Newbie Venting Question.

Toymotorhead

I have a parallel flow steam setup in my house, with returns that only drop when they get back to the boiler. I have two loops, one with 55 feet of 2 ½ pipe on the mains , which then drops a few inches via a pair of reducing elbows down to a 1 inch, and has about 10 more feet of 1 inch piping before it turns and drops back to the boiler. This loop drives 7 radiators in the main part of the house.



The  second loop which is 45 feet of 1 inch pipe out, and then drops into a 45 foot return in ¾ pipe. This second loop only drives one small radiator on a riser in the upstairs bathroom.



Both loops have a tee with a 3/4 NPT tap about a foot before it drops vertically to back down to the boiler. When I bought this house both of those vents were completely blocked, and were replaced with home depots finest ‘main line vents’ which through some reading around here, and some thinking while staring at my boiler are almost worthless.



So the question is what would you guys recommend to replace those main line vents given the size of the runs. If I am understanding things correctly anything venting wise would be an improvement. The larger main takes a long time to heat.



I am thinking to start with a Gorton no.2 on the big run and a Gorton no.1 on the smaller one? The current system works, but I know it is a system that could work a lot better then it does with a little tinkering.



Thanks

Richard.

RDSTEAM

Vents

Well, if you go with a Gorton #1 venting at .330 cfm @1 oz of pressure on the smaller line and a Gorton #2 venting at 1.1 cfm @1oz of pressure, the main lines should heat up in less than 2 minutes and within a decent amount of time from each other. Your larger line consists of 1.65 cubic feet just in your 2.5" piping and your smaller 1" line contains somewhere in the .31-.32 range. You should fair well with your idea of a #1 and #2, be careful because the #2's are quite big. Make sure you have the cieling height. Also make sure your rad vents are in tip top shape, if those aren't venting, then replacing main vents are a mute point.

Rod

Info on Venting

Hi Richard -   

      For information on venting, you might want to take a look at Gerry Gill’s website as it has a lot of information on steam heating. 

http://www.gwgillplumbingandheating.com/



 Gerry Gill is a very experienced Cleveland steam pro and he and Steve Pajek wrote a great book on venting which is available in the Shop section of the Heating Help website.

http://www.heatinghelp.com/products/Steam-Heating-Books/25/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

The venting tables from his book are also included in the book- “Greening Steam”.

 -Rod

http://www.heatinghelp.com/products/Steam-Heating-Books/25/158/Greening-Steam-br-How-to-Bring-19th-Century-Heating-Systems-into-the-21st-Century-i-and-save-lots-of-green-i

Toymotorhead

Thank you

Ok it sounds like I am on the right track.  How tall are those Gorton no.2's anyway? I think I have almost 20 inches above that take off. So I think I am good.



2 minutes to get steam through the mains, wow. That is a pretty big reduction from the 10 minutes on the smaller on and the 20 minutes on the larger one that I was seeing last year.



Time to get my orders in.



Thanks

Richard.

RDSTEAM

20" is more than enough

Im not 100% sure how tall they are, but i believe just under 7"