Does putting a wet paper napkin on the thermometer really make it warmer?

Question

I have seen a lot of my teachers at school put a wet paper napkin on their thermometer whenever the class gets cold & it works! But I am curious to know, how? (what is it with the wet napkin & thermometer that makes it warmer?)

Thank you so much for answering. I would choose you both as best answer, but I chose the one that had more detail in understanding. Thank you for answering!

Well, actually I thought I choose now, but I have to wait for 4 more hrs. lol!!

Answer 1

I think you mean a wet paper napkin on the thermostat. Evaporation is a reaction that removes heat from it's surroundings. So the water on the paper towel will be evoporating and making the thermostat think it is colder then it really is in the room. Thermostats are designed to turn the heat on when the built in thermometer reads cooler then the temperature that the thermostat is set at. So basically they are tricking the thermostat into thinking that the room temperature is colder than it really is so the heat comes on.

Also they could just be using cold water which would have the same effect.

Answer 2

Wet paper will evaporate, and that uses up heat.

Putting a wet paper napkin on the thermostat makes the thermostat register a lower temperature than is really in the room. So the furnace would come on more often to warm up the room.

So the wet paper napkin makes the thermometer colder.

Answer 3

Putting the wet paper napkin on the thermometer lowers the temperature on the thremometer to the dew point temperature of the air........which is always lower than the dry bulb temp.....this tricks the thermostat into thinking it is colder in the room than it really is, so the heater comes on.

Answer 4

I leave the right open... If the tank is on a stand it really is closed in (has a door) open the door to that and characteristic a field fan blowing air out from below the tank ,have yet another fan blowing air in the course of the right of the tank this can cool it down 80 4 isn't too undesirable. My tank receives that warmth in the summer season.. the most excellent I actually have had it became 87 see you later because the temp does no longer swing to immediately then you rather might want to be ok