SCVH VAV COOLING/HEATING
SCVH Operational Air Flow
The Performance Aire SCVH provides VAV cooling and heating for the temperature requirements of the zone space it serves.

Entry ways, individual office spaces, and conference rooms are problem areas that need their own options for climate control.
Throughout the course of a day these spaces vary in temperature due to being influenced by changing factors.

The SCVH features separately adjustable set-points for cooling and heating, allowing precise comfort control. It is the solution that provides comfort for individuals in difficult spaces.

FEATURES

• Control functions that automatically adjust temperatures in individual workspaces.
• No control wiring, pneumatic piping, or added system pressure required.
• Existing systems are easily upgraded with the various diffusers available.
• Separate and adjustable set points for heating and cooling.
• Easy access set point adjustment.
• Diffuser constructed of 24 gauge sheet steel.
• Architecturally pleasing, blemish free hemmed face panel.
• Cone shaped diffusion damper.

HOW IT WORKS

The SCVH is a thermally powered VAV diffuser which is completely self-contained and self-powered. The mechanism is operated by four thermostatic actuators. The actuators provide VAV room temperature control in heating and cooling. The simple design is based on fewer moving parts to hinder the actuator’s response. A cone shaped diffusion damper creating less turbulence allows complete and even air distribution. 1/8" foam padding for quiet operation.

Change over between heating and cooling modes is determined by supply air temperature. When heating cycle is initiated, actuator #1 will react first, lowering damper to full open position (full heating).

Then the heating slave actuator, reacts at 78 degrees or greater, positioning the heating u-arm to engage the room thermostat heating control actuator.

As the room warms, the actuator begins to sense the room temperature to vary the heating supply volume which will achieve and sustain the desired room temperature. The factory set point of 74 degrees is adjustable between 72 - 78 degrees. For less heating, turn the actuator clockwise. For more heating turn the actuator counter-clockwise. Each full turn will equal plus or minus 2 degrees.

A drop in room temperature and unit will respond by opening to increase heating volume until the room temperature reaches the desired set point. VAV cooling control is initiated when supply air is below 68 degrees. In cooling mode the first two actuators do not react. This engages the cooling control actuator which will vary the supply air when cooling. A rise in room temperature and unit will respond by allowing cool air into the space until the room temperature reaches the desired set point.

 

MAKING ADJUSTMENTS

FACE PANEL REMOVAL FOR TEMPERATURE ADJUSTING

The solid face panel is held in place by four spring clips. To remove the face panel for room temperature adjustments, approach panel from the induction trough side (the rectangle opening) reach above the panel on both sides with your forefingers until you are able to place your forefingers behind the spring clips. Using your thumbs on the front edge of the panel push the panel back or away from you while pulling the spring clips forward or toward you with your forefingers. Lower the panel and pull forward to disconnect the panel from the rear spring clips. When reattaching face panel the induction trough must be positioned directly opposite of induction wing.

COOLING TEMPERATURE ADJUSTMENT

All “Smart“ diffusers feature an easy to read room temperature set-point scale. Room temperature adjustments are made by simply turning the VAV room temperature control thermostatic actuator #4 clockwise for a cooler room temperature and counter clockwise for a warmer room temperature. Determine room temperature set-point by aligning the end of the actuator with the indicators on the temperature scale. Each full rotation or each indicator on the temperature scale will equal plus or minus two degrees. For factory set-point of 74 degrees, turn actuator clockwise to stop, then turn counter clockwise three full turns.

HEATING TEMPERATURE ADJUSTMENT

The room temperature set point is controlled by the red actuator. For a cooler room temperature turn actuator clockwise. For a warmer room temperature turn actuator counter-clockwise. Each full turn equals plus or minus 2 degrees.

VAV thermal diffusers utilize significant spring pressure to accurately control the thermal actuators sensitivity to temperature change and reduce inherent hysteresis.

Note: When actuators are warm they may be slightly difficult to adjust.

VAV SQUARE PERFORMANCE / DIMENSIONAL DATA

Square Diffuser Performance Chart

MODELS AVAILABLE:

SC, SCW, SCAH, SCVH

DESCRIPTION:

SQUARE DIFFUSER PERFORMANCE CHART

• 6"/8"/10"/12" Inlet Duct Connections Available.
• SC provides VAV Cooling Control.
• SCW provides VAV Cooling Control/Full Open Morning Warm-Up.
• SCAH provides VAV Cooling Control with Adjustable Constant Volume Heating Control.
• SCVH provides VAV Cooling and Heating Control.
• Wax Type VAV Thermostatic Actuator.
• Throw values (ft) are based on following
terminal velocities:

Maximum 150 FPM
Typical 100 FPM
Minimum 50 FPM

Pt is total pressure (inch WG)

S - SOLID CENTER PANEL
C - VAV COOLING CONTROL
AH - ADJUSTABLE HEATING VOLUME
VH - VAV COOLING/HEATING CONTROL
W - FULL OPEN WARM-UP