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UNIT 4: ENVIRONMENT MANAGEMENT SYSTEMS
• Background ventilation systems such as trickle vents;
• Rapid ventilation systems such as extractor fans;
• Ducted systems including heat recovery.
Low-Energy Lighting
Low-energy lighting is easy to install and can reduce energy costs by 10-15%. Lowenergy
lamps include compact fluorescent (CLFs), fluorescent tubes, and tungsten
halogens.
CLFs last about 8 times longer than tungsten halogen lamps and use about 25%
less energy for the same light output. Tungsten halogen lamps are about 50%
more efficient than standard lamps and last twice as long. All energy-efficient
lighting offers the advantage of dimmer switches, which allow control of light
output.
Coverings and Coatings
In warmer climates, weatherproof coverings should be finished off with sunreflecting
paints to reduce solar heat gain. Similarly, pale shades used for
decorating exteriors and interiors reduce heat gain and increase light reflection.
Heat Recovery
Hospitality properties can achieve substantial savings by recovering sensible and
latent heat from kitchen, laundry and swimming-pool exhaust systems, boiler
flues, and condensed heat recovery. This heat can be channelled back for space
or water heating. Heat recovery requires the installation of heat exchangers to
separate the heat from its source (water, gas or combustion products) and transfer
it to where it can be reused – the water or space heating system. The most costeffective
heat-recovery systems for hospitality businesses are usually sensible
heat exchangers such as run-around coils and thermal wheels.
The feasibility of heat recovery depends on:
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• The temperature of the waste heat in the air or water;
• Where the waste heat is to be used, which should be closely connected
to the source of the waste heat;
• Purchasing and operating costs of the heat-exchange unit: the cost of
the heat recovered should be higher than the purchasing and operation
of the heat-exchange unit.
COMMON QUESTION What is the difference between sensible heat and latent
heat?
Sensible heat is the heat associated with a change in temperature. Latent heat
is associated with a change in state such as from liquid to gas.
Building Energy Management Systems (BEMS)
BEMS are computer-based energy-management systems which provide for the
integrated control of thermostats, boilers, and zone controllers, each zone having
its own heating, cooling and lighting units. They therefore enable different areas
of a property to be controlled separately and even shut down when not in use.