Some of us may have customers who have encountered the pesky old Trane VariCone or air valve style VAV boxes. This outdated technology often consists of worn or broken end switches and/or burnt out damper motors. Due to an overpriced retrofit solution from Trane, end users generally learn to deal with some of these boxes in their building just not working. Here at Stromquist we can provide our customers with a relatively painless and low cost retrofit solution using Honeywell D690 dampers and Honeywell ML6161 floating actuators or the MARD zone control damper assembly.
These 9 easy steps will get the box up and running. The first install should take about 4 hours, and once your customers are familiar with the process they will be able to cut the retrofit time down considerably.
Step 1. Determine the diameter of the box being retrofitted.
Step 2. Provide the customer with the proper size Honeywell D690 and Honeywell ML6161 actuator or MARD damper assembly.
Step 3. Power down the VAV box, open the access panel at the bottom of the box, and disconnect the wires going to the floating damper motor.
Step 4. Remove the duct from the inlet side of the VAV box, revealing the attachment hardware for the air valve assembly. Unbolt and remove the cone.
Step 4. After the air valve has been removed carefully, detach the air flow ring from the assembly. If the air flow ring has been damaged or is badly clogged you can provide a KMC SSS-series differential pressure air flow sensor as a replacement.
Step 5. At this point there are two directions the installer can go to attach the Honeywell damper to the box:
a) Option one is to attach a piece of sheet metal to the inlet side of the box with a hole cut in it to match the outside diameter of the round damper. Then insert the damper and attach it to the back of the box with angle brackets and use duct mastic to seal the edge.
b) Option two is to have the installer fabricate a flanged ring with an inside diameter matching the outside diameter of the new damper assembly and a flange that is wide enough to cover the excess in the opening left by the air valve. Use sheet metal screws to attach and duct mastic to seal.
Step 6. Notch the inlet side of the Honeywell damper and install the air flow ring or cut a 1″ hole in the inlet side of the damper and install the KMC SSS-series differential pressure air flow sensor. Then hook up the air flow pick up tubes.
Step 7. Install and/or wire the Honeywell ML6161 floating actuator on the newly installed round damper.
Step 8. Reconnect the duct to the inlet side of the damper and re-seal.
Step 9. Change the run time in the VAV controller from 360 seconds to 90 seconds to match the run time of the Honeywell ML6161, and reconfigure for new air flow sensor if needed.
That’s it! Less than 10 easy steps to retrofit the antiquated Trane air valve without replacing the VAV box!