Mammoth V-Cube - Manual (Page 16)

Airflow.Balancing
For proper performance the unit must operate at the spec-
ified supply and exhaust flow rates as shown in the me-
chanical drawings. Unit fan speed(s) and damper positions
are theoretically set at the factory based on the ductwork
static pressures and flow rates specified in the mechanical
drawings. If conditions change or verification is required,
airflow measurements should be taken using AMCA sug-
gested methods. This would normally be a velocity traverse
measurement or flow measuring station (FMS) installed in
the ducts. Where space is limited in the outdoor air and
exhaust air, pressure drop readings can be taken across
the energy recovery heat exchanger (with economizer heat
recovery bypass dampers closed, if equipped) and com-
pared to the submittal documents. Heat recovery perfor-
mance is tested in accordance to AHRI Standard 1060 and
is accurate to within +/− 5% if there is no dirt buildup in
the heat recovery heat exchanger. Should flow rates need
to be reset, adjust the outside air, exhaust air or mixed air
dampers, variable speed sheaves, VFD fan speed setpoint
positions or change the sheaves.
Flow measuring stations (FMS) and magnahelic gauges can
also be used to measure supply and exhaust flow. It is im-
portant to locate the FMS in the “warm side” ductwork to
minimize the effect of differences in air density, especially
when balancing during extremely cold outside conditions
or to take temperature readings and make the necessary
corrections if installed in the “cold side” ductwork. Air
density variations can affect the FMS by more than 15%.
The FMS should be located downstream in straight sec-
tions of duct and not immediately after fans or obstruc-
tions that will cause turbulent flow.
If the unit has been in operation before the air balancing,
ensure the unit filters are clean or include pressure drop
readings across the filter banks with the report.
Maintenance
Long-term.Storage.Maintenance.Procedures
Please refer to Appendix F : Extended Dormant Unit Main-
tenance Procedure and Checklist, for maintenance instruc-
tions to follow if the unit is to be stored for a period of
time exceeding one month. Following the instructions in
this appendix will assist in preventing potential unit dam-
age that may result from an extended storage period.
Maintenance.Summary.Chart
Please refer to Appendix G for a recommended list of
routine maintenance items and time intervals. A more de-
tailed description of maintenance items follows.
IMPORTANT
Before measuring supply and exhaust flows, the building
must be in its normal state:
• Hermetically close doors and windows.
• Shut down hot air generators and combustion
water heaters.
• Install all ventilation system components: filters,
grilles, diffusers, etc.
!
WARNING
Many of the following steps need to be performed with
the unit powered off and locked out. Disconnect the
main power switch to the unit before performing service
and maintenance procedures.
VCES-V-CUBE-IOM-1A 16