Horizontal Run Out EDR

MikeyB

Have a 1" horizontal run out off a 2" main that serves a 1" vertical riser (not dripped) and has (2) radiators connected to the 1" riser (2nd floor & attic) the EDR for the radiators are 14.4 & 15.75 = 30.15 edr. In TLAOSH on page 89 theres the chart for the max EDR for a 1" run out when the riser is not dripped and it reads 28 EDR, now since i am exceeding the EDR rating with just the 2 radiators alone and not including the piping can i drip (and run this wet return back to the boiler) the riser without increasing the horizontal run out to 1 1/4"? This way would be  easier than cutting the 2" x 1"  tee out and trying to get a 2 x 1 1/4" tee in the main. Both of the radiators connected to this riser always took a long time to get hot. Thanks guys

gerry gill

My gut instict

is telling me that you have other issues beside that load on the riser..i have a chart from 1919 that says 30 edr on a 1'' riser..charts arn't cut in stone..have you tried balancing?

MikeyB

Balancing

Thanks Gerry, I was first thinking of installing a vent on the top of that riser and try to balance out the system as well (before adding a drip), there are some main vent issues i have to address along with a couple of other radiators as well. This attic radiator on the top of that riser was installed by my Dad and uncle many years ago in my uncles house, originally there was just the 2nd floor radiator on that riser, and they just removed the old rad valve and installed a tee then continued the 1" up to the attic and re-connected the 2nd fl rad. I noticed when i was looking through the system a couple of weeks ago when running the boiler to see if there was any hammering, water line issues etc, i noticed that  an valve was installed on the 1" runout to that riser. I never saw that before

Steamhead

What type of valve?

if it's a globe or stop valve, that might be your problem.

MikeyB

Valve

Sorry about that Steamhead, theres an air vent on that runout, my Aunts brother put it in, so im thinking that riser had problems for a long time.

j a_2

resize

Hello,   Why not do a heat loss, and you may find the rads are over sized..That way just simply replace them with the corrected size, assuming they are over sized, as most are nowadays, due to new windows and insulation..Take a real good look at any work done after the original installation, funny what you find, out here...The charts provided in Dans book are dead on..........Get the greening of steam book I am sure you will find a simple answer....Do not over think   JA

MikeyB

EDR

Thanks ja, the heatloss is very close to the EDR ratings of the existing radiators on that riser, the existing boiler  replaced the old oil conversion boiler about 35-40 years ago by my old bosses old boss, my Aunt say the attic radiator never really gets hot, if i can get both of those radiators hot by installing some risers vents on the top and vent the 2 radiators independently it will be alot less work then trying to drip that riser. There are some definite venting issues that need attention as well (2- mains and some rads that dont heat well), so i think ill break out Gerry and Steve's venting chart and start working on that. Anything im missing guys?

Steamhead

First thing to try

is to move the runout vent to or near the top of the riser.



If that doesn't work, dripping the heel of the riser as you described earlier will increase its capacity.

MikeyB

Venting

Thats what im going to do, thanks again guys for the advice