9VAV-SLM005-EN
Parallel
Fan-Powered
Feature
Evaluation
Suggested Spec
Multi-point, multi-axis flow ring or cross sensor to be furnished and installed by
terminal unit manufacturer. Single-point or flow bar sensors are not acceptable. Flow
sensing device shall be capable of maintaining airflow to within +/- 5 percent of rated
unit airflow setpoint when installed with 1.5 duct diameters straight duct, of the same
size as the primary airflow inlet, upstream from the unit.
Water Coil MBH Performance
Overall we have the highest MBH performance out of our competition. This high
performance is the result of our higher water pressure drop on the coils. Don’t let the
competition force you into a 2-row coil if our 1-row coil will satisfy the MBH
performance requirement.
Suggested Spec
HOT WATER HEATING COILS—Coils shall be factory-installed and shall consist of
aluminum-plated fins and seamless copper tubes. Fins shall have full fin collars to
provide accurate fin spacing and maximum fin-to-tube contact. Tubes shall be me-
chanically expanded into the fin collars. Coils shall be leak tested under water to 450
psig pressure. Supply and return water connections shall be on the same side of the
coil.
Water Coil Pressure Drop
At first glance, you will notice that the Trane VAV water coils have a higher water
pressure drop then the competition. Typically, water pressure drop of VAV terminal
units is not a concern of engineers since the units are piped in a two-pipe
configuration and the air-handler coil is in the same line. The air-handler water coil
pressure drop is what the pump(s) will be sized for.
Manual Secondary Cutout
“Electric heater shall be complete with automatic reset cutout and manual reset
cutout. The Manual reset cutout shall be capable of being reset by a switch, or push
button. Fusible links are not acceptable.”
Why is this important?
A fusible link is a small wire sized to melt when it receives more amperage than it was
designed to handle. Once melted, it can cool and complete the circuit again. This
safety issue is why Trane no longer uses fusible links.
Additionally, finding of a replacement part for a fusible link may be difficult. Therefore,
the unit would be down for an extended period.
Control Boxes as Standard for Units with NO Controls
What we do:
Field-Installed Controls:
Approximately 50% of VAV controllers in the industry are “plenum rated”. This means
they DO NOT NEED A CONTROL ENCLOSURE. If a control enclosure is required, the
controls supplier should provide it. After all, they know the size, shape, etc. of their
controller.
If transformers, disconnects, and/or fuses are factory-installed, then a control
enclosure will be provided to house these. (A control box is available as a
design special.)
Factory-Installed Competitive Controls:
When competitive controls are installed in the factory and the controller to be
installed is a plenum-rated controller, then no control box will be provided. If the
controller is not plenum rated then a control box will be provided. (A control box is
available as a design special.)
