Heat Loss Heat Gain Flashcards
What is the result of not balancing a house ?
House will have cold spots
What is the purpose of having air conditioning?
Provide high level of comfort
What are the 6 factors that must be addressed when selecting an air conditiong system
Noise
Temp
Humidity
Filtration
Circulation
Ventilation
Why is it important to complete a heat loss calculation on a residence ?
To ensure proper size of duct and equipment
What is the result of undersizing a heating system ?
Not enough warm or cold air for the area it’s providing and always running makeing it worn out faster and expensive
What is the result of oversizing a hvac system ?
Excessive cost and poor temp control
What is heat ?
Form of energy that flows between two body’s
When does Tempature not flow chop to cold ?
When temps are the same
What 4 factors affect a building environment ?
Building envelope
Occupants
Appliances
Mechanical systems
What separates the indoor from outdoor environment?
Foundation
Exterior walls
Windows
Doors
Vapour Barrie’s
Floors and ceilings
The building envelope reduces 3 losses from the outdoor environment. What are they ?
Radiative
Conductive
Convective
How much heat do occupants generate ?
250btuh
73 watts
What else adds heat to a building ?
Space heaters
Water heaters
Stoves
Fireplaces
Dryers
Lights
Can wind affect comfort ?
Yes
What are 3 methods of heat transfers ?
Conduction
Convection
Radiation
Where does heat transfer occur ?
Exposed walls above and below grade
Partitions
Windows and doors
Ceilings and floors
Infiltration
What is infiltration ?
How unconditioned air enters a conditioned space
What is effective Tempature ?
How a person feels at a set temperature
What is air temperature controlled by ?
Thermostat
Does a higher relative humidity percentage cause you to feel warmer or colder ?
Warmer
What is the outdoor winter design Tempature ?
72 degrees Fahrenheit in all living spaces
65 Fahrenheit in unconditioned basements
59 Fahrenheit in heated crawl spaces
What do we use for winter design conditons ?
January at 2.5
What is the design Tempature difference also know as delta t ?
The difference between indoor and outdoor design Tempatures
What is region adjustment ?
Value placed on a design temperature as a percentage
What are the three diffrent ways to calculate heat loads ?
Whole house loads
Floor by floor loads
Room by room loads
What’s the most accurate way to calculate heat loads ?
Room by room
What is htm and how is it calculated ?
A factor used to calculate the amount of heat energy transfers per square foot
Design temp difference divided by total resistance
What are 3 diffrent types of site exposure?
Unexposed
Partially exposed (means 2 or more sides exposed)
Fully exposed
What are the 3 different types of air tightness ?
Loose construction
Average construction
Tight construction
What is pickup for set back ?
Add an extra 10% to the heat loss calculation
What is definition of a gross wall exposed wall ?
Full length x full height including all penetrations
How do we calculate net exposed wall ?
Gross wall area minus doors and windows
What four things affect loads on a building in the summer when calculating heat gain ?
Solar radiation
Mass effect
Internal gains
Latent heat factors
What is the summer indoor design Tempature ?
75 degrees Fahrenheit
What is mass effect?
As building materials are heated by the sun they absorb the heat causing the Tempature to rise quickly
What are solar adjustments made to ?
Heat gain design tempatures
When must solar adjustments be made ?
If the mean Tempature range is greater than 15 degrees Fahrenheit or 8 degrees Celsius
