Friedrich YL24J35, Service & Parts Manual

Page: 5 / 62

TTJ-0197 (1/97) (Page 5 of 64)
APPLICATION AND SIZING
In the application and sizing of room air conditioners for cooling, it is most important to give full consideration to all
factors which may contribute to the heat loss or gain of the space to be conditioned. It is therefore necessary to make
a survey of the space to be conditioned and calculate the load requirements before a selection of the size of the
equipment needed can be made.
The load requirement may be determined very easily by simply using the standard “AHAM” Load Calculating Form,
on Page 7. This form is very easy to use and is self explanatory throughout. It is necessary only to insert the proper
measurements on the lines provided and multiply by the given factors, then add the result for the total load require-
ments.
Cooling load requirements are generally based on the cooling load for comfortable air conditioning which does not
require specific conditions of inside temperature and humidity. The load calculation form is based on outside design
temperature of 95° FDB and 75° FWB. It can be used for areas in the Continental United States having other outside
design temperatures by applying a correction factor for the particular locality as determined from the map shown on
Page 6.
When sizing a TwinTemp unit for cooling and heating, we must remember that the heating capacity of any given unit
varies directly with the outdoor ambient temperature. Also, we must keep in mind the average low temperatures
which might be experienced in the locality where the unit is to be installed. Therefore, when sizing a TwinTemp unit,
both cooling and heating requirements must be calculated. Do not oversize, or undersize, one phase of the unit’s
capacity at the expense of the other. In those cases where the unit will provide satisfactory cooling at all times but will
be inadequate for those few times that the outdoor temperature is below the maximum low for the unit, additional
auxiliary heating facilities must be provided to insure that adequate heat is available at all times.