Rooftop units vs. Chiller

[dburgie]

I am an intern in Davenport, IA trying to reduce my company's energy consumtion.

We currently have 70+ rooftop A/C units that provide 725 tons of air conditioning to the building. The building is a single story manufacturing plant, with offices. The building is around 200,000 sq. ft. and 90% of the building is air conditioned.

I was wondering if it would be economical to install chillers and new AHUs to save money on electrical bills. Or is it possible to use the existing rooftop units as AHUs for the chiller?

If anyone has some advice for prices, economics, energy saving possibilities, or just general ideas, I would appreciate your help.

[masterelec-chaz]

ground system in you would save. It uses the ground core for cooling. you would need heat pump that cool and heat. You can run gleco through the system the core would probably increase. You would need to install evaporation tower to assist. The core temp. The overall cost of in stall would be high but I think if you ran the number on a spread sheet the pay off would be in about 10- 12 years not to bad.

[outside rep]

well hay lets open a can of worms :D



Central Plant will be cheaper to run , especially at that tonnage range compared to a RTU system also maintence will be less

Yes/no you can reuse your RTU for chilled water
Yes if its a custom unit or a large enought RTU
No if its a small RTU that cant take the extra coil face that is need to go from Refrigernt to Chilld water

regardless you will still need RTU units to do fresh air exchange





BUT since this building is alread designed this way the only real world idea is , new RTU with Chilled water and hot water coils. with a central Chiller/ boiler plant


http://www.epsilonfab.com for you central plant
http://www.mcquay.com for your airhandlers/ chillers
and for chillers check out the McQuay WMC chiller payback on those is with in three years :D