ERV
HE2XRT
RENEWAIRE.COM
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
1.800.627.4499
14
START-UP & OPERATION
PRINCIPAL OF OPERATION
The HE2XRT has one basic purpose: to exhaust
air from a structure and bring in fresh air from
outside, while transferring heating or cooling
energy from the exhaust air to the fresh air.
The HE2XRT is a very simple device, and will
accomplish this purpose as long as the blowers for
both airstreams are able to move air through the
energy-exchange core.
CHECKING THAT UNIT IS OPERATING
Air Flow
Airflow should be occurring in both airstreams. Sometimes the easiest place to confirm that air is moving
is at the weatherhoods.
If exact airflow is critical, it may be desirable to permanently install flow measuring stations and
manometers in the ductwork connected to the unit. These also can be used to determine when filters
should be cleaned or changed.
Use Static Taps in Doors to Measure Airflow Rates
See “Cross-Core Static Drop” in MEASURING AIRFLOW table. These may be used to directly measure
airflow in the unit.
Energy Exchange
Precise determination of installed sensible energy exchange effectiveness requires careful measurement
of temperatures and air flows in all four air streams, and in practice is somewhat difficult.
It is possible to confirm that energy is being exchanged simply by feeling the ducts. If the Fresh Air duct from
the unit into the room is closer to room temperature than to the outside temperature, energy is being recovered.
Operating Controls
A wide variety of control schemes may be selected by the engineer, installer, or owner to meet the
ventilation needs of the facility. These may include timer clocks, occupancy sensors, dehumidistats (for
cool-weather operation), carbon dioxide sensors, and others. DDC systems may also control the unit.
Most control schemes will operate the unit only when needed.
CONTINUOUS OPERATION
Continuous operation is acceptable in virtually all
conditions. Unit will not be damaged by continuous
operation as long as air flow occurs. Blower motors
may overheat if filters become completely blocked
due to lack of maintenance. Motors are thermally
protected. With continuous operation, some external
frosting may occur in very cold weather (see
OPERATION IN EXTREME COLD WEATHER).
OPERATION IN EXTREME COLD WEATHER
Unit is capable of operating at outside temperatures
down to -10°F, with indoor humidities below 40%,
without any internal frosting. Unit can operate at
more severe conditions occasionally with little or
no impact on its performance. At lower humidities,
it can operate at lower outside temperatures without
freezing the energy-exchange core.
OPERATION
