radiant slab heating pex routing questions

[Shibby021]

Hi, I live in north central MN, it can get down and stay in the negative temps for a month or 2, and I have some questions about doing my in floor heating setup before pouring concrete this friday.

most of the lines are 12" spaced from each other.

I am wondering if pex can cross over each other?

How close apart from each other should they be on the supply/return alley?

How far should the exterior perimeter pex be from the slab exterior perimeter?

I have attached 2 images, both are same design, just different background color. Not sure which appears better for each person viewing.

217 master bedroom
217 green guest room/office
224, 237, and 279 are one big open space with 279 being the kitchen
100 is utility/bathroom where the boiler/manifold will be mounted.

140,226,286, and 297 are shop area. 140 is where work bench will be, 297 is what I call a apron, where trench drain will be and where I melt the snow off snowmobiles and equipment before completely bringing them further inside the shop.

The garage door is right below 297 not on the right. the area on the right will be another insulated building with its own radiant slab heating.

Attachments​

 

[Breplum]

you might try https://forum.heatinghelp.com/ The Wall

 

[Sponsor]

 

[John Gayewski]

The lengths you have are they total lengths?

The homerun design you have is a little outdated. If you drew these and colored them according to temperatures then you'd see you have cold return water snuggled up next to your hot supply piping. Generally designers now try to go with remote headers as it increases efficiency and decreases the amount of pipe necessary by a lot.

That's all beside the point. The answer is yes pex can cross each other there is no clearance needed.

Your exterior is insulated? If so you can get pretty close to it. 10" maybe. Also I don't if windows and doors you'd change your spacing to be a little closer if possible. More tube equals more heat, right where your losing heat.

 

[Shibby021]

The numbers are the lengths for each tube.

the hottest tube is run along the exterior wall of each area.

Exterior of slab is insulated with 2" R8 HDF that is buried 24" deep vertically. Then 10mil vapor barrier is spread out and taped, then 2" R10 25psi HDF foam under the slab. Building is insulted R25 batts for wall, R60 cellouse blown for attic.

each tube will have manual valve on the manifold, however in the future, I will add smart valves.

I will rework the design with new layout for the exterior perimeter of the building, tonight after work and update this post.

 

[Shibby021]

Btw

217 master bedroom
217 green guest room/office
224, 237, and 279 are one big open space with 279 being the kitchen
100 is utility/bathroom where the boiler/manifold will be mounted.

140,226,286, and 297 are shop area. 140 is where work bench will be, 297 is what I call a apron, where trench drain will be and where I melt the snow off snowmobiles and equipment before completely bringing them further inside the shop.

The garage door is right below 297 not on the right. the area on the right will be another insulated building with its own radiant slab heating.

 

[John Gayewski]

 

[John Gayewski]

This is just an idea that I like.