Underfloor heat pipe specification and pipe centres and radius bends.

[Paul GG]

In my attempt to future proof my underfloor heating design to maximise the heat output at the lowest possible mean water temperature, I am planning pipe 16mm dia pipe centres at 133mm governed by the nature of the installation (3 pipes per space between floor supports at 400 mm ctrs. - Serpentine layout.
I would welcome any advice on the best possible pipe spec or brand for this approach so alleviate any issues with bend radius on the pipe.

My second option is to move to a 200mm pipe centre layout scenario ( 2 pipe per space between floor support at 400 mm ctrs. Again any advice on the best possible pipe spec or brand would be appreciated.

The concluding question is the heat output gain via 133mm pipe centres again 200mm pipe centres ,at the same mean water temperature is difficult to calculate ref differing floor constructions . Maybe the simple answer here is to raise the mean water temperature a few degrees under the 200mm pipe centre option to achieve same output of the 133mm pipe centre option.

hope all this make sense , and any advice from practical experience would be much appreciated.

 

[Ben-gee]

You talk about floor supports, what are they and what are their dimensions?
400 centres does not give 400mm between supports unless they have zero thickness!

 

[Paul Griffin]

Sorry , the floor supports are 50mm wide ( 350mm space between supports) some like the photo attached. The plywood on top of the floor joists as per the photo would a cement board to improve heat efficiency ( heat sink)

 

[ShaunCorbs]

Smaller centres = lower heat input temp
Bigger centres = higher heat input temp

 

[fowlerboi]

Have fitted a vast amount of differing systems and all 15/16mm pipes I've ever used have a rough bend radius of 200mm. If you were to go down the route of 130mm centers you would need to stagger to bends to form a sort of bell shaped turn.

 

[Paul Griffin]

You talk about floor supports, what are they and what are their dimensions?
400 centres does not give 400mm between supports unless they have zero thickness!

Sorry , the floor supports are 50mm wide ( 350mm space between supports) some like the photo attached on original thread . The plywood on top of the floor joists as per the photo would a cement board to improve heat efficiency ( heat sink)

Attachments​

 

[Paul Griffin]

Smaller centres = lower heat input temp
Bigger centres = higher heat input temp

Thanks Shaun, any advice on pipe spec in relation of achieve the bend radius with ease without any possibility of kinks etc. thanks

 

[ShaunCorbs]

Thanks Shaun, any advice on pipe spec in relation of achieve the bend radius with ease without any possibility of kinks etc. thanks

You can do 120mm centres easily with mlcp you can do 100mm centres with a bending spring / bender