well its a concrete room with a layer of plastic sealing the room. and its in the basement.... meaning its the only room down there, its basically like a room concrete block under the house.... so its kinda col. but i live in wa state. so right now its still a bit chilly. but when summer rolls around it will be good. I have 2 40 watt flourescent tubes right now. when the plants get bigger it will become 4 tubes. im guessing around the cups its good temp around 70 ? (dont have a thermometer yet) but in the room in general, feels like 55.