to add to the $2000-$3000/mo gas bill for the boiler and NG 160 gallon water heater. Hoping to get that gas bill down and put the electric furnaces out of commission, only retaining them for backup..assuming I can get 9 more used radiators locally..

I haven't calculated how much venting I'll need to do, since I couldn't calculate the dry returns (which are factored in to the calculation, since the vents are so close to the boiler), as no one really knows, nor can anyone easily find out, exactly how long they are..I'm estimating the main lengths based on the size of the building on the outside, minus about 20 feet at each end. I can safely assume, it'll take more than 16 gortons, as the mains are 6", maybe 8" mains, and the risers are all 1.25" or 1.5", depending on how close it is to the boiler. Two of the dry returns are 2", and two are 1.5"..and it all gives me a headache when I start thinking $55 x 16 or higher.



Thanks for the confirmation, I've got some work to do this weekend I think.

BobC

Cost of venting

The vents aren't cheap but it is a one time expence. The savings in electricity should more than make it up and the people in those apartments shoiuld be a lot more comfortable with properly working steam heat.



Bob