DOE-2 Reference Manual Version 2.1 - DOE2.com

PTAC with Air-to-Air Heat Pump:This type of PTAC unit provides year-round forced-air heating and cooling.This system consists of a single air-to-air heat pump. In its basic configurationthe heat pump unit consists of a compressor, a four-way valve forreversing the refrigerant flow direction, a condenser with a fan, anevaporator usually with a two-speed fan, a filter (not shown), and a thermostat.The condenser also serves as an evaporator and the evaporator alsoserves as a condenser, depending upon whether the unit is in the heating orcooling mode of operation. The unit may be specified with outside ventilationair, in which case the supply fan runs continuously rather than cycl ing withthe compressor. This PTAC has no return fan option and the supply fan isassumed to be a two-speed blowthrough fan with the fan motor located insidethe airstream. Optionally, the unit may be specified with a thermostat withnight setback.Table IV.24 shows the commands and keywords that must be entered forsimulation of this system, as well as those that are applicable but optional(i.e., program uses default value'if entry is omitted). To specify this typeof PTAC, specify HEAT-SOURCE ~ HEAT-PUMP (plus the other keywords appropriateto a heat pump, if des ired).-ITEMS SHOWN IN DASHED BOXESARE OPTIONAl.. COMPONENTSIV.101 (Revised 5/81)