We have approx. 55 Trane packaged rooftop HVAC units that need replacing these are all from 1991, i have been looking at options for replacing these units with something more reliable and energy efficient.
Started looking at the Airedale co. they have many options available. We have a new Middle School attached to the High School that is 5 yrs old, this school is equipped with a Trane chiller and two hot water boilers, this mechanical room is within working distance to the classrooms & rooftop units i would like to replace.
My idea was to check with the engineers for the needed capacity of the classrooms and estimate what if any would be available from the new chiller and the two boilers, if we still have some capacity available
We could then look at what it would take to install a 4 pipe system and a fresh air system to hook to the existing duct work in the classrooms, & new ceiling mounted cassettes .
Replacing the RTU'S with similar unit's may be the least expensive way to go, but with so many other options like Variable Refrigerant Flow, and Ground Source Heat Pumps, or hot and cold water systems i want approach the proposed replacement with an open mind and start here doing some research.
Many of you reading this may have already completed similar conversions, and if you can help i would like to read about your conversion's and configurations.
We live in Kansas so the temperature extremes are off the scale at both ends of the spectrum some times.
Thank You,
Brian Meyer
USD 465
Here is a link to Airedale www.airedaleusa.com/.../airedale_naHome
I'd like to offer a few options you may want to consider. I recently replaced several similar vintage units on one of our county satellite offices. You can likely purchase direct replacement gas fired DX roof top equipment with a much higher EER that would operate at the same efficiency as your central chiller / boiler plant equipment. And be sure to ask for a price for the higher EER model (basically a bigger condenser coil) I could get this for about $1000 a unit more, and the payback for the extra expense was 5 years or less. Make sure to get fresh air economisers, and have the entire air system balanced when complete. Make sure all your centralized digital controls are commissioned and interfacing with the Trane equipment. If you don't have a DDC system, invest in that instead of the piping to the new Airdale equipment.
You have a lot of units and because of their age they likely take a lot of maintenance. The newer equipment is better. And you don't have the whole school down if you chiller plant is off line (your added equipment just used up all your redundancy), and you can work on the equipment on the roof instead of in the class room (no overtime).
Look for rebates for new, energy efficient equipment from your utility companies.
Thank You for responding, this sounds like good advice to replace with similar equipment ,we do have Automated Logic DDC controls installed on the majority of our equipment.
The fresh air balancing , controls commissioning, and asking for a rebate from our utility co. are all great ideas.