Air Vents

Kirk

I am going to be replacing several airvents in a one pipe steam system ... they are older Ventor #40's from Hoffman Spec. from a bit of research it appears that it is a "one size fits all kinda vent ... with little allowance for distance from the bolier and such .. the Gortons appear to be more area specific ... any recomendations on which is a better unit and can provide more even heat distribution in a 3 story house ? ...

Kirk

Alan(CaliforniaRadiant)Forbes

From the Archives

Date: September 05, 2003 01:51 PM

Author: Fred Lobmeyer (FredL@Brencourt.com)

Subject: How do you Size Steam Main Vent?


Hi,

I am looking for information on how to size the Main Vent on a one pipe steam system. I am an amateur home tinkerer. I had fixed most of the other problems by the end of the last heating system but this one remains my last problem I hope.

The system was built in the 20s and has had some modifications. At least two different boilers. (started out life as Coal, then Oil, now Natural Gas). There have been radiators removed and the boiler location has been changed as well as all the radiators have been swapped for Baseboard Steam units against the recommendations of Dan’s books. ;-)

Unfortunately I inherited this when I purchased the house in ’97 not knowing much about steam heating systems. I am trying to resolve two problems at this point. Hi heating bills and one last radiator at the end of the Main that won’t heat.

Is there a way to calculate the actual size of the main that should be used? I know that bigger is not always better so I would rather do this the right way rather than guess and guess wrong with other consequences.

Thanks in advance for your insights!

Sincerely,

Fred


Date: September 05, 2003 02:12 PM

Author: Noel (nmurdough@slantfindotcom)

Subject: Sure is


Measure all of the pipe that the main vent serves. Not the run-outs that the radiator vents serve, just the steam main up to the vent, and the boiler piping. If you have two mains, split the common piping between the two.

2" pipe contains 0.023 cubic feet of air per foot, and other sizes have values, too. If you find out how much pipe and the sizes, we can come up with a volume of air to be vented, and a vent that will do the job.

Noel


Date: September 05, 2003 02:28 PM

Author: Jacob Myron (Dopey27177@AOL.com)

Subject: Sizing Main Vent Valves


Based on what you have described your steam heating system is a reasonablly small system.

Sizing a vent valve for a steam main in a building like yours is an excersize that is not needed.

This system is an old one and most probabley had a a master vent on the steam main. The old style vent valve had internal ports of about 3/8".

In buildings like yours operating steam pressures are a major factor.

If your system operates under 2 PSI you can use 2 Gorton # 1 vent valves. each vent valve releases 4 cubic feet of air per minute. The 2 vent valves will release a total of 8 cubic feet of air per minute.

Steam will move pretty quickly down the steam main at that venting rate.

I would not install one master vent as vent valves become defective from time to time.

Two vent valves give you a little bit of redundacy and if one vent becomes defective you still will have air released from the steam main.

The thought that bigger is better or more than a little makes for a better operation does not work in all systems.

The Gorton Vent Valve has internal 1/2" tappins or a 3/4" external tapping.

That allows you to insert the vent directlly into a 3/4" tapped T or install it into a 1/2" tapped T with a nipple.

Make sure that you elevate the vent at 6" above the steam main and about 12" in back of the drop pipe.

Jake


Date: September 05, 2003 02:41 PM

Author: Fred Lobmeyer (FredL@Brencourt.com)


Thanks for the two quick replies.

I do know that this is a low preasure system < 2lbs.

I also know that it is 2" pipe. I will get the measurements tonight and post back to the wall over the weekend.

There is currently an installed vent that I have to try and remove because it is burried in the ceiling. The current vent let out steam in the past which I know isn't good because then the furnace will never hit the High preasure shutoff thus increasing my fuel bills.

I am not sure at this point if the vent functions at all.

Again thanks for the help so far and as soon as I have more details I will post them!

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chuck_6

Air vents

Kirk:

Go with the Gorton air vents. In my opinion they are the best. You can look at the Gorton website. Also, speak to Ken Kunz at Gorton. He is terrific. Gorton's phone number is (908) 276-1323.

In addition to radiator vents, take a look at your main vents. Venting the mains will definetly help. For the radiator vents you Gorton 4s and 5s for rooms near the thermostat, Cs and Ds for rooms far from the thermostat, and 6s for those in between. Speak to Ken about main vents and radiator vents. For a relatively small investment, it will be worth it.

Chuck