I keep my aroids and other humid loving plants in my washroom and also have the dryer unvented. They love it.
Sounds like you've got some work to do but also have a good idea as far as the extra heat usage. My grow room stays around 65-70F from the lights in the winter without another direct heat source. With the door open to the rest of the house it stays 75-80F while the lights are on. I have to run a small space heater when the lights are off. My aroids would go dormant if I didn't and the other tropicals wouldn't be too happy.
I'm not sure I'd bother with the plastic because the plants will need that heat as well. Maybe line the complete growing area with plastic? You'll need a heat source down there when the lights are off, maybe even when they're on in your zone.

Sure you wouldn't rather have the heat leak and sift thru the basement ceiling instead of trying to channel it with plastic? It ought to sift more strongly in the area directly above the lights, which is hopefully the cooler rooms you were referring to.

Not to mention that some would naturally channel itself towards that doorway anyway.

I guess you can also rig something that would better accommodate both methods.

Darn! I did it again. I knew what I was trying to say but didn't type it in a way that others would!

During late fall, all winter, and early spring, when the temps are cooler, I would let it rise unabated. Only when it gets warm enough to need AC or at least not need any additional heat, would I put plastic or something similar on the top of it.

It doesn't get cold down there, not with the furnace, water heater and dryer all in the room but it doesn't get hot either. I figure I can keep the temps between 60-82, which would be ideal for tomatoes.

Mike

Mike I think the added heat would be welcome in the winter but a pita in summer. Summer rates are high and for all the extra heat you have to pay for the air conditioner power too. Double Whammy! I grew lettuce all summer and had to drop down to 1 twin 32 watt t-8 fixture during the hot times. Now You know my garden is in the kitchen and that could be a lot different than the basement. Btw I have fired up the lights and started the winter greens. I had indoor pock choi last week. How nice to have greens with no bug holes in them, I think it makes them taste better,don't you? 1800 watts = 6138 btu per hour. 1 watt = 3.41 btu.

Curt

Curt,

I doubt I will worry about summer growing - I have a 900 sq. ft. garden plus am probably going to be leasing about 1/2 acre of other ground. If I find an early variety I like, I could have enough toms so I could shut the grow down in mid-July.

Mike

MIke I wrote that response to your first post and forgot to send it. Company stopped by. It was for your first post only, not the second one, so our post were in the mail so to speak. Clear as mud right? lol

Curt

Curt,

I see, said the blind man to the deaf guy!

Mike