Questions on piping for new radiator - opinions welcomed

JimmyNJ

Hi everyone,

I am adding a radiator in my house and have a question on piping & venting. I am adding a 25 EDR rated radiator on the second floor. The piping path (starting in basement) will be the following:

Approximately 21 feet horizontally & 11 feet vertically.

In reading Burham's Heating Helper - do I correctly interpret that for such a long horizontal run I would need 1 1/4" piping? I understand that it needs to be pitched 1/2" per foot.

Assuming I got the piping size correct - what are people's thoughts about putting (if there is room) a vent at the end of the horizontal run so that the radiator doesn't have to vent all 32 feet or so of air in the supply piping? Needed/not needed? The Main Steam line that this takeoff would tie into is 2" and 32 feet in length and I have 2 Gordon #2's at the end of that section of main so Main venting is not an issue here. The takeoff would also be the 3rd closest to the boiler (out of a total of 8 on that section of Main) Not sure if that has any relevance.

-Jimmy

Fred

1-1/4" is recommended for a horizontal run of that length. I am assumming this is a one pipe system. 11 ft. Riser would probably be fine at 1" . What size is the valve you are using? If 1", I'd reduce the riser, in the basement, where it turns up. If the valve is 1-1/4", I personally would go 1 -1/4" all the way. Others might argue that you don't need to spend the extra money but you're not going to save huge bucks on the difference in pricing on 11 feet of pipe. Use black iron pipe, not copper and remember the valve and spud on the radiator are a matched set. If you have a new valve, use the spud that came with it on the radiator.

Bio

I added a radiator last year and it worked out good

First I'll make sure the boiler can handle the extra 25edr, also know that 2" pipe at 32 ft can handle about 90ish EDR , and if all checks out good I'll keep everything 11/4" pipe, I don't think you need to vent it, but it won't hurt to add a tee before it goes vertical
The tricky part would be pitching it back to the boiler, You may have to use two elbows with a close nipple before going vertical

JimmyNJ

Thanks for the input guys, and confirming that 1 1/4" piping is the way to go. Appreciate it.