Need Temperature Control Help

Im getting ready to build a grow cab thats 39" tall 28"wide 16" depth. I have 4 85 watt dual spectrum lights that create practically no heat. but the problem is that the weather temp is going to kill anything with in that space within days. no on hot days it reaches a good 95 degrees here. I was wondering what do you recommend fan wise that i use to keep the space between 70-80 degrees? (be a little easier if the was winter )

Where are you putting your cab? It may get 95 outside but thats no big deal if your cab is in a room with a/c. Plan for a max of 10 degrees above outside in a well sealed WELL ventilated grow room with air HID's. But with your lights heat should not be much of a problem pull air from low through passive vents and exhaust high in your cab with a good fan. You don't have much room there what are you growing how many? Remember to consider the height of pots or hydro units, on top of the height of your plants. Also plants double in height during flowering. Temps above 90 can be tolerated for short periods from my experience but I would not leave em in that heat for long! Good luck!

What about heating? My little setup is in a crawl space and its winter where I am now, So plants get cold and its been a month since I planted a baby and it only has 2 leaves about as long as your thumb.

You need some climate control for that space they sell controllers online that you plug fans and electric heaters into (or if you are going cheap buy a small electric heater at wal-mart with an adjustable thermostat. Just make sure your heater is not blowing right on the plants. For cooling you might be SOL but I would think that a crawl space would be cooler than outside. You can build an evaporative cooler with a box fan 5gal bucket a pump,and moss wick mat(they sell them for replacement swamp coolers) and a five gallon bucket but the best a cooler will drop temps 20 degrees below outside and only if the outside humidity is very low.