Temperature, Humidity and Ventilation Flashcards
Define Heat
Heat is a form of energy/the ability to do work. The random vibration of molecules of the body. Adding heat to a substance increases its molecular motion and potential energy and may cause it to undergo a change of state that is to melt or vaporize.
What effect does heat have on air volume?
Volume increases as air gets warmer
What effect does heat have on air density?
Density decreases as air gets warmer
Describe what happens to a substances molecular structure when heat is added
Adding heat to a substance increases its molecular motion and potential energy and may cause it to undergo a change of state that is to melt or vaporize.
Define conduction
Heat transfer through a substance from object to object (Warmer to colder) through physical touch.
Describe convection
Natural heat transfer through a fluid medium, liquid or gas (air). It is heated and then it expands, becoming less dense, giving it more volume.
Describe Radiation
Heat transfer through energy waves. Such as the sun heating the earth. (light waves, radio waves). Waves travel in straight lines and are able to pass through a vacuum; they require no medium on which to travel.
What is a BTU(in relationship to air and water)
The amount of heat required to raise the temperature of 55 cubic feet of air 1 degree F. Or, one pound of water 1 degree F.
Which direction does heat always travel
Heat always travels from a warmer object to a colder one.
What is the rate of heat transfer between a warmer object to a cooler one?
The rate is directly proportional to the difference in temperature between the two objects. The bigger the temperature difference the faster the heat transfer.
Define Sensible heat
The amount of heat required to change temperature in a substance without changing the state of the object.
Define Latent Heat
The amount of heat required to change the state of a substance without changing its temperature,
Define Specific heat
The number of BTUs required to raise the temperature of 1 pound of a substance by 1 degree F.
How is sensible heat measured?
By a thermometer or sense of touch
How is latent heat measured?
In BTUS
Define humidity
the quantity(amount) of water in a particular volume of air.
Define relative humidity
The amount of water air can hold at a specific temperature. It is relative compared to the amount of water the air at that same temperature can hold at 100 percent humidity or saturation.
Define Saturated air
When the air contains 100 percent of its capacity of water at a certain temperature.
Define Dew point temperature
The temperature at which water will condense from a particle of air.
Hot air is denser than cold air
False
explain what a hydrometer and psychrometer are for
To measure the relative humidity of the air in a room or outside.
What can cause static electricity, nose bleeds, dry throat, and dry skin?
Low humidity levels in a home/office.
What can cause you to feel cooler in a home or office?
Low humidity levels. - causes moisture in the body to evaporate, which uses heat energy
How does low humidity affect a building/structure and the things inside it?
Low humidity can cause cracking of wood, creaky floors, paper could dry out and crumble.
