Always try to seal the room(s) from escaping heat. Especially HVAC vents, lights, bathroom exhaust fans, bottoms of doors, wall air-conditioners, etc… Cover windows pane with blankets or equivalent to minimize loss of energy from cold windows.
Remove items that you would not leave in your car on a hot sunny summer day. Candles, lighters, many foods, candies, etc…
Unplug all electrical items and do not place electrical items directly in front of the heater. Electrical items are rated for higher temperatures than you are heating, just avoid the direct heat coming out of the heater.
It is best to bag clothes, sheets, etc… and run in the clothes dryer for 20 minutes on high. Never leave clothes laying on the floor or other surfaces or they will act as an insulator and it will be difficult to heat under them sufficiently.
Open all drawers and separate all items so hot air can get everywhere easily.
Stand or block box spring and mattresses so hot air can contact all sides.
Place all fans blowing in the same direction along the walls in the area you are heating to circulate the hot air into every nook and cranny. If possible place at least one fan per wall. Turn on fans to ensure air movement is sufficient. Add more fans if it does not feel like a whirl wind (tornado type effect).
Place heater(s) so that the air is being immediately swept up by the fans and the hot air coming directly out of the heater is not directly hitting any furniture or building materials before being blown about by the fans.
Use no less than 1 heater for every 150sf in a normal room of ceiling height of 9’ or less for maximum performance. You can never have too much equipment, only not enough.
Turn on heaters and make sure all heater light switches that have power are on. Heater switches will not turn on if you do not have power connected to the respective heater switch. This is ok if you are doing this on purpose because you don’t have or don’t need the full power of the heater.
Always check for fire sprinkler’s installed in a building. Keep heat level at fire sprinkler head a minimum of 30F below the trigger temperature of the fire sprinkler.
Walls and ceilings made of block or concrete require more heat because they are more conductive of energy than drywall. This means 1 heater will heat less space when you have walls and/or ceilings with block or concrete. 50% more power is a general rule for these rooms. All buildings are not created equal and more conductive materials take more energy to heat.