To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.

The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!

In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.

dwh54
Posts: **1**Member

This discussion has been closed.

It looks like you're new here. If you want to get involved, click one of these buttons!

- 90.6K All Categories
- 72.7K THE MAIN WALL
- 1.9K A-C, Heat Pumps & Refrigeration
- 14 Biomass
- 327 Carbon Monoxide Awareness
- 2K Controls
- 631 Domestic Hot Water
- 1.8K Gas Heating
- 17 Geothermal
- 65 Indoor-Air Quality
- 8 Job Opportunities
- 1.1K Oil Heating
- 111 Plumbing
- 2.2K Radiant Heating
- 279 Solar
- 7.2K Strictly Steam

## Comments

9,104Member ✭✭✭wet steam, high fuel consumption, uneven heat, banging, water-level problems in the boiler........

Do it right. Change the header.

"Reducing our country's energy consumption, one system at a time"

Steam, Vapor & Hot-Water Heating Specialists

Oil & Gas Burner Service

Baltimore, MD (USA) and consulting anywhere.

252Member ✭u got to do what the manuf. want if u ever have problems down the road, but 8" does seem excessive. 2- 2.5" pipes don't even come close to 1- 6" flow rate, so what is it based on?

181Memberwhich makes sense for an 8" header. Must be a pretty large building...

3,196Member ✭✭✭2.5 x2.5x 3.1416x2 = 39.27

3x3x3.1416= 28.27

4x4x3.14=50.26

You need the 8" header.

cell # 413-841-6726

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

181Memberbut not sure I understand what you mean by your math. Can you explain further please?

252Member ✭this is my math, if i'm wrong i need to know where

the radius of a 2.5" pipe is 1.25" and the radius of a 6"pipe is 3"

1.25x1.25x3.14=4.90sqin + 3x3x3.14=

28.26sqin1.25x1.25x3.14=4.90sqin

=

9.8sqini can't get it to stop underlining!!! but i'm pretty sure that u add the area off the two 2.5" risers to get the tottal area of the two, but if i'm wrong and you multiply them together it's still only 24.01sqin.

181MemberThe area of (2) 5" risers is Pi*Rsquared = 3.14*2.5squared, times 2 risers = 39.27

The area of the current 6" header is PiRsquared = 3.14*3squared = 28.27, which is too small

The area of the spec'd 8" header is PiRsquared = 3.14*4squared = 50.26, which is larger than the total area of the 2 5" risers.

The minimum header size would be slightly larger than 7", which means you need an 8" header.

3,196Member ✭✭✭two 2 1/2" risers. we are in the big leagues now boys.

cell # 413-841-6726

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

4,881Member ✭✭✭✭anytime you are comparing round pipes. Squaring either D or R will give you the answer.

3,196Member ✭✭✭the actual area diffrence not ust the proportional difference. If the numbers differ by larger amounts it seems to make the problem more visible. When comparing in my head I leave out the Pi. Unless it is right after supper then I have the pie if it is there to be had.

cell # 413-841-6726

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

252Member ✭i could have swore it said " how would u size a boiler with 2.5inch risers" i thought there was a decimal point.!! you got it, whoaoawhoa, you got it!! we're in the big leagues now!

181Membermultiplying all variables by the same constant does just give you more messy math. I hadn't really ever thought about it.

I'm kind of anal though, and I think seeing the real numbers, not just proportional numbers, somehow makes me happier, whatever that means.

What about pi FOR dinner?

3,196Member ✭✭✭Pot pie or Steak and Kidney? The kidney in steak and kidney pie is beef kidney not kidney beans so you should be good.

cell # 413-841-6726

https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

181Membercan't do kidney beans... but pot pie is all good