Can a radiator system be used in conjunction with the Qual-Pex underfloor heating system?
Both heating systems can run off the one
boiler provided that boiler output is sufficient. Both systems can operate
Can an inhibitor be used with Qual-PEX eg, Fernox?
Yes, inhibitors are recommended for all
heating systems, if you are not sure of any inhibitor substance please check
with Conor Manning or Paul Warren.
Can carpet, tiles and timber be used in conjunction with underfloor heating?
Yes. Any type of floor covering can be used.
Check with manufacture product details if in doubt.
Can I run an underfloor heating system off solid fuel?
Not recommended for underfloor heating as
maintaining a constant temperature is difficult.
Can pipe jointing compounds be used with Qual-PEX?
Yes. Both Boss White and Foliac compounds have
tested satisfactorily with Qual-PEX. NOTE: any other substance should be checked
with Conor Manning or Paul Warren.
Can Qual-PEX be buried in concrete?
Yes. Concrete does not have an adverse effect
on Qual-PEX and the pipe can be buried directly in concrete (subject to
Can Qual-PEX be heated?
Qual-PEX should NOT be heated with a blow -
lamp or hot air gun.
Can Qual-PEX be painted?
Yes, Qual-PEX can be painted.
Can Qual-PEX be used back at the boiler setup?
1m of copper is recommended from the boiler
and then Qual-PEX
may be used.
Can Qual-PEX be used for gas pipe or for carrying oil?
No. Qual-PEX is only guaranteed for use with
water. It should not be used to carry gas. Bord Gais only allow gas to be
carried in a metallic pipe indoors.
Can Qual-PEX be used on sealed central heating systems?
Yes, provided the maximum system service
temperature is less than 95c.
Can Red Barrier Qual-PEX pipe be used for normal plumbing applications?
Yes, provided the correct size inserts and
fittings are used e.g. 15mm
Can wooden floors be used with underfloor heating?
Yes, once the wood has been kiln dried to a
moisture level of 8%. After tile / stone, wooden floors are a better floor
covering than carpet for a good heat output. Data sheets showing the required
floor specification should be consulted.
Does Qual-PEX require lagging under floors?
Lagging is not required under intermediate floors, but should be used where Qual-PEX is run under ground floors or in unheated spaces, for frost protection and energy conservation.
How does it compare with conventional radiator systems on price?
Generally speaking, installation of a system
may cost 20-25% more than conventional systems but due to the high efficiency of
a ‘cosy home’ Underfloor Heating System, this will have a pay back period of 4-5
How long should the system be left running?
Underfloor heating systems, like conventional
systems operate more efficiently when left to run continually and controlled by
the Automix series controllers. Where time control is used, the System should
have an off period of 2 hours every 6 hours.
Is Qual-PEX approved for drinking water?
Yes, Qual-PEX is WRAS (formerly WRc) approved
Qual-PEX recommended operating parameters
The following is a guideline as to what the operating parameters of Qual-PEX are;
12 Bar 20 ºC
4 Bar 82 ºC
3 Bar 92 ºC
Short-term over load temperatures up to 114ºC
What does EVOH mean?
Ethylene Vinyl Alcohol
What effect does hard / soft water have on Qual-PEX?
None, Qual-PEX is not dissolved or corroded by
soft acidic water and the smooth bore and flexibility of Qual-PEX prevents lime
scale adhering to the inner surface of the pipe.
What is an Air Eliminator used for in Underfloor Heating Systems?
An air eliminator is used to remove the
formation of air bubbles in the system.
What is so special about the Automix 20 controller?
It is constantly adjusts the temperature of
the supply water according to the heating needs of the room which are monitored
several times every minute. This means that the room never goes above or below
temperature which makes it the most efficient control system available.
Also QPL are the exclusive Irish agent for this controller.
When taking orders for plain manifolds the following should be
- What port manifold to be used: 2/3/4 way
- What size body: 3/4’
- What size inserts: 1/2” or 15mm (or maybe 12mm one of these days!!)
What is the difference between Red and Tan Qual-PEX barrier pipe?
The only difference is the pipe size: Red is
metric (15mm) and Tan is imperial (1/2’). The pipe composition remains the
What is the guarantee of Qual-PEX barrier pipe?
What is the life expectancy of Qual-PEX pipe?
Qual-PEX is guaranteed against any material of
manufactural defect for well over 50 years.
What is the recommended longest loop length?
The maximum recommended loop length is 100m
for 15mm Qual-PEX pipe, but the optimum loop length is 75m. In cases where 150m
coils are supplied, there are always 2 or more loops to be cut from that coil. A
150m length loop should never be installed in a continuous loop. Loop lengths
are detailed on the zone list supplied.
What size pump is required for the Underfloor Heating System?
A high head domestic circulator pump e.g. WILO
What type of floor structure is required?
A screed mix application would be the most
popular ground floor method. A 90mm layer of high-density polystyrene or a 50mm
layer of polyurethane insulation is laid over th sub-floor. The fixing rail is
fixed in place approximately 1 meter apart using the holding clips. The pipe is
pushed into the grooves adhering to the pipe spacing and pattern detailed on the
zone list. Between 65mm and 100mm of a 4:1 sand cement mix is poured over the
pipework. Other installation methods may bu used and Quality Plastics should be
consulted for these.
Where should the pump be positioned?
A high head domestic circulating pump (6m-head
pump) is required at each manifold set-up (secondary pump). The pump is
positioned after the mixing valve and before the supply manifold. Please note
that there should always be a primary pump back at the boiler, and the system
must be configured to maintain a high back-end temperature.