1060 WeekF (CH72)
What is the HTM for a surface with a U valve of 1.5 and a temperature difference of 30?
45
Compared to a system in an area with a low daily temperature range,a system in an area with a high daily temperature range would require:
A little less cooling capacity.
A load study that calculates the load for each individual room as well as the entire house is called:
A room-by-room load calculation.
What type of load study is recommended for duct design?
A room-by-room load study
A load study that treats the whole house as one big room is called:
A shell load calculation.
What is an opaque surface?
A surface that light cannot pass through, such as walls
What is the most common residential load calculation that is accurate?
ACCA Manual J
How is a U factor calculated for a building panel built of several different materials?
Add the R values of the different materials and then find the reciprocal.
In Manual J, fenestration means:
Anything that light can pass through.
What effect does the daily range have on heat gain?
Areas with a high daily range can take advantage of natural cooling that occurs at night, so the cooling HTMs can be a little smaller.
Infiltration calculations in Manual J8 are based on:
Estimates of air changes in the house.
To improve humidity control for air-conditioning systems installed in humid climates, the air-conditioning system selected should:
Have a high latent cooling capacity and not be oversized.
What is sensible heat gain?
Heat gain that causes the air temperature in the house to increase
What is latent heat gain?
Heat gain that results from increased moisture in the air in the house
What is the difference between heat loss and heat gain?
Heat loss occurs in the winter, and heat gain occurs in summer.
What is the difference between infiltration and ventilation?
Infiltration is air that leaks, while ventilation is drawn in on purpose.
In selecting the outside cooling design conditions for Manual J8, a temperature is chosen for each area that:
Is exceeded 1% of the year.
In selecting the outside heating design conditions for Manual J8, a temperature is chosen for each area that:
Is exceeded 99 percent of the year.
Oversized equipment operates:
Less efficiently than correctly sized equipment.
The largest loads in commercial heat gain calculations include heat gain from:
Lights, people, machinery, and ventilation.
For purposes of Manual J8 tables, daily temperature ranges are normally listed as:
Low, medium, and high.
The two types of load calculations outlined in Manual J8 are:
Peak load procedure and average load procedure.
How is the R value determined for a composite structure, such as a wall?
The R values of all the individual components are added together.
Why is the cooling temperature difference often different from the difference between the indoor and outdoor temperatures?
The cooling temperature difference takes heat storage and daily temperature range into account.
What is meant by the temperature daily range?
The daily range is the difference between the average high and the average low temperatures during the day.
Solar heat gain is considered when calculating:
The heat gain of the windows.
The grains of moisture difference in the weather data tables are used for calculating:
The latent heat gain
The grains of moisture difference in the weather data tables are used for calculating:
The latent heat gain.
How is an HTM calculated?
U value times the temperature difference
