How will a PEX run on an outside wall fare in a Northeast winter?

[Lee_Leses]

I'm getting ready to finally move my washer and dryer up to the second floor, and I'm having some second thoughts about the water hook ups. This is a brick row house and what I have is a cold and a hot run of pex going up two stories from the basement and it's on an outside wall. As I think about it, it's been my experience that brick is very porous and the air kind of goes right through it, probably more so than an outside wall that's built with plywood or particle board with insulation in it. I can add insulation to the part of the job that is this closet on the outside wall. The main wall was insulated but in the closet where all the piping and drain work is coming up and the exhaust for the dryer so far I haven't finished it with any kind of insulation. On the first floor all the pipes are going upstairs in the small coat closet by the front door. I just added an outside picture for some reference! I was thinking about maybe quarter inch foam right up against the cinder block as an air barrier and then maybe some insulation in front of that. Depending on how I insulated, what is the thinking out there about whether pex can withstand single-digit temperatures in the winter without bursting? I would be OK with it freezing, I just want to know if the pex could withstand the cold without bursting like copper probably would. This is in PA, so usually the danger months would be January and February.

Lastly I'm wondering if there's any kind of recirculation pumps or some type of pipe heaters or something I'm not thinking of that could keep the bay with the pex warmed up in the winter months when the temperatures are below freezing? I hear pipe heaters can be pretty dangerous too?

Any and all ideas would be appreciated!

 

[Reach4]

Are you saying there is no insulation in your outside wall?

 

[Sponsor]

 

[Lee_Leses]

The entire front wall now has 4" studs with bays filled with 1/4" foam as an air barrier and then 4" of fiberglass.

However -- so far the 1st floor closet and 2nd floor closet have nothing except I started to add a little foam. I'm thinking of adding thicker foam board in the closets, for starters.

 

[JohnCT]

You don't ever want any pipe to freeze, even if it can survive it.

You want your pipe outside of the outside wall (in other words, you want it in the living area) in colder climates.

No matter how well insulated the outside wall is, cold air will eventually cool the air trapped in the wall, so you want your pipes inside of the insulation with airflow around it.

For instance, if you have pipes running through your attic, you want to *remove* the insulation between the pipe and the living area and insulate above the pipe facing the attic cold side.

John

 

[Lee_Leses]

Thank you JohnCT you're 100% right!

The place I need to beef up the most is the small 1st floor closet.

I wonder if I should redesign the pex pipes to be easy to drain in super cold weather?

 

[Fitter30]

Run both water and drain inside the room. Insulation just slows transter of heat down.What are you doing with the drier vent pipe?

 

[Lee_Leses]

I framed behind the dryer using metal, and behind the 1/4" foam air barrier is cinderblock.

I'll make as much of the duct run as possible using smooth duct with the seams sealed with HVAC foil tape, no screws into the duct to snag lint. I'm thinking of using aluminum flex duct to connect at the floor to the dryer.