2 or 1 pipe - please help me decide

imike

I am replacing my boiler and pipes in the basement and have a choice of 2 or 1 pipe system (hot water).
Currently it is 2 pipes but my plumber wants to convert it to 1 pipe.

I understand that I am going to loose nice abilty to adjust baseboards separately - since they going to be on the same line within each zone.

What is your advise - is 1 pipe is better than 2 pipes ?

imike

I am replacing my boiler and pipes in the basement and have a choice of 2 or 1 pipe system (hot water).
Currently it is 2 pipes but my plumber wants to convert it to 1 pipe.

I understand that I am going to loose nice abilty to adjust baseboards separately - since they going to be on the same line within each zone.

What is your advise - is 1 pipe better than 2 pipes ?

Big Ed

Baseboard loop

You can't run too much baseboard on one loop. Large loops need to be split in two.. You loose alittle bit of heat per foot of baseboard , if it's too long you have nothing left to heat at the end ...... What was the reason for one pipe?

imike

plumber said that 2 pipe system will trap air and it will be almost impossible to get it out.

I will have 2 zones. each is about 30 feet of baseboards.
Do you think it is too long ?

Unknown

One pipe

One pipe sure takes a lot more math to get the flow rates through each convector proper, and sizing piping and circulators is critical. It makes it a lot less flexable to change later.

For instance, the distance between the tees on the main is relative to the length of baseboard and the size of the fin tube in it.

I hope he does the math.....

Noel

Unknown

Series loop can carry....

67' of 3/4 baseboard on a loop. You would be fine. Two pipe would be overkill. Monoflow would be more money.

All 3 would work, though. Venting air is simple, on all three. You choose.

Noel

Steamhead

30 feet on each zone

should be OK. But I don't see any reason to change the system. With 2-pipe, you can still get air out OK by puting a small vent on each baseboard where the return pipe connects. You may already have these vents. If the new boiler is set up to Pump Away, you shouldn't have any air problems at all.

I'd keep the 2-pipe. This would also be a good time to add thermostatic radiator valves to the baseboards in rooms you normally keep cooler than the main house, such as bedrooms. These aren't cheap, but are proven energy savers.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Big Ed

Noel

Does the max footage depends on the series ? #15 ,#30 or #80 ?

Unknown

Yes

80 series is less in 3/4" and more in bigger sizes.

The rule actually is 15,000 BTUs for 1/2" copper, 40,000 for 3/4", 80,000 for 1", etc.

Noel