Temperature, Humidity And Ventilation (110201e) Flashcards
What is heat?
Heat is a form of energy
( the ability to work)
What is a BTU?
British thermal unit the amount of heat required to raise the temperature of 55 cubic feet of air 1 degree Fahrenheit
What is cold?
Cold is the relative absence of heat
What is temperature?
Is the measure of the intensity of heat of a substance
What are the two laws of thermodynamics?
The first is that energy can neither be created nor destroyed
The second is that heat travels from a warm object to a colder one
What are four methods of heat transfer?
Conduction
Radiation
Convection
Latent heat of evaporation
What is conduction?
The transfer of a heat thorough a substance
What is convection?
The transfer of heat by natural motion
What is radiation?
The transfer of heat by energy waves similar to light waves
What is sensible heat?
Sensible heat is the heat required to change the temperature of a substance but not the state
What is latent heat?
Latent heat is the amount of heat required to change the state of a substance without changing its temperature
What is latent heat of evaporation?
Latent heat evaporation is the amount of heat required to change a liquid to a gas without changing its temperature
What is the specific heat of a given substance?
The numerous of btus required to raise the temperature of 1 pound of that substance 1 degree Fahrenheit
Humidity is defined as what?
The amount of water in the air
Dew point temperature is what?
The temperature that moisture will start to condense from the air
Relative humidity is what?
A measure of the amount of water air can hold at a certain temperature
What is a psychometric chart?
It is used by engineers in ac industry to determine values to properties of air
What effects does humidity have on structures?
Too much humidity will condense on windows and could cause ice build up
Different types of humidifiers are?
Pan style
Drum style
Disc wheel
Flow through
The main purpose of fresh air is?
Fresh air from outside the house is brought in to replace stagnant air caused by pollutants and oxygen depletion
A typical two fan HRV what do the fans do?
One fan removes exhaust air
The other fan brings in fresh air
The principal Ventilation fan is sized according to what?
Number of bedrooms
Some HRVs are capable of recovering what percentage of the heat of outgoing air?
85 percent
If a hot object is placed in a cooler liquid what will happen?
The hot object and cooler liquid will eventually become the same temperature
