panel radiator rough-in for new construction

roundrightfarm

I will be installing a TRV controlled panel radiator and would appreciate some advice from someone with experience on doing the rough in. I will be using a Buderus radiator with inlet and outlet on the same side. I am trying to decide if I should go though the floor or the wall with my piping.

I have been often advised not to put plumbing supply lines in exterior walls, but this is the best place to put a radiator. Coming through the floor would offer more insulative protection since it avoids an exterior wall, but going through the wall would be a cleaner looking install and make cleaning the floor easier. Since the wall piping could be on the interior of the fiberglass insluation, and since it is a pipe for heat, is it really a problem to briefly go in an exterior wall? we do sometimes see minus 20F in winter.

In either case, I am also wondering the best way to terminate a pex/al/pex line for the rough in. Is it good to transistion to copper so that a rigid pipe is there for the drywallers or is pex/al/pex commonly left exposed in the room. If so, is sunlight exposure a problem here?

kcopp

Go through the floor.
Much cleaner and less issues.
They make covers for the piping.
I actually just run pex directly to the rads.
Unless the windows are open I cant see UV being an issue here.

4Johnpipe

We have installed both ways. Buderus makes a angled or straight connection also as a bypass valve. The covers look sweet so run Pex direct to connection just order the matching connectors.

4Johnpipe

4Johnpipe

Ironman

With -20* temps, there's no way I'd put those pipes in the outside walls. What if the power went out for days? Go up through the floor: it's much easier.

A note: do NOT use the standard R20 1/2" pex connectors that Buderus offers with pex-al-pex; they will leak. Get the connectors made for pex-al- pex that have O rings on the barb. Roth offers them. Part # 2347002331 for 1/2".

roundrightfarm

With -20* temps, there's no way I'd put those pipes in the outside walls. What if the power went out for days? Go up through the floor: it's much easier.

We are fairly rural and do lose power regularly, sometimes for days at a time. This means we are ready to go with generators to run essentials. I suppose if the boiler failed and could not be repaired for several days, we could still run cool water to prevent freezing, but a longer term pump failure could leave us in danger of frozen pipes. Although this would be easier to remedy in an emergency situation. Any one else have a thought on whether through the wall in our situation is a good idea or not?

If we do go through the wall, any recommendations on a stub out connection setup (pex/al/pex or copper) that has a sharper 90 turn, allowing me to stay farther out of the middle of the wall than what happens with a typical copper stub out elbow? We have 5.5" of insulation, and if the pipe would stay inside all of it, I imagine it could help a lot.

GW

If you're clear with your customers that there is a added risk, and you have 2x6, I'd run in the wall. When power goes out or heat goes down, something will freeze at some point, so freezing is somewhat on a non issue. Yes, the pipes in the wall will be a weak link. Yes yes yes.

If it were my job I'd up sell some spray foam in the piping area. Just run a 2x6 horizontally 6" above the stub outs, and foam that "box". Keep you pipes as close to sheet rock as possible.

I'm with you, through the floor look ok. Piped to the wall is sweet and super clean,.

Put the responsibility on the ho, "if house goes below (fill in the blank ) degrees, piping in walls will be at risk of freezing, ABC heating will not accept responsibility for frozen pipes.

If you're in the business of guaranteeing you will always keep someone's house warm, then maybe go through the floor.

Gary

bmwpowere36m3

Mine are on exterior walls... ran copper stubs thru floor and 3/8" PEX-AL-PEX in basement to manifold.

Copper looks nice and it's tucked in... Can't see it being a big issue. No more than baseboard or a big CI rad. Buderus supplies white PVC trim for the piping.

bmwpowere36m3

I don't think it's worth the risk in an exterior wall... granted it looks sleeker. But looks good thru the floor as well.

Mark Eatherton

I'd go through the floor, and transition to copper before coming through floor. Vacuum cleaners, kids and PEX-AL-PEX don't play well together... They make a plastic clamp around finish trim piece to clean up the penetrations. Holes are too close to use conventional chrome escucheons to clean up the penetrations through the floor. Have also seen wooden ones made by the homeowner that worked out great as well.

Also, best to layout radiators BEFORE you drill the holes, coordinating to make certain you have good firms studs for mounting, but will miss the floor joists with the risers. It does require some forethought, but makes the job easier in the long run. BTW, with radiant panels, I have successfully installed the radiators on an INSIDE wall, and it works just fine... I've also mounted the on the ceiling Any port in a storm...

Also, Buderus has a configuration whereby numerous radiators are in series instead of all parallel. Lower fluid temps has to be taken into consideration, and you will have to incorporate their bypass feature, but it is doable.

I LOVE my radiator panels that are working on a 1 pipe venturi/diverter tee system I developed myself. Virtually silent comfort.

Enjoy!

ME

roundrightfarm

Thanks for everybody's input. I've decided to take a chance and go with in the wall. In the end I felt like a very unlikely series of events would have to happen to have the pipes actually freeze in this dwelling. Plus, I found a copper stub-out by shark bite that has a tight 90.

https://www.plumbersstock.com/cash-acme

Although it is pricey, it will make the install very easy and keep me well inside the insulation.

Also, Buderus has a configuration whereby numerous radiators are in series instead of all parallel. Lower fluid temps has to be taken into consideration, and you will have to incorporate their bypass feature, but it is doable.

How is this zoned? How do the TRVs still work properly in this situation?

GW

Nice, way to grab the bull by the horns.

I'd feel a little queezy with the mechanical connections in the wall, I'd feel better with a crimp or something more permanent. The heat sometimes will have an affect on the compression joints loosening a bit.

Mark Eatherton

Also, Buderus has a configuration whereby numerous radiators are in series instead of all parallel. Lower fluid temps has to be taken into consideration, and you will have to incorporate their bypass feature, but it is doable.
How is this zoned? How do the TRVs still work properly in this situation?

Each radiator has an external bypass. It creates a path of restriction that assures flow through the radiator if the TRV is open, and when the TRV is closed, flow bypasses this radiator and moves to the next radiator in the circuit. In design, you have to assume a lower entering water temperature, which may equate to a larger radiator, depending... It can save a significant amount of labor on the installation of S&R lines, but may require a line size greater than 1/2", again depending upon connected loads.

ME

SWEI

I still like reverse return for radiators.

jonny88

Transition to copper is great advice.I know from experience.In my case it wasn't vacuum machine it was the floor sander.Luckily we had it on a manifold so the leak was stopped quickly.

hot_rod

Here is an example of an "H" valve with bypass. You can adjust the amount of bypass, usually up to 3 rads in series.

Also a drawing that shows the 3 options for piping.

And a trim piece for the piping.