HePex in an outside wall

Unknown

in a Levitt style ranch home on Long Island , and relocating the boiler from the kitchen to the garage . The homeowner doesn't want baseboard for heat , so we're installing 2 air handlers above the 2nd floor for both the heat and A/C .

I ran Aquapex for the hot and cold from the garage to the plumbing wall inside the home , drilling 25 floor joists 2 times - truly sucked . I'm looking to avoid that for the 4 - 3/4 inch HePex pipes to go to the air handlers . The only other option is to go up inside a new 2 by 6 outside wall . The wall is 3/4 plywood on the outside , but I'm not sure if they used rigid insulation behind the vinyl siding . I was going to insulate the pipes and get some rigid insualtion to go inside the wall , between the outside wall and the piping . Does anyone think this will be sufficient ? The wall faces south if that is a consideration . The neighbor's home is about 20 feet away on that side . Thank you very much in advance for any help .

EJW

No Ron

don't do it. It will come back to haunt you at about 2-3am next winter. Drilling is worth it, and think about this you won't need to solder 25 couplings. PS..... put a valve between the boiler feed & air scoop. EJW

Cosmo_3

I did this once.....

On an impossible job (somehow I always get these), here is what I did- I drilled big enough holes in the 2X6 wall to allow the 5/8thick pipe insulation (over the hePex) to pass through the wall intact, then I implanted a 38 degree 24v switch sensor in the insulation via 3/8" copper imbedded in the pipe insulation on the outside wall side of the pipe insulation. This pipe ended approx. 6" above the bottom of the wall floor plate, and is accessable from the basement. That was 6 yrs ago, never had a problem. The sensor switch makes @ 38 degrees, turns on the loop pump warms the pipe and turns off. I check the sensor every year by putting it in the freezer and seeing if it closes. Not perfect in my mind, but the system was on the edge of not having a big enough boiler....

Of course an even easier solution would be to use glycol


Cosmo Valavanis
Dependable PHC Inc

Unknown

That was a good idea Cosmo

I would think that the colder it gets outside , the more the fluid will travel through the piping . The only problem I can think of is the very long odds of the system breaks down and the fluid don't move for a few hours in sub zero weather . Does your sensor work the pumps even if the heat source broke down ?

The glycol is an option to consider . Do you know how it reacts with pex ? Or if it is recommended for use with air handlers ? Also , we're moving a 5+ year old Weil Mclain Gold from the kitchen to the garage . I wonder if glycol is a no-no with their neoprene O-rings ?

Thanks alot Cosmo for the good ideas .

Unknown

Ahh , those valves

I'll never get that to fly , for parts that may or may not be replaced in decades . Besides , we put isolation valves on the supply and returns . Dump a 1/2 gallon of water out of the boiler and change em on a vacuum . It's really no big deal on 2 air handler zones .

EJW

Just bustin ya

Ron a few thoughts, 1)thermostat placement 2)is there a woodstove in the house?, and is it near the t-stat area. EJW

Cosmo_3

Ron Jr.

[pumps even if the heat source broke down], I'll assume you mean the burner? Then yes, the sensor is wired parallel on the t-stat boiler enable 24v wires from the air handler to the pumop relay. So if the burner is not lighting, probably the thermostat will call before the sensor does, but either one will circulate water. As long as the pump relay has power the pumps will move water.

As far as Glycol, no problem with pex, I have not used Weil-Mclaine since they started selling boilers w/ rubber between the sections so you might want to call their tech support. Just keep in mind that you have to consider that you will lose approx 10% output from the boiler (water is a better heat transfer medium than glycol), and glycol has a higher viscosity (like 5W30 motor oil compared to SAE 30 HD for your lawn mower) and will move slower through the piping possibly requiring a bigger pump, read the glycol instructions and add the right amount, and get the homeowner to pay you to check the ph level every year with the boiler tune-up. You can go nuts and isolate the fancoil unit loop from the rest of the boiler system by using a flat plate heat exchanger to keep the glycol out of the boiler. Then remember you will need an additional water feed, airscoop, expansion tank, and relief valve for the fan coil loop side. Dan has some great books in his bookstore that I bought years ago that were great at explaining alot of this stuff, now my helper is putting more creases in the bindings.....

Cosmo Valavanis
Dependable PHC Inc

Unknown

And here I was

thinking it was a valve fetish you got . I know you were bustin my chops EJW .

There's a wood fireplace that opens to the kitchen and living room , but they will never use it ( well , unless the heat goes out I think ) . The 1st floor thermostat is in the living room .

EJW

Good points cosmo

The sensor idea is a good one but only if you have power. I to have had to glycol a system but only when I had to, not when I had a choice like Ron does now. Leave them inboard of the outside walls and sleep well on -20 nights. EJW

EJW

It seem like

over half the freeze ups I go on are from wood stoves satisfing the tstat. With the price of fuel I wouldnt say they will never use that stove. EJW

Cosmo_3

Keep in mind

Please keep in mind I live in the beautiful Lehigh Valley,PA we are 1 hr north west of philly, our lowest temp all year might hit -5 for like five minutes. If you live in the northern states and expect to see -20 alot then forget the electric gizmos and stick it to your HO's wallet for glycol system of course, sorry for the confusion... I forget how nice I have it here!

Cosmo Valavanis
Dependable PHC Inc

EJW

5 Below is Candy!

I wouldnt try it here in NH. EJW

Cosmo_3

Yeah your right

I'll never forget ice fishing up near Quebec one year, I ran out in what must have been -30 weather (without the windchill)that night to empty the #1 tank. Brrrrrrrrrrrrrrrrrrrrrrr

Cosmo Valavanis
Dependable PHC Inc