User manual DOMETIC AIRHANDLER

[. . . ] Airhandler Installation, Operation & Maintenance Manual Dometic Marine Rev. 20100818 L-2812 English PN: 0880268 www. dometicusa. com COPYRIGHT © 2007-2010 Dometic Marine. No part of this publication may be reproduced, translated, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without prior written consent by Dometic Marine. Every precaution has been taken in the preparation of this manual to ensure its accuracy. [. . . ] Because they are not ducted, they must be able to deliver air directly into the conditioned space. They must be located against the inside of a bulkhead or partition common to the space to be conditioned. The supply-air grille must have free area at least equal to the cross-sectional area of the coil (i. e. , length x width of the coil). If the Blowthrough cannot be flush mounted against the bulkhead or partition, a plenum chamber may be attached between the face of the coil and the inside of the partition. The cross-sectional area of the plenum must be equal or slightly larger than that of the coil. The plenum must be a short, straight run, and it must be completely sealed. The plenum must be insulated and have a good vapor barrier to prevent condensation. Wood is permeable to water and water vapor, and should be sealed to prevent delamination. There are four vibration isolation grommets in the top of the unit for suspension mounting. The filter and return air to a Blowthrough airhandler must be provided by a properly sized return-air grille. The filter must be located at the return-air grille, because the unit cannot accept a filter. Be sure any gaps in the return-air path are filled so that no return air can bypass the filter. · · · CIRCULATING WATER SYSTEM SERVICE VALVES Ball valves are required before and after each airhandler (see Figure 1). The ball valve for an airhandler should be ¾" full port for all airhandlers up to 24K. Figure 1: Diagram of Airhandler Piping and Service Valves HOSE Flexible, reinforced hose between the service valve and the unit will isolate vibration. Hose to an airhandler should match the hosebarb that comes with the airhandler. Each hose connection should use double/reversed stainless steel hose clamps. 8 L-2812 ENGLISH Airhandler Installation, Operation & Maintenance Manual CIRCULATING WATER SYSTEM WATER FLOW DIRECTION Note the arrows on the unit indicating direction of water flow. Reversing the flow can cause a number of problems, such as reduced performance and air lock. In general, the water usually enters low and exits high. TIGHT CONNECTIONS Always be sure to double-check connections (especially hose clamps) for correct placement and tightness. If possible, double hose clamps should be used at every hose connection for redundant protection against leaks. The hose clamp screws should be located opposite one another. AIR BLEEDERS Provision must be made to remove air from the system. Note that when air is bled from the system, water will usually be released also. Plan ahead to avoid a mess. STRAINER Strainers are mandatory in the condenser/seawater circuit AND in the circulated water circuit. [. . . ] An electrically operated water regulating valve on an individual airhandler controlled by the thermostat. This valve provides water flow through the airhandler when opened, and bypasses water flow from the supply side to the return side when closed. On airhandlers, 3-Way valves are superior to modulating valves because they provide better humidity control. AIRHANDLER: The fan coil unit that circulates air into a specific area for heating or cooling. BLEEDER PORTS: Capped ports connected to 1/4" flexible tubing located on the airhandlers for purging air from the chilled water circulation system. BTU: (British Thermal Unit) A common term used to define and measure capacity or refrigeration effect. [. . . ]