Keeping a tent cool in summer, warm in winter, and what to do in a power outage

Run the light at night in summer and in the cool part of the day in winter, keep the room around the tent comfortable, and keep pots off cold floors. In an…

Most grow problems in a tent are really room problems. The tent copies the air around it.

Summer

Run lights during the cooler hours, for example overnight.
Only move a detachable light power supply if the manufacturer explicitly permits remote mounting. Keep the clearances and don’t modify wiring.
Vent hot exhaust air out of the room, not back into it.
Cool or dehumidify the room, not just the tent.

Winter

Keep pots off cold concrete with foam board or risers. Cold roots slow the plant even if the air seems fine.
Run lights during the colder part of the day so their heat helps.
Only cut back exhaust if humidity and air quality stay under control. Humidity often rises at lights-off, so don’t give up moisture removal just to hold on to warmth.
A properly installed room-heating setup is the better choice. An oil-filled or radiator-style portable heater isn’t automatically safe. Keep it at least 3 feet from anything combustible and away from water, and plug it directly into a wall outlet, never a power strip or extension cord. Don’t leave a portable heater running unattended or while you sleep.

Power outages

If humidity builds up with the fans off, open the tent door a little.
When power returns, restore the normal light schedule and check the timer. The effect of an interruption depends on its length, the cultivar and other conditions; do not assume the crop is unaffected.
Old plug-in dial timers stop during an outage, so reset them to the correct time.
Hydroponic roots in still water can suffer within hours. A battery air pump is cheap insurance.

Keep working smoke and carbon-monoxide alarms as appropriate for your home. Never use fuel-burning heaters or generators inside a tent or living space. If you use a portable generator during an outage, CPSC says to run it outside, at least 20 feet from the home, with the exhaust pointed away from buildings. Follow the electrical connection instructions, and don’t backfeed house wiring.