How to pipe to radiators or baseboard in basement

ewang

In the process of renovating and installing hydronic heat in my basement, which didn't have any heat prior.

For all of the other rooms (bedroom, laundry, bathroom) a single radiator or baseboard should be sufficient per load calcs, but in the family room (pictured) I think I would want a radiator/baseboard underneath each window.

The bare walls shown, I plan on framing out with 2x4 walls, with some foam insulation against the block. Question is, what is the best to plumb to the radiators/baseboard with PEX? Along the wall (Red) or coming down from the ceiling (blue)?

Required BTU at DD is about 13,000 BTU and I'd prefer to size at 140*F to ensure condensing on my new Evergreen 70. Load for the remaining rooms are about 12k BTU.

Big Ed_4

You really don't want to run a heating pipe filled with water in an outside wall . I assume your running a 3/4" pipe on a baseboard loop . For radiators you want to use diverters and risers . I would either box or bury the 3/4" pex and use 3/4x1/2x1/2 tees spaced the length of the radiator , 1/2" between the tees's and 1/2" used as the risers up into the radiators .

ewang

Thanks Big Ed_4, but what do you mean by "box or bury?

EBEBRATT-Ed

I agree with @Big Ed_4 about pipe in the ceiling and stay out of the walls as much as possible.

Box or bury means box the pipe in with something like build a soffett around the pipe....a wooden chase bury is put it inside the ceiling

If it was me I would box the pipe in and stay out of the walls and run in the ceiling. You could run both the supply and return in 1 chase and run both pipes around the room inside the baseboard enclosure (using dummy enclosure) if you don't mind the way it looks

ewang

Glad I asked, since I was sure people would tell me the walls were a no brainer!

Would a home run + manifold + TRV + PropPressureCirc be overkill? With the T's, I'm a little worried about balancing.

EBEBRATT-Ed

For just those 3 radiators with a total of 13000 btu I would make it a series loop it's all in one room and close coupled. I would run 3/4" you close to the limit of 1/2"

STEVEusaPA

Looks like a candidate for radiant in the ceiling?

hot_rod

As an example with Slantfin 30, you would need about 40- 50 feet of board at 140F. Do you have wall space for that?
Figure 145 SWT, 20 ∆, 125 RWT so average 135 temperature to size by.

Or look at some of the high output boards, or panel rads.

ewang

I'll be doing staple up with plates in the ceiling for the upstairs. And many of the rooms in the basement make it unfeasible for radiant ceiling, so I thought I would stick with baseboard/radiators for the basement floor.

ewang

hot_rod said:

As an example with Slantfin 30, you would need about 40- 50 feet of board at 140F. Do you have wall space for that?

I was planning on SlantFin at first, but was reading about the benefits of radiators and their thermal storage to prevent short cycling. With my basement load of ~23k BTU and my EG-70's 5:1 turndown, I thought radiators might be a better fit.

hot_rod

ewang said:

hot_rod said:

As an example with Slantfin 30, you would need about 40- 50 feet of board at 140F. Do you have wall space for that?

I was planning on SlantFin at first, but was reading about the benefits of radiators and their thermal storage to prevent short cycling. With my basement load of ~23k BTU and my EG-70's 5:1 turndown, I thought radiators might be a better fit.

Pros and cons to all the different type of emitters. Panel rads are also nice, a mid mass system between radiant slabs and fin tube.
Cast iron rads with TRVs, pipe exposed from ceiling? Get some brass or copper and shine it up.

If you want to operate on design days with low temperatures, you need lots of surface area on radiant emitters. Lots of baseboard, or forced convection like kick or wall heaters.

Some good formulas here for different type of emitters at low SWT
https://www.caleffi.com/sites/default/files/file/idronics_25_na.pdf

ewang

Alright, I think I got this figured out on how I'm going to pipe to the panel radiators in this situation. I read through a lot of threads on where to run piping, the dangers of freezing if pex is in an exterior wall, the issues with glycol and exhausted all options on good-looking boxed out piping chases.

I think what I'm going to do is build out a 24" wide wall inbetween the windows to act as a piping chase, that will have R15+ insulation between itself and the outdoors. Inside the chase, I'll have a tee to branch off to either panel radiator, each equipped with a TRV.


I think I like this plan the best as it gets some heat on the cold side of the room and I won't be burying any pipes in a cold, exterior wall.