They're selling snake oil. There are so manys thing wrong with this proposal. First off, why do you feel you're not getting enough airflow? Is the room they used for their demo hard to heat or cool? If the existing 370 cfm is enough to keep that room comfortable, then there is no reason to pay money to increase the airflow. "More" is not always better. Your air handling system was designed to move air as an enclosed system. OF COURSE it's gonna move more air if you rig it to operate with the fan cover door opened. But again, more is not always better. I'll bet you could stand in that back room and *hear* the air rushing and whistling out of that vent after they took the blower door off. Your system should be set up to move the required amount of air as quietly as possible. You're also risking damage to the blower by making such a drastic change to the static pressure. The fan is designed to work against some amount of resistance. Lessen or remove that resistance and you could burn your fan motor out. A return in the basement is going to bring extra humidty and musty odors into your home. The air conditioning unit would have to work harder to remove the extra humidity. It could actually cost *more* money to operate. And if the unit was not capable of removing the extra humidity, you end up with damp air in your living quarters. This results in a cold, clammy feel that makes you feel uncomfortable. If you have some rooms that are hard to heat or cool, have a reputable HVAC company *calculate* how much air needs to go to each room. It's not a guessing game, and more is not always better. I noticed that you called the original installers and they blew you off. Forget them, they don't sound very professional. Try asking some of your neighbors for referrals, or check something like "craig's list". There has to be a reputable company in your area.

if the WH is putting off heat, then yes it is increasing the temps, but modern electric heaters have almost no standby loss. i would be more concerned with are your filters and both coils clean and not restricted, than with the minute heat your WH is producing. in my last post i said it should be sealed and ducted, but i meant to explain further. this way of doing it is not uncommon in my area in older homes. we do not have cold winters, so it really does not matter THAT much. but during winter you can feel the cold falling down from the attic and into the utility closets. the return itself should be sealed to the ceiling around it to prevent this, but it does not necessarily have to be ducted on down and a grill i8nstalled int eh wall. the only way to tell if it needs to be changed is to have a pro come look at it and see if there is a reason the unit is not operating to spec., be it the duct or another problem. as to the WH working harder, not really. IF it is fairly new then it is well insulated. put your hand ont eh WH and see if it is hot to the touch. the only place you should feel heat is the area around the outlet pipe and maybe the covers for the heater elements on teh side of the tank. if the tank is cool to the touch, then it is well insulated the air is not affecting it. you can have your apartment manager turn down the WH temp to less than 120 to save some electricity. WH waste more than you think. heck mine uses more than either of my HVAC systems!

I eventually had my HVAC guy come out and asked him. He said it was okay to partially block the heat vent, but if it had been the cold air return it would NOT have been okay. So I happily moved the frig to it's best place and moved the frig right up against it. So the heat vent is about halfway blocked and I just put one of those magnetic vent covers over the half behind the frig. I'm not an expert, but I think it helps to force more air out of the half that's not blocked. So, unlike most kitchen renovations, this cost me nothing. Yay!

It sounds to me like your duct system has leaks that cold air is getting into your system. Even if your ductwork is in concrete it should not drop your air temp that much unless cold air is getting in also. I would start with temperature readings of the return air temp at the return compared to the actual return air temp at the furnace. I would then check the supply temp at the furnace right after being heated and compare it to the supply temp. You might have to put some small holes in at the furnace so don't forget to seal them.