Page 479 - 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

l fan convectors KEY POINT
l wall mounted
l kick space Radiator standard BS
l towel warmers EN 442
l towel warmers with integral panel radiators Radiators must now
meet the above BS
l skirting heating. EN number, which
supersedes the old
Panel radiators British Standard which

Modern panel convectors/radiators are designed to emit heat by convection was BS 3528. After years
and radiation (refer to Chapter 3, Scientific principles, to read more about this); of testing in Europe the
certification of ‘rads’ was
70 per cent of the heat is convected. They have fins (often called a convector) brought up to date to
welded to the back of the radiator, which serve to warm the cold air that passes ensure that all radiators
through them, creating warm air currents, which flow into the room. This met the minimum
dramatically improves the efficiency of the radiator. Steel radiators that do not thickness, pressure
have fins rely on radiant heat alone and this leads to cold spots in the room. tolerance, treatment and
Positioning of the radiator is, therefore, critical. Radiators should be sited on paint quality which helps
with limiting corrosion.
a clear wall with no obstructions, such as window sills, above it. If this is not Under these tests, the
possible, enough space should be left between the top of the radiator and the technical committee
obstruction to allow the warm air to circulate. responsible for the

It is recommended by radiator manufacturers that radiators should be fitted at changes use something
called Delta T (ΔT) to set
least 150 mm from finished floor level to the bottom of the radiator (depending the new standard. Delta
on the height of the skirting board), to allow air circulation. T defines the difference
between the water (delta)
Connections to radiators temperature in the
Radiator connections are classified by their abbreviations. For example: radiator and the ambient
air temperature (T) in a
l TBOE means top bottom opposite end (used on heat sink radiators with solid room. As water passes
fuel systems and one-pipe systems) from the flow and returns
l BBOE means bottom bottom opposite end (the usual method of radiator through the radiator it
connection) will give away the energy
l TBSE means top bottom same end (used with some one-pipe systems). it has obtained from the
boiler. Delta T is set to
The most common types of radiators are shown In Figure 7.37. certain data standards
to ensure that the least
amount of energy is lost
from the radiator, helping
to reduce the use of
natural resources without
reducing the radiator’s
performance.

Single Single Double Double
panel panel panel panel
single single double
convector convector convector
fins fins fins

p Figure 7.37 Types of panel radiator

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