Page 511 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

Chapter 7 Central heating systems

large areas to be covered without the need for joints. Large rooms may require
more than one zone and the manufacturer’s instructions should be checked for
maximum floor coverage per zone.

Pipework installation techniques
Solid floor
There are many types of underfloor heating installation techniques for a
solid floor. Figure 7.69 shows one of the more common types using a plastic p Figure 7.67 The series pattern
grid where the underfloor heating pipe is simply walked into the pre-made laid out
castellated grooves for a precise centre-to-centre guide for the pipework using a
minimum radius bend.

The panels are laid on to pre-installed sheets of insulation to ensure a good
performance and minimal heat loss downwards. Edge insulation is required to
allow for expansion of the panels.

Tiled floor covering
p Figure 7.68 The snail pattern
Wall laid out

Edge insulation 75mm screed

Floor panel

Insulation
Solid floor plate
Underfloor heating pipes
p Figure 7.69 Solid floor underfloor heating installation

 Table 7.20 Key design and installation information: solid floor

Maximum heat output Approx. 100 W/m 2
Recommended design flow temp. 50°C
Maximum circuit length 100 m (15 mm pipe)
120 m (18 mm pipe)
Maximum coverage per circuit 12 m 2 @ 100 mm centres
22 m 2 @ 200 mm centres
30 m 2 @ 300 mm centres (18 mm pipe only)
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