Door (front door)
Anyplace but above the tub/shower. The best places would be about the commode or vanity. Center of the bathroom is another good location. In the place of the existing fan is the easiest. Use a combination fan heat lamp.
I installed mine just out the shower... where I dry off... its warm
Above where you stand or sit when you are wet and cold in the bathroom after bathing or showering. Not in the shower area itself.
Heat lamps are often installed in bathroom ceilings. You can find a variety of fixtures from a single bulb heat lamp fixture to a combo heat lamp vent fan and ceiling light. Heat lamps require a timer on the switch so they will automatically turn off if left unattended.
The heat lamp would be installed where it is needed. The only place the lamp is not permitted to be placed is over a doors swing radius. This is in the electrical code to prevent a door that is left opened and in a position directly under the lamp. The heat from the lamp has the ability to raise the temperature of the door to its combustion point and set it alight.
over the toilet
A ceiling heat lamp should be placed over an empty space so that it doesn't overheat anything in the room. Putting the heat lamp over the shower rod could start a fire and over a toilet seat could make the seat too warm and burn someone.
No problem. But watch the wattage on the bulbs. The heat is going to go the opposite direction. And the lamp is ment to be in the opposite stress position so that it could be much less stable than when sitting. But wiring wise it is the same, just wire the two wires in the ceiling to the two on the lamp. And there may be issues with code requirements. Overall it is better to be safe than sorry and use a lamp designed for the ceiling.
This is old school technology and hasn't been done for years in construction. What used to happen, the bathroom being a small room didn't have much ceiling area. Centrally locating the heat lamp fixture to a good position sometimes positioned the fixture in the radius of the in-swinging bathroom door. On many occasions the door was left under the heat lamp with the lamp on and the door caught fire from the build up of heat from the lamp. The electrical code made a revision to keep the fixture out of the arc radius of the door and this made for some strange locations of the fixture. The installing of heat lamp fixtures has just gone out of favour. It has been replaced with in floor heating in bathrooms.
what the function of lamp holder
To securely attach a lamp to a ceiling using a threaded rod, first, drill a hole in the ceiling that is the same diameter as the threaded rod. Insert the threaded rod through the hole in the ceiling and secure it with a nut and washer on both sides of the ceiling. Then, attach the lamp to the threaded rod using appropriate hardware. Make sure the lamp is securely fastened to the threaded rod to prevent it from falling.
The force responsible for holding up a lamp hanging from the ceiling is called tension force.