Page 510 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

The City & Guilds Textbook: Plumbing Book 1

l using individual temperature and timing controls in every zone
l multi-channel programmers allow the timing of individual rooms or multiple
zones to be set from a single point; this is often more desirable than many
individual programmers at different locations within the dwelling
l TRVs vary the heat output of individual heat emitters; this can be beneficial
where solar gain adds to the room temperature as they are very fast
reacting in most circumstances; some TRVs also have electronically timed
thermostatic heads, which can be linked to a wireless programmer.
Zoning can help make significant energy savings. It allows the optimisation
of the heating system while maintaining the dwelling at a comfortable
temperature and saving money at the same time.

Positioning components in underfloor
central heating systems

For an underfloor heating system to work effectively, the components require
careful positioning to ensure that the efficiency of the system is maintained. All
too often, systems fail to live up to their potential because of poor positioning
of key components. Key areas include:

l manifolds
l pipework arrangements (cabling)
l pipework installation techniques.

Manifolds

The longer the circuit, the more energy is needed to push the water around
it. Water will always take the line of least resistance and shorter circuits will
always be served first. In many instances, balancing the system will help even
out the circulation times so that all circuits receive the heat at the same time,
but the system will only be as good as the slowest circuit. If the longest circuit
is slow, once the system is balanced, then all circuits will be slow. In this regard,
the positioning of the manifold is of great importance. By positioning the
manifold centrally within the dwelling, the length of each circuit is balanced so
that long circuits become shorter. Even if the short circuits become longer, the
time for the heating system to reach full temperature will be shortened and
balancing the system will become much easier.

A potential problem that may occur where the manifold is located is that the
area may become a potential ‘hot spot’ on the system because of the pipework
congestion around the manifold. This can be prevented by insulating the
pipework around the manifold until the pipework enters the room it is serving.

Pipework arrangements (cabling)
There are many variations to the two basic layouts. The pattern should be set
out in accordance with the orientation and the shape of the room. Window
areas may be colder and may require the bulk of the heat in that area. Other
considerations include the type of floor construction and the floor coverings.
The pipework should be laid in one continuous length without joints. In some
instances, the pipe is delivered on a continuous drum of up to 100 m to enable
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