Reheat Coil - Augments Vrp's Dehumidification Capability - Friedrich VRP Series Service & Parts Manual

INTRODUCTION

Reheat Coil - Augments VRP's Dehumidification Capability

Temperature differences are not the only source of discomfort in a living space. Humidity also plays a big role — especially
in climates that tend to be both hot and humid. The air conditioning industry's focus on humidity issues has elevated the
importance of dehumidification. Air conditioning units operate in environments with varying indoor humidity levels. Therefore,
the system should be able to adequately respond to the humidity changes by removing sufficient amounts of moisture in
order to keep the conditioned space within the comfort zone.
Anytime the compressor is running in air conditioning mode, it will also be pulling humidity out of the space. Fixed‑speed
systems shut off after the desired set temperature is reached (i.e. when the sensible load is met). VRP® units run much
longer at lower capacity and energy consumption than traditional systems. Humidity levels are reduced to more comfortable
levels. The dehumidification capability of VRP units is enhanced through the use of a reheat coil that provides superior
flexibility in satisfying a wide range of latent and sensible capacity demands. The reheat coil is placed behind the evaporator
coil.
At relatively high ambient temperatures, both sensible and latent components of the system capacity are required to
satisfy increased cooling and dehumidification demands. The VRP wall controller and other sensors in the unit combine to
continuously monitor the space RH levels and when there is demand for extra dehumidification, the refrigerant exiting the
condenser is rerouted to the reheat coil located behind the evaporator on the way to the indoor air stream supplied to the
conditioned space.
Thus, cooled and dehumidified air exiting the evaporator coil is reheated to desirable comfort levels for the space.
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