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Balancing A steam system

mchema Member Posts: 37

I just recently bought a 1931 colonial. Since it’s been getting cold we have had the steam heat on. The one-pipe steam heat system with a carrier boil installed in 1997 was serviced just last week. Before it was service I started researching replacing the steam vents, the tech also made the suggestions. Many are clogged and the main vents don’t even work. My question is what vent should I use. The tech really didn’t address this. He said it depends on what I want. He suggested since I was savvy to pay attention of how each room is heating and do some research on the vents. Although I told me to get some Hoffman #40 b/c they are good stand-by.

Currently my main vents are Dole #3c. The tech felt they were undersized in the first place. There are two main vents (one on each line) I was thinking of replacing them with hofmann #75 or #75H.

The second floor heats the fastest. There are a mix of Hoffman #40 and #1a. They all hiss and clank due to years of neglect.  The bedroom/bath closest to the boiler heats up the quickest. The two bedrooms furthest take longer but not as long as the first floor living room rads.

On the first floor the rad in the room with the thermostat heat the fastest (for the first floor, overall the back bedrooms on the second floor heat the fastest). But my two rads in the living room take forever… I’m  pretty sure it’s due to the air vents.  I can’t even find the company name on the vents….

My question is should I get all hoffman #40 and not worry about playing around with the adjustable vents. Or get a couple types and try them out see what I like.

I just bought Dan’s book for more info (can wait to get it!) but I’m just having a hard time picking vents and what brand…



  • Steamhead
    Steamhead Member Posts: 16,728
    For your main vents

    measure the length and diameter of each steam main. We can tell you what you need to make it work right.

    Then see how your radiators do.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    what vents for system

    i would concentrate on the main vents first. i like gorton #2's. i don't believe you can have too much main line venting. the gortons are a little less money than the hoffmans, and have 2-3 times the venting capacity. also make sure your pressure is as low as possible. under 1psi is ideal, but will be difficult to do with the standard honeywell pressuretrol. a vaporstat is better at the under 1 psi range, and if finances permit consider getting one right now, along with a low-pressure gauge [gaugestore.com, 0-24 oz.]

    after the main vents and the lower pressure have been improved, then you can check the radiator vents, and depending on conditions at that time we can advise, but i suspect they are OK. it is the main vents which do all the work, and can take lots of abuse.

    be prepared for some scrutiny from your local gas co. as you use signifigantly less fuel!--nbc
  • mchema
    mchema Member Posts: 37
    Pipe dimensions

    The main pipe is 20 foot and the diameter is 7 inches (appox).

  • Unknown
    edited October 2009
    Venting Book

    Hi Melaine-   You'll enjoy Dan's book and it will be a huge help to you.'

    You might also want to get a book by Gerry Gill & Steve Pajek,  titled  "Balancing Steam Systems Using a Vent Capacity Chart "   It gives you directions on how to go about balancing your steam system. It also lists most of the manufacturers of steam vents. It lists main vemts and radiator vents along with each manufacturer's model number and the venting capacity of ech model. That makes it very easy to compare vents and cross reference them capacity wise.

    The book is available as an E-Book that you can download (16 pages) fo I believe $10.    I have the book very useful and refer to my copy all the time.

    There is a bug in "the store " on this website so you'll have to phone when ordering .

    I have included below Dan's reply to another person's inquiry about the book which has the phone number

    - Rod

    Please call the elves

    at 800-853-8882 and they'll take care of you. One of the bugs in the

    store is that we can't bypass the automatic shipping charges at this

    point. We don't want you to pay shipping on an e-booklet. We'll get it

    fixed soon. Thanks.

    Site Administrator

    [email protected]
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