VES Andover Ltd Eagle Close Chandlers Ford Ind. Est Eastleigh Hampshire SO53 4NF
Tel: 08448 15 60 60 Fax: 02380 261204 E-mail: vesltd@ves.co.uk Web: www.ves.co.uk
ecovent
NRG
Air Handling Units
Installation, Operation and Maintenance Manual
9
Continued
Steam coils are suitable for use with saturated steam up to 100psi. The pipe work must be so
arranged to provide adequate drain lines with a suitable strainer and steam trap. All steam and
drain lines should be lagged. The supply should be taken from the top of the steam main, to
avoid the introduction of moisture or air into the coil. The pipe shall be arranged so that it does
not interfere with the coil expansion. Where steam coils are fi tted it is essential that a time delay
is installed in the fan starter control circuit. The fan shall be kept running for at least two minutes
after the steam supply to the coils has been shut off, so that residual heat of the coil is dissipated.
If the pipe run is unduly long and prone to water logging, it should be properly trapped, just
before the coil.
If the steam is from a high pressure steam main, it is essential to have a working pressure relief
valve on the low side to ensure that dangerous overheating of the air and excessive pressure
cannot occur. Fitting a frost thermostat at the unit inlet and ensuring that boilers run
continuously in low ambient temperatures can prevent this.
All cooling coils have fully boxed and insulated cases, with moisture eliminators fi tted as
standard. The drain pan will require trapping to the drain line, for further information please
see
VES Ref. ID665
. DX and Condenser Coils must be connected to systems in accordance with
accepted refrigeration codes of practice and if fi tted upstream to steam or water coils, care must be
taken to ensure that the air temperature does not drop below 0°C.
For units supplied with condensing units, refer to the appropriate supporting documentation.
Installation
Coils
DX Cooling Coils
Typical DX Cooling Coil
Fig.
Typical Steam Coil
Fig.
Airfl ow
Return
Flow
4
Airfl ow
Liquid
Suction
Eliminators
Drain
Airfl ow
Return
Flow
Drain
Air vent
Typical LPHW Coil
Fig.
Steam Coils
