I have a question about the return air on this unit or any other unit for that matter and its this, as in the pictures show, which is better & more efficient to run this unit? With the door leading into the room open or closed? There is a vent on the door too. I say close the door but the wife insist that it stays open. By the way, with it open it covers the vent, and when closed it does not.Could someone help me with making the wife understand this and the reasons why? Any thing is helpful. Thanks

IFthe vent in the door is large enough (at least as many square inches) as the furnace door, closing the wooden door will not make any difference. Otherwise, leave the wooden door open or remove it. You can get grills at most home centers if you wanted to add to the one in the wooden door.

I also agree with the point that one can go for the AC. An air conditioning system provides a lower temperature in homes, offices, building, etc. An AC is the much better air cooling option as compared to the other cooling system. I also have an HVAC system in my home which I generally used for the heating, ventilation and air conditioning purpose. You can check this site to know more about the HVAC system if you are looking to install a new AC or heater in your premises.