Size of conduit for ASHP pipes in external wall

[JIH]

I'm looking for advice on what size of conduit I should put in my external wall to take the water pipes for my, yet to be purchased ASHP.  I need to get this conduit installed before the insulation is blown but am unsure of how much room pipes plus lagging will require.

 

Many thanks.

[IanR]

How are you insulating the feed and return pipes? Difficult if you're going to try and pull lagged pipes through a conduit I would have thought.

 

You could use a pre-insulated twin 32mm pipes in a 150mm duct.

 

I've got mine from Go Geothermal ltd. (for an under-slab routing) I believe it is a Rehau product.

[JIH]

Great idea, thanks Ian. Did you bend yours? Was wondering what sort of radius you can get with it.

 

 

[IanR]

It does need a fairly generous Bend Radii. I think I was told R600 Minimum when I asked the question, But i dug my trench deep enough for an R1000.