C L I M A T E M A S T E R W A T E R - S O U R C E H E A T P U M P S
N (ERV) Series
R e v. : 0 4 A p r i l , 2 0 1 4
4
C l i m a t e M a s t e r Wa t e r - S o u r c e H e a t P u m p s
times that of the sensible heat load and in the winter it is
a signi
fi
cant part of a humidi
fi
cation heat load.
During both the summer and winter, the ERW transfers
moisture entirely in the vapor phase. This eliminates wet
surfaces that retain dust and promote fungal growth as
well as the need for a condensate pan and drain to carry
water.
Because it is constantly rotating when in the air stream,
the ERV is always being cleaned by air,
fi
rst in one
direction then the other. Because it is always dry, dust or
other particles impinging on the surface during one half
cycle, are readily removed during the next half cycle.
During the heating season, when outdoor air
temperatures are below 15ºF, it is recommended to use
the (optional) low ambient kit (
fi
eld installed).
Low Ambient Kit is appropriate for climates with limited
HVAC system operation when outdoor temperatures are
below 10ºF.
The frost threshold is the outdoor temperature at which
frost will begin to form on the ERV wheel. For Energy
Recovery Ventilators, the frost threshold is typically below
10ºF. Frost threshold is dependent on indoor temperature
and humidify. The table shows how the frost threshold
temperatures vary depending on indoor conditions.
Because Energy Recovery Ventilators have a low frost
threshold, frost control options are not necessary in many
climates. Where outdoor temperatures may drop below
the frost threshold during the ERV operational hours,
exhaust only frost control option is available.
Low Ambient Kit (Optional)
Low Ambient Kit turns off the supply blower when outdoor
temperatures fall below the frost threshold. The exhaust
only thermostat set points are
fi
eld adjustable. Supply
fan operation is automatically restored when the exhaust
air temperature rises above the thermostat set point.
Provisions for introducing make-up air into the building
when the supply blower is off to avoid depressurization
should be considered.
FROST THRESHOLD TEMPERATURE
INDOOR RH AT 70ºF
FROST THRESHOLD
TEMPERATURE
20%
0ºF
30%
5ºF
40%
10ºF
Recovery Wheel Mode
On a thermostat call for blower operation in heating,
cooling or continuous blower, the ERW will rotate
between fresh air and exhaust air streams. Both the
fresh air and exhaust air blowers will also be operating to
overcome the air resistance of the ERV.
System Check
1. Disconnect main power.
2. Turn to “Cont” for blower operation on thermostat
controlled models.
3. Restore power to unit. Observe ERV wheel rotation
and both fresh air and exhaust air blowers will
operating.
NOTE: If Low ambient kit is used the jumper
between TB37-5 & TB37-6 should be removed.
Also if system check out is being conducted at
low ambient temperatures, technician should
be aware that this kit can cause system not to
operate.
4. Verify that the ERV (3) three phase blower motors
are phased sequentially ensuring correct rotation and
operation.
a. Disconnect power.
b. Reverse any two
fi
eld power leads to the ERV.
c. Reapply power.
5. Verify that both blower motors are operating under
their full load AMP rating (FLA). The FLA can be
found on each motor and the unit nameplate.
A. Return Damper Settings
Manually adjust position of
fi
eld installed dampers to
balance air
fl
ow.
B. Air Flow / Blower Speed Adjustment
Blower speed selection is accomplished by changing
the sheave setting on both fresh air and exhaust air
blowers. To set ERV for the required air
fl
ow (CFM),
the external static pressure applied to the ERV (duct
static) must be known. See the CFM vs External
Static Pressure chart for the appropriate unit to
determine the correct blower RPM for the speci
fi
ed
CFM and External Static Pressure.
After blower speed adjustments have been made. Ensure
that when the belt is replaced it is tensioned correctly.
The motor mounting plate can be adjusted to tension the
belt. If using a belt tension checker, adjust the span to the
appropriate setting and check the belt defection force.
The belt de
fl
ection force should be between 5-8 lbs or the
lowest tension at which the belt will not slip under peak
