Here at the Tucson Branch, we just finished a project for one of our clients.
The work included removing and replacing eight chilled water air handlers, including improvements to the chilled water piping and high voltage electrical service for the Spa Building.
The project was unique in that, due to the access roads and surrounding landscape layout, we had to bring in a 165-ton crane to get to most of the rooftop air handlers. The roads and parking lots at this location are very narrow, so we had to bring the crane in through a little used access road in the back of the area. Two air handler units were even out of reach of this large crane, which was the largest we could fit into the area. We removed those two units by hand and rolled them to a spot where the crane could reach them.
The existing air handler piping was cobbled together with a mish-mash of two and three-way control valves, and the existing strainers had no access for flushing. We replaced all the valves with 3-way type 24V Belimo type valves and put in easy-to-reach strainers with ball valve shut-offs. The electrical service was upgraded with all new wiring and service disconnects. New control relays for the blowers were added in weatherproof enclosures inside each unit.
As with many projects of this kind, when the existing units were removed, some of the ductwork was found to be less than professional quality, so we revised the connections with proper sheet metal adapters.
We worked closely with our client facility personnel to shut down the Trane chiller serving the building, help drain the chilled water piping and repair some leaking fittings below the roofline that were exposed during the replacements.
After all was complete, the new air handlers were checked out for proper voltage and rotation, and the control valves were exercised for appropriate operation. The piping was refilled, air bled, and there were no leaks.
Our Client is pleased with their new and upgraded air handlers, and we will be sure to continue with our working relationship for years to come. Our next project at this location may be replacing several casita rooftop gas/electric units by helicopter, as the access roads to these were removed after the initial construction and landscaping added for an effect of seclusion.