Humidity---physics question?

Question

A cold room with high humidity feels less chilly than a dry room with the same temperature. Why is that?

Answer 1

I disagree with your observation

Answer 2

I disagree as well :)

Answer 3

Your skin is continually sweating and evaporating that sweat to cool you off. If the humidity is high, the rate of evaporation is low, the cooling effect is low. If the humidity is low, the evaporation rate is higher, the cooling effect is higher. So, for a given temperature, higher humidity will make it feel warmer.

Answer 4

You are correct in your observation.  

The HVAC industry use psychrometric charts which are graphs that can be used to determine the relative humidity by plotting the wet buld vs dry bulb temperature.  

On the psychrometric there is somtimes shown an area that is called the "Comfort Zone" . This is an area where 90% of the population will find the conditions (humidity and temp) comfortable.

In winter the heated air can be very dry, a person can feel coo in a 68F room if the air is too dry as their sweat is evaporating to quickly which cools their skin. A person in such an environment would want to raise the room temp and might find that comfort is achieved at 71to72 degrees.

However if the humidity in the room is increased by the use of a humidifier, the increase in humidity reduces the sweat evaporation rate. The person isn't cooled as much and would therefore find comfort in the 68 to 69 degree range without haviing the desire to raise the thermostat.

Having proper humidity can save energy, as in the winter time example above a lower energy means of adding humidity eliminats the desire to raise the thermostat and burn more fuel.