Passive Hot Gas Reheat system
Passive Hot Gas Reheat system
(OP)
We are installing additional cleanrooms in our aseptic pharmaceutical filling operation. The AHU that the engineering firm specified has what they are recommending a "passive hot gas reheat" system that utilizes a closed refrigerant loop with flow control to cool/dehumidify the mixed air and then reheat the supply air. It will provide tight humidity control with improved energy efficiency. I am not familliar with this type of system.
This "Thermosyphon" system pretty much shows the general arrangement...
http://www.carolinaheatpipe.com/products.html
Does anyone have experience/opinions with this they would like to share?
Thanks
Ben
This "Thermosyphon" system pretty much shows the general arrangement...
http://www.carolinaheatpipe.com/products.html
Does anyone have experience/opinions with this they would like to share?
Thanks
Ben





RE: Passive Hot Gas Reheat system
Explanation looks logical, they likely tested it before releasing to market, and now it is only real operating data that can confirm the concept over time.
Cost-benefits analysis makes sense during specifying stage of project, I don't know what would you need to do now. Do you have any specific question?
RE: Passive Hot Gas Reheat system
I was hoping for some operators to weigh in and have opinions (i.e. headache/great/doesn't do much).
RE: Passive Hot Gas Reheat system
Looks like your actual cooling coils are chilled water. There are DX units that use the actual hot gas from the compressor to reheat the air, but that does not appear to be the case here.
RE: Passive Hot Gas Reheat system
As for our units, yes, they are chilled water cooled.
Since we require tight humidity control (application is a pharmaceutical cleanroom) there is a lot of extra energy expended to cool/dehumidify and then re-humidify the air. I can't imagine that adding a system like this to an air handler wouldn't provide a relatively quick ROI. Once we get the detailed designs complete, there should be performance data from the manufacturer that can be used to estimate the energy savings.
Thanks for the help!