10x10 grow tent

I have a big storage building that I was thinking of putting a 10x10 grow tent in. There is no heat in the building. The ambient temp in the building is going to be cold this winter.. it regularly drops to 20 degrees f or lower. I have 3 1k lights in the tent. Will the lights be enough to keep the tent warm during lights on? I also have a 12000 btu heater for lights out. I'm leaning tow ards no but I would like to get some other opinions..

3 x 1k lights is more than enough to keep it warm with the lights on, infact you will need to cool it down!

That's good to hear Rob... I have a 12,000 btu portable ac/ heating unit I was thinking could fit the bill for lights off heating and lights on cooling.. it has an internal thermostat that will use both heater and ac to maintain a set temp...