Do I need a space heater?

I have 2 questions:

Background: In my basement there is a creepy crawlspace that expands far underneath the main floor. It's a perfect hideout for growing. I rigged up a box and put a tarp over it, upon which the plants sit. I covered the ceiling with sheets so dust doesn't fall and I installed 4 hanging CFL lights above my plants. The lights hang about 2 feet above the plants and I can raise up a foot or more if I need too. I then surrounded the area completely with a black sheet and then lined the inside with tin foil to ensure that light reflects from all angles.

Question 1: My crawlspace is a smooth gray concrete. I have 4 plants and 4 bulbs, but I'm afraid that with it being January it might get too cold. I have a fan blowing too, so I'm wondering if I should invest in a space heater. Would the lights be giving off enough heat that I don't need a heater? I don't have a thermometer either. Maybe I should get one.

Question 2: Ventilation. There is a small peephole window in my crawlspace. There is currently a board in front of it. I could pop it open but that presents two problems. Cold getting in, and possible peeping toms getting up in my shiz. Is there a way I can rig a fan to a duct that could create for ventilation and no peeping? I'm also concerned about electricity usage. This is my first grow, so I want to be sure to take all the precautions. Thanks kids. Everything I've learned, I've learned from rollitup, so keep it up.

~Big T

well, i would take down the foil, it causes hot spots on the plants and fries them. Paint the area flat white instead, it has a 85% reflection rate, better than foil anyway. Also doesn't burn leaves. The heater will be needed:
Plants like a temp of 70-80 degrees farenheight in daytime, and no more than a ten to fifteen degree change at night time. NOT TOO COLD......check out my journal a few pages back to see what happens to cold plants. They DIE!!!!

Those flouro's won't produce any heat at all down there. Get a heater and hook it up to a thermostat. Buyt you'll need to make sure your fans kick off or down to low at night, to stop any more cold air from occuring. I leave mine on med all the time, and it works fine.
For the ventilation, don't go cheap!!!!
You don't want johnny neighbor smelling the bud from his house, and he shouldn't be able to see it either, or any light from it.
I would spend the money you saved on lights on ventilation(inline fan, scrubber, and all)!!!

Your florescents are two feet away? They should be only a few inches away from the tops what is their wattage

Hi,

First things first, get a thermometer preferbly one that records the min and max temps, they rearlly are not expencive. You need to know how hot or cold that space is getting. Too hot you will kill you plants. Too cold and they wont grow. You would want them to be keept at around 70f, some may say hotter or colder but you will learn what your plant likes by how it reacts to different temps. Its better to be a little colder than to hot.

As your using CFL lights they will produce very little heat so you will want them to be practically ontop of your plants the get the most from the lights.

I would advise you to replace the silver foil with a myler sheeting, if you can afford as myler can be expencive, silver foil can create problems with hot spots and are not as reflective as they seem as they dont reflect the correct light waves properly.

Ventilation is always good for replenishing the air with fresh and removing excess heat, but any venting must not let any light into the grow room, light pollution form outside will mess with your plants. So maybe some black messhining to cover duct holes, also a bend in a duct run will stop people seeing and help stop light polution.