Heat Recovery Wheel in Lab??
Heat Recovery Wheel in Lab??
(OP)
Comrades,
I'm reviewing a design that incorporates a heat recovery wheel in a chemical lab school building (post-grad studies)...
I love the idea of heat recovery. I cringe at the thought of using a wheel that spins through a contaminated exhaust air stream into the make-up air stream. The exhaust stream includes hood exhaust.
My thought is that there's been a good salesman for this application and that the designer should re-think this.
I could be off-base and designs may exist that eliminate odor and contaminant reentrainment.
Your thoughts are welcomed and appreciated. -CB
I'm reviewing a design that incorporates a heat recovery wheel in a chemical lab school building (post-grad studies)...
I love the idea of heat recovery. I cringe at the thought of using a wheel that spins through a contaminated exhaust air stream into the make-up air stream. The exhaust stream includes hood exhaust.
My thought is that there's been a good salesman for this application and that the designer should re-think this.
I could be off-base and designs may exist that eliminate odor and contaminant reentrainment.
Your thoughts are welcomed and appreciated. -CB





RE: Heat Recovery Wheel in Lab??
You are right. Generally heat recovery wheels are not at all recommended for containment applications. It is a 'must not to do' rule as far as pharmaceutical companies are concerned. Even after using some filters (I doubt, what are they?) the entire system is to be validated for traces of active items which is very difficult as the concentration of containment may not be homogenous.(Even when HEPA filters are used)
Transfer efficiency of Heat recovery wheels is less when compared to other means. (High density may be the reason)
Moreover, If one AHU covers multiple areas, cross contamination is another problem.
Regards,
RE: Heat Recovery Wheel in Lab??
I was surprised by Quarks reference to lesser transfer efficiency with Heat Recovery Wheels. Not sure what they are being compared to... heat pipes, run around glycol recovery loop, air to air... Perhaps Quark will clarify for us.
Regards
RE: Heat Recovery Wheel in Lab??
We use flat plate HX for heat recovery in this application.
Venmar, Trane, Engineered Air, etc.. offer this so you can get an off the shelf size/item.
RE: Heat Recovery Wheel in Lab??
If by 'hood extract' you're referring to what I'd call a fume cupboard, then I wouldn't attempt to recover heat from these air streams, but just dump the air. They will contaminate the ducts, extract fans and heat exchanger, causing maintenance problems. They're probably only a small proportion of the total air extract.
RE: Heat Recovery Wheel in Lab??
RE: Heat Recovery Wheel in Lab??
Can you get the efficiencies you need from a heat loop?
RE: Heat Recovery Wheel in Lab??
RE: Heat Recovery Wheel in Lab??
I think that the present costs of such coils could make such a system uneconomic for a new installation. A cross-flow heat exchanger, if applicable, could achieve similar efficiencies with a much lower initial cost.
RE: Heat Recovery Wheel in Lab??