Energy Recovery Run Around Loop Sizing

[belz]

I need to size a run around coil energy recovery loop to recover heat from a group of fume hoods exhaust ducts and use the energy to preheat my make up air. Does anyone know of a good design guide or program for sizing the coils and flow rates? What is the limiting factor on how much energy can be recovered from the exhaust air stream? Would it be the exhaust air stream dewpoint to prevent coil frost? What is the recommended delta t across the glycol side?

 

[steam4]

Some good coil design software can be found at:

http://www.marlocoil.com

 

[ChrisConley]

I think Heatcraft also has run-around coil sizing software

http://www.heatcraft.com

 

[lilliput1]

If you factor in maintenance & health hazard potential, heat recovery of fume hood exhaust will not be attractive. About 45% to 50% efficiency is what you can get. Then you have to add heat to prevent frosting at low ambient. Include fan & pump power penalty. Make sure you have space for coils & filters. Provide bag in/bag out filters to protect coils.