Trane VAV-UCM 4.2, Инструкция по установке и обслуживанию, Страница: 54 / 88

54 VAV-SVX01C-EN
Air and Water Balancing
Chapter Overview
This chapter contains information about the following:
• Air Balancing
• Water Balancing
Air Balancing
After the unit has been mounted and all electrical and duct connections have been made, the air
distribution system should be balanced. The proper variable air volume balancing procedures
depend on the type of VAV system used and the options specified on the VariTrane® unit. This
section will cover the basic balancing procedures and calibrations needed to balance an air
distribution system using VariTrane units. This section suggests only one balancing procedure.
Since there are many possible air balancing procedures, keep in mind that these procedures are
only suggestions.
Note: Before performing these balancing procedures, the calibration command should be
initiated at least 15 minutes prior to the balancing procedure.
System Checkout
• Check the VAV system installation for conformity to design.
• Walk the entire system from air handling equipment to the terminal unit to determine variations
of installation from the plans.
• Check for inadvertent obstructions in the ductwork (such as closed fire dampers).
• Insure that any turning vanes, filters, and dampers (both volume and fire) are installed in the
correct position.
• There should be a 1.5 duct diameter long run of straight ducting into the VAV units inlet.
System Setup
• Set the outside air dampers to their minimum position.
• Start the supply and return air fan(s).
• Before balancing the system, ensure that there is enough CFM for all zones.
1. Drive all VAV boxes MAX.
• Starting with each individual branch duct, open all the VAV units in that branch duct to the
maximum cooling position.
Note: This can be done using Rover or EveryWare by giving each UCM a "Drive Max " command
or by rotating the Zone sensor set point knob to the " * " position, and hold the TOV ON
button for two seconds. The damper will remain at its maximum set point until the zone
sensor knob is moved back into the normal operating range.
2. Read airflow at the most remote unit. In most systems, this will be the VAV unit located furthest
from the fan. This will be the unit in the system that will be critical from an air delivery set point.
If airflow is not adequate, increase the supply fan CFM to achieve adequate airflow.
• If the CFM is at or above design, the system can now be balanced. If the measured CFM is below
design, insure the VariTrane unit is in full cooling position.
• If the air delivery through this VariTrane unit is still below the design requirements, increase
the supply fan CFM to achieve adequate airflow.
Note: To increase supply fan CFM check to make sure VFD/IGV are giving max output. If not at max
output; adjust discharge static setpoint until at max output. If already at max output then