Chiller vs Direct Expansion system question
Chiller vs Direct Expansion system question
(OP)
Dear fellows:
I´m facing my very first design job of a large A/C system. Most of my previous designs involved residential and light commercial DX systems, but this one is of industrial size. I remember from a seminar that there´s a particular system size range where the benefits coming from potential short-term energy savings begin to offset the increased inital costs of chilled water systems compared to DX systems. I cannot recall what system size range was it. Could someone help me out with this? Thank you.
I´m facing my very first design job of a large A/C system. Most of my previous designs involved residential and light commercial DX systems, but this one is of industrial size. I remember from a seminar that there´s a particular system size range where the benefits coming from potential short-term energy savings begin to offset the increased inital costs of chilled water systems compared to DX systems. I cannot recall what system size range was it. Could someone help me out with this? Thank you.





RE: Chiller vs Direct Expansion system question
There is no one number for everyone. Operating costs, equipment costs, hours of operation all vary.
BUT! you are in luck. There is a simple little calculation where you spend an hour or two figuring out the ballpark costs of the equipment in each option and estimate the energy costs. From this you get a rough payback. Then you go to your client and say, here are your options and here are the costs associated with each, and here is the payback for the more expensive option, and here are the maintenance requirements. Which one do you want to pay us to design?
RE: Chiller vs Direct Expansion system question
Ken
KE5DFR
RE: Chiller vs Direct Expansion system question
RE: Chiller vs Direct Expansion system question
The guts of it was an energy comparison with different types of experimental systems some DX and some water based etc and the results did not appear overtly conclusive. Now admittedly this did not include maintenance, which is a big aspect of the decision, but is clearly relevant to what you are trying to determine.
The average supercenter is about 200,000ft2, which by anyones rule of thumb (irony?) exceeds the numbers you suggested.
This american love of packaged DX systems at all costs is a tad mysterious, but low cost installation, low repair cost and redundancy must count for something.
RE: Chiller vs Direct Expansion system question
Good luck.
HVAC68