Aircon 1st fix

[SuperPav]

This may be a very dim question but.... if I wanted to fit some air source wall mounted aircon/heater units in our new build at some point in the future (split system running off 1 external unit), is it possible to essentially run the refrigerant lines as part of first fix to prep for this, or are they all proprietary fittings? 

 

Growing up in a hot EU country with concrete houses, all the rooms would have refrigerant corrugated conduits cast into the concrete for this purpose, but normally only running very short/straight runs to the nearest outside walls.

 

In our case running them through internal stud walls means a conduit would be too convoluted to then be able to fish a refrigerant hose through hence the question of whether its possible to lay actual hoses down as part of first fix, and then get the end fittings put on and connected when we eventually buy and install the units?

[Mr Punter]

You may do better to work out what cooling will be required now.  Could qualify for VAT refund, but others could advise.  The electrics and condense drainage also need to be installed.  You need lots of insulation over the copper pipes.

[SuperPav]

It's a (very extensive) development of an existing dwelling, so no chance of 0% VAT unfortunately.

 

We can of course work out the cooling requirements now, but we aren't currently in a position to buy the units at this point in time, so there'd need to be an element of retrofitting. It's just how do we plan for the retrofit in advance, particularly those rooms which will be on the other end of the house from where the external heat pump will sit.

[pudding]

Yeah you can 1st fix this now, as its just plain copper tubing. Then the ends are flared to connect to the units. But, you need to know in advance exactly where on the wall the units are going and outside for the condensor unit, and where on the units the copper connects to, so you can either leave enough copper poking out or the wall and get any holes through walls in the right place. Don't need to worry right now about any cooling calcs, any units can be connected to the copper pipes, you just need to choose and manufacturer and unit to determine 15/22mm or whatever size pipes need pulling and bending. 

[PeterW]

If this is for split system then you need 8/10mm soft annealed copper refrigeration pipe which must be properly insulated using nitrile rubber insulation on both circuits if you’re burying it in walls.
 

Some split systems use smaller bore for supply and slightly larger for return so you probably would be better leaving ducts and access points available to retrofit. 

[TonyT]

And a condensate pipe and a control/power cable.