HELP! Kitchen is cold in winter time with Hoods running

My bar and grill is in NW Iowa and with the winter months hitting now we are noticing that the kitchen is getting colder and colder.  At night when the Hoods are not running it is fine but when they are on during the day it drops like 20 degrees.  Has anyone else experienced this?  What do I need to do to keep warm in the winter.

the fans are sucking your heat out. just as in the summer when you run the AC and turn the fans on, it gets hot in there.   Keep running the fans at a minimum.

your hood does not have return air on it.  I had the same problem.  My hoods pretty much sucked the floor out of the place though hahahahha

good point, Forgot about the make up air returns. LOL

Dog,
  Did you build your hood system?  Tell me about your makeup air, where are the vents located (in the hood itself?)?  How far is the topside intake air unit from the exhaust fan?  Does the makeup air unit have it's own fan or does it depend on "draw" from the exhaust fans?  Is the makeup air filtered?

You don't need the hoods running all the time, turn them off every other hour, if your not cooking something, keep them off.