- ページ 8

エア・ハンドラー Air Handlers Envirofresh SeriesのPDF 据付・操作・メンテナンス説明書をオンラインで閲覧またはダウンロードできます。Air Handlers Envirofresh Series 19 ページ。 Air handling units

ページを印刷する

ELECTRIC AIR HEATER BATTERIES

These should be wired up in accordance with I.E.E. Regulations and local by laws. It is

essential that the heater contactor is interlocked with the fan starter to prevent the heater being

energised when the fans are not running. Additionally it is recommended that a fan run on

facility is included within the controls to dissipate heat form the battery at the end of

operation. All heater batteries incorporate a safety cut-out which must be wired into the

controls system. Ensure the size of cable and contactors are suitable for load being carried. It

is not recommended for P.V.C. cable to be run into the terminal box. The cable should be

insulated with high temperature sleeving.

HEATING and COOLING COILS

General

Coils are normally designed as either cartridge arrangement where they are fitted inside the

casework of the air handling unit, or bolted directly between two sections of the AHU. All

LPHW and chilled water coils are fitted with an air vent and drain plug on the header

connections.

Drain Connections

All cooling coils include a condensate drain tray fitted with a drain connection to be

connected to an appropriate trapping system. Care must be taken to ensure that the correct

type of drain trap is used depending on positive / negative air pressure within the coil section.

Drain lines from the trap must be pitched downwards, a slope of 1 : 25 is recommended.

Installation & Maintenance of Coils

During installation care must be taken to prevent damage being caused to fins, tubes, headers

& return bends of the coil. Damage to fins can be corrected by use of a fin comb (available

from Air Handlers) all coils should be installed level and upright, unless otherwise specified.

Care must be taken to ensure the following conditions are satisfied:-

Water flow & return connections are correctly connected.



All connecting Pipework is independently supported with adequate mountings.



Any pipe movement caused by expansion or contraction must be absorbed by flexible



joints.

Coils located at high points of the system should be regularly vented, other wise coils



may become air locked causing a reduction in duty.

When connecting screwed fittings, it is necessary to restrain the back nut to avoid



damage to the coil.

Coils should be inspected every three (3) months to check for build up of foreign matter

between the fins, and that coil and connections are free from leaks. Should any foreign matter

be found cleaning should be carried out with a high pressure air line directed at the air off

face of the coil. Alternatively the coil can be washed down with a mild solution of detergent

and water, after which the coil should be thoroughly rinsed with clean water.

Eliminators should be cleaned down using a soft brush and hot water, any sediment cleared

out of drain tray and drain pipe, and if necessary repair any areas of corrosion.

Condensate Removal From Steam Coils

When air, water, or another product is heated, the temperature or heat transfer rate can

be regulated by a modulating steam pressure control valve. Since pressure and

temperature do not vary at the same rate as load, the steam trap capacity, which is

determined by the pressure differential between the trap inlet and outlet, may be

adequate at full load, but not at some lesser load.