Invisible heat domestic water systems

Efficiency is Key!

IH Aquaflex PE-RT 90 domestic water system pipeIH supply a range of water pipe and distribution manifolds and energy efficient fittings for domestic hot and cold water.  Please read the Hot Water System Efficiency section on our website which offers guidelines on pipe sizes to ensure maximum overall efficiency from your heating and hot water system.


4IH Aquaflex domestic water pipe (pipe in pipe) and manifolds are becoming extremely popular and are simple and quick to install.  They are used for all sanitary applications for hot and cold water supply; standard push-fit fitting and inserts can be used which are readily available throughout the UK.

PE-RT Pipe Test Results SKZ, KIWA/KOMO
temp pressure/bar lifespan
95ºC 11.2 5 years
70ºC 15.3 50 years

A typical water system runs at 3.5 bar at 65°C giving a life expectancy in excess of 50 years.

Pipe Dimensions

Domestic water system PE-RT pipe is available in 10mm, 12mm, 15mm, 22mm and 28mm in lengths of 50 meters.

We can also design your domestic water system and add it to your CAD drawing when you buy an underfloor heating package from IH.

Manifolds are available in sizes suited to all building requirements.

Domestic Hot Water System Design

The basic principle is that for every 28mm supply coming into a house, you can "T" off 3x22mm supplies from which you can take 3x15mm supplies from which you can take 3x10mm or 2x12mm supplies.  This will allow equal pressure throughout the house if different taps and water points are used - so there will be no pressure loss.  Think of it as the branches coming from a tree; first you have a large trunk from which large branches come off, followed by a network of smaller branches.

Speedfix fittings are used to make all connections and are available from any plumbing merchant. IH can design your system and supply you with the right pipe work, shower fittings and valves if you require.


Pipe Sizing

If you have a 3-bar supply of water coming into the house, the following (preferably plastic) pipe sizes should be used:


Pipe in Pipe

We strongly recommend that you use a modern plastic pipe in pipe system with manifolds and stop taps.  The use of plastic pipe will eliminate the sound of cavitating, rushing water which is associated with copper pipe work so it's much quieter.  Plastic pipe in pipe materials and installation is considerably cheaper than a copper pipe system - it's also less intrusive.  Typically, Aquaflex water pipe in pipe is sold in 50m lengths.