SeaMach 24 VDC
Rooftop Air Conditioners
SeaMach 24 VDC Rooftop Air Conditioner Installation Manual 5/2013
Page 3 of 20
Chapter 2 - General Information
OEM
Please make sure the Customer Envelope Package accompanies the air conditioner.
INSTALLER AND/OR DEALER
Please make sure the Customer Envelope Package is presented to the product consumer.
For more information about the contract, please review the sample contract located in the Operation and
Maintenance Instructions Booklet (Customer Envelope Package).
INQUIRIES ABOUT THE A/C UNIT
Inquiries to your Airxcel, Inc. representative or to Airxcel, Inc. pertaining to product installation should
contain both the model and serial numbers of the roof top air conditioner. All roof top air conditioning
units have model and serial number identification in two locations; (1) rating plate sticker may be viewed
by looking through the shroud louvers on the compressor side of the roof top air conditioning unit. The
rating plate sticker can be seen without removing the outer plastic shroud, (2) model/serial number sticker
(silver color) is located on the bottom of the basepan of the roof top air conditioner. If the air conditioner
is installed, the sticker may be viewed by lowering the ceiling assembly shroud.
Chapter 3 - Air Conditioning Sizing
The ability of an air conditioner to provide a comfortable environment for the consumer is dependent upon
the following conditions.
Air conditioners are rated primarily by their ability to remove heat. The thermal measurement used for
detecting a gain or loss of heat is the British Thermal Unit (BTU). One (1) BTU is the amount of heat
required to raise the temperature of one pound of water by one degree Fahrenheit. An air conditioner rated
at 13,500 BTUH can remove 13,500 BTU’s of heat in one hour.
The ability of an air conditioner to cool down a vehicle or maintain a consumer desired temperature is
dependent upon the heat gain of the vehicle. The physical size, the amount of window area, the quality
and amount of insulation, the position exposure to sunlight, the number of people using the vehicle and
the outside temperature may increase the heat gain to such an extent that the capacity of the air conditioner
is exceeded.
As a general rule, air supplied (discharge air) from the air conditioner will be 15°F to 20°F (11° C to
8.4°C) cooler than the air entering (return air) the ceiling assemblies bottom air grilles.
For example, if the air entering the air conditioner (the return air) is 80°F (26.7), the supply air (discharge
air) will be 60° to 65° F (11.1° to 18.3°C). As long as this temperature difference -15°F to 20° F (11° C to
8.4°C) is being maintained at the air conditioner, the air conditioner is operating properly.
