What is Wirsbo 20?
Wirsbo 20 Underfloor Heating is a complete radiant heating
system incorporating a 20mm diameter flexible plastic pipe
produced in cross linked polyethylene (PEX) and an extensive
range of water and temperature controls for maximum comfort
and fuel efficiency. (Back to top)
Choose Wirsbo UFH?
Wirsbo developed the unique method of producing its PEX piping in 1972 and
was the first UFH system in the UK to be awarded the BBA certification.
Manufactured in Sweden to the strictest international standards
including ISO9001 Quality Control Standard, and environmental
certification EN ISO14001. The pipe has also been assured
as compliant with UK Water Regulations by KIWA (Back
Wirsbo Systems are an integral brand within the Uponor Group trading in the UK
through Uponor Housing Solutions. With hundreds of years of
unbroken company history Wirsbo lead in modern warm and cooled
water systems design. Wirsbo continues to develop pioneering
technology for plastic pipe underfloor and plumbing systems.
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select a 20mm pipe system?
Wirsbo uses a 200mm pe-PEX pipe to enable the system to
be designed at 7.5 degree drop across the heating loops. This
minimises temperature differences in the floor and generally
means a simple serpentine installation pattern can be used
- making it easier to install. The Wirsbo system is typically
designed so that pipes are at distances of 300mm - less pipe
means the system is quicker to install and costs less. (Back
Wirsbo 20 reliable?
Wirsbo have had their plastic pipes both under continuous
test and in use for 30 years. Wirsbo hold the world record
for durability under high temperatures and pressure. The Agrément
certificate for the Wirsbo PEX pipe gives a minimum operating
life expectancy of 60 years.(Back
floor constructions are suitable?
Most new build and refurbishment floor structures are suitable
for Wirsbo 20 UFH including concrete or screeded floors; timber
suspended floors and 'floating' floors. A very wide range
of floor finishes can be used with Wirsbo 20 UFH such as Laminated
or natural timber; stone; slate; marble; quarry tiles; vinyl;
linoleum or carpet. Dense or thick carpet underlay may restrict
heat output from the floor. For more information about floor
constructions click here (Back
Guarantee does Uponor Housing Solutions offer?
Uponor Housing solutions Ltd ("Uponor") guarantees (to the original purchaser/customer)
that the pipes and fittings sold by it are free of defects
in materials or manufacture under normal conditions of use
for a period of 25 years and in case of electrical and mechanical
products for 1 year from the date of installation. (Back
type of insulation is required?
It is essential that floors which are ground bearing or suspended over an
un-heated space with or without underfloor heating are properly
insulated to meet the U-values requirements as stated in the
Building Regulations Part L1/L2 2002. The value is currently
set at 0.25 W/m2K. The thickness of insulation required to
achieve this will vary according to the type of floor, size
of floor and type of insulation selected. Generally, an insulation
with a high thermal resistance is preferable, to reduce the
build height of the total floor construction. (Back
Size & Heat Outputs
Boilers are normally sized according
to heat load requirement from the heat loss calculation in
the normal way and also taking account of other requirements
such as domestic hot water. As a guide, the heat output available
from a Wirsbo UFH system is 100W/m˛ for a solid floor and
70W/m˛ for a timber suspended or floating floor. (Back
type of boiler / type of fuel can be used?
Generally any type of boiler or any type of fuel can be used
as a heat source. Condensing boilers are certainly worth considering
because the low return water temperature often means that
the boiler operates in condensing mode. (Note: oil fired boilers
may not be suitable where there is a low heat output requirement)
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it suitable for wooden floors?
In Sweden, Wirsbo’s home country, timber floors are extremely popular
and are increasing in popularity in our country. Chipboard
floors which form the base for carpet or vinyl finishes can
be used without special consideration due to the stability
of their construction. Similarly, laminated strips or boards
are designed to be unaffected by shrinkage due to moisture
changes. Real wood finishes, however, are natural materials
and may be subject to shrinkage or expansion as the moisture
content of the wood changes. The use of underfloor heating
need not cause problems providing wood with moisture content
below 10% is selected and correctly stored before use. A marginal
change in gapping between boards may be evident between the
heating season and when the heating is not in use.
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all types of vinyl, carpet and underlay okay?
These materials can be laid over screeded or timber covered floors. Maximum
floor temperatures for vinyl type materials can be limited
to those recommended by the manufacturer but a lower heat
output may result. When selecting underlays for carpets, bear
in mind that the use of dense or very thick underlays may
also restrict the heat output from the floor.(Back
type of screed is required? What thickness?
There is no special requirement for the screed. For domestic applications,
use a fine sand / cement mix (to BS 8204) with a minimum thickness
of 65mm. Wirsbo recommends that wherever possible the thickness
of the screed is 75mm. No special screed additives are necessary.
Anhydryite screeds and other types of flow screeds will not
have an adverse effect on the pipe. However, it is very important
that you advise us if you have this type of screed in your
project. (Back to top)
the pipe affected by heating system additives?
Normal additives, such as Fernox and Senitel, will not affect the
pipe. The integral oxygen diffusion barrier on the Wirsbo-pePEX
pipe limits oxygen permeation through the pipe wall to help
prevent oxidation of metal components in the system. This
helps to reduce maintenance costs. (Back
I be warm enough?
building meets minimum insulation standards as laid down by
current Building Regulations, Wirsbo UFH will provide full
comfort conditions. Floor temperatures will not normally exceed
29°C which means that the floor will feel comfortable.
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it expensive to buy / run?
It is a competitively priced system when compared to good
quality or special radiators (such as a Low Surface Temperature
Radiator), used in certain applications. Independent tests
carried out on operating efficiencies suggest that UFH can
be up to 26% more efficient than radiators. (Back
happens if the pipe gets damaged?
If the Wirsbo-pePEX pipe is damaged, it can be restored to
its original state by carefully applying heat from a hot air
gun to regain the original dimensions. If the pipe is punctured
it can be replaced, if accessible, or repaired using a high
integrity pipe repair coupling available from Wirsbo. (Back
Wirsbo-pePEX pipe is perfectly safe. It is non-toxic and can operate at
temperatures as low as -100oC to over +100oC and pressures
up to 10 bar (approximately 145psi).
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