Whatever it is set to on your heater's control keypad.
Ultimately, it should be whatever temperature makes you comfortable, but I'd say a normal temperature would be around 65 degrees or so.
55 degrees above zero Fahrenheit
Depending on the year, make, model along with if it has single or dual a/c systems and what the outside temperature is, it can be between 36 to 48 degrees...... Simply, the A/C vents temperature should be whatever you set the thermostat as.
in the floor.
Heating vents should be placed near or on the floor in a room because heat travels up not down.
Heating vents should be located near the floor since hot air rises. If the heating vents are located near the ceiling the heat would stay there and not warm the room.
on the floor on the floor
Heating vents should be placed on or near the floor because heat rises. In rising, it will warm the air of the room. If the heating vent were near the ceiling, the room would stay chilly, even though heat was being poured into it.
There is probably a fuel leak somewhere. You should have a professional check it out ASAP. There is a possibility of a fire if left alone.
A thermostat for heating or a thermometer for air temperature is typically placed on an inside wall (not outside wall), and away from heating vents or direct sunlight.
replace? why not fix it?
So it has something to heat and blow back out, thus, heating your home. The stuff coming out of your vents has to come from somewhere..