i have used cash crop.
it comes with 3 14w cfl bulbs. there is no way those bulbs will increase temp from 40 to 70+.
even with the benefit of being in an enclosed space. youd be lucky to get it up in the 50’s i think.
the box has a ventilation fan on backside,…that will exhaust the air from inside box. causing fresh air to be drawn in from the seams. if that fresh air is 40F…yeah, too cold.
if you changed the bulb, i stuck one of those UFO L.E.D lights in the CashCrop box after realizing the 3cfl bulbs were super-weak. but, that particular light didnt put off much heat either. to make up that much of a difference in temp, you would need an H.I.D type of bulb, in an enclosed area. and theyre typically too large to fit in CashCrop box.
there are alot of affordable tents available. like 3’x3’ x 6.5’ high. if you had an HID bulb in there, you might be able to get in the 70’s.
the tent i use is 10x10, and its about 40 degrees outside and maybe 55 in my garage, where tent is. with my 1000w HID bulb on, temp stays in high 70’s. for the hours when light is off. i have a small electric space heater on a timer, if i didnt, temp drops to low 50’s. which is pushing the limits of acceptable.