Chapter 17
for residential cooling applications, ___ Btu/hr of heat gain is used for appliances and cooking processes
1200
for a residence, the latent heat gain is ___% of the sensible heat gain
30
for residential cooling applications, heat gain from people is ___ Btu/hr of sensible heat per person with a latent heat allowance added
300
dimensions for windows and doors may be rounded to the nearest ____"
6
a summer indoor design temperature of ____ degree F is usually selected to provide comfort for a normally clothes person during summer
75
summer outdoor design temperatures are the warmest temperatures expected in an area during ____% of the summer
95
winter outdoor design temperatures are the coldest temperatures expected to occur in an area during _____% of the winter
97.5
in the ____ method, the volume of the building is found by multiplying the length times the width times the ceiling height of the building
air change
the ____ of the ceiling and floor is found by multiplying the dimensions of the rooms
area
for a residence, the number of people that occupy a building is determined by the number of ____
bedrooms
____ data is the name of each room, running feet of exposed wall, dimensions, ceiling height, and exposure of each room
building
____ load calculations are heating and cooling load calculations that are performed by a computer
computer-aided
____ is the opening around windows, doors, or other openings in a building such as between the foundation and framework of a building
crackage
a sketch of a residence contains the ___ required for calculating the heating and cooling load of the building
dimensions
the ___ factor is found by dividing the equipment capacity by the calculated load
equipment ratio
___ is the geographic direction a wall faces
exposure
for cooling load calculations, the area of windows and glass doors is calculated and entered on the form according to ____
exposure
___ are an example of a building components
exterior walls windows doors
variables and ____ are entered on a load form and are used to calculate heat losses and gains for a building
factors
a load calculation program requests different variables and factors than those used for a conventional load calculation
false
a winter indoor design temperature of 75 degrees F is usually selected to provide comfort for a normally clothes person during winter
false
all load application programs include heat loss for ductwork
false
five different methods are used to calculate the rate of infiltration of air into a building
false
heat gain through ductwork or piping is usually added in the load calculation
false
latent heat load for moisture in the air does not have to be considered in the cooling load, but it must be considered in the heating load
false
the distribution system for a job must be sized for the calculated load, not for the equipment output capacity
false
the information for the heating load is entered on the form first because more data is required for calculating heating loads than for cooling loads
false
the lighting load is calculated for a residential building because the lights are on when the cooling load occurs
false
the totals of a computer-aided load calculation should be within 1% of the totals taken from a reliable standard
false
when plans and specifications are not available for a building that is already built, the ___ of the building is sketched, and notes about the materials and construction methods are taken
floor plan
the ____ rate of infiltration air is the cooling load due to infiltration, but the actual cooling load is found on a psychrometric chart
flow
the ___ from people is not usually calculated in a heating load
heat gain
____ factors are used for calculating heat flow through individual components of a building
heat transfer
the air change method is based on the assumption that ___ air completely changes the air in a building
infiltrated
factors used in calculating heating and cooling loads include conduction factors, solar gain, ____ factors, and factors for heat produced by peoples, lights, and appliances
infiltration
most load calculating programs usually begin by requesting general information such as the ____, geographical location, and design temperatures
job
a ____ software program is a series of commands that requests data from the operator and manipulates the data to determine the heating and cooling loads
load calculation
design temperature is the temperature of the air at a ___ set of conditions
predetermined
to oversize heating and air conditioning equipment components, an equipment ___ factor is used
ratio
____ are written supplements to plans that describe the materials used for a building
specifications
the total loads from the computer program can be compared with a ___ for the type and location of the building or with a load calculated with the conventional method for a part of the building
standard
heat transfer is due to a ___ difference between the two sides of a material
temperature
Conventional load calculations are performed manually
true
because different factors are used for each load calculation method, there is usually some difference between computer-aided load figures and conventional load figures
true
design temperature difference is the difference between the indoor design temperature and the outdoor design temperature
true
ductwork and piping in cooling systems should always be insulated to reduce heat gain
true
gross wall area is calculated separately for each exposed wall of the building
true
hallways, closets, stairways, and other spaces in a building not part of a room or zone are included in the dimensions of adjacent rooms or zones
true
most commercial computer load calculation programs are written so a printout of the results shows subtotals of losses or grains for the rooms or zones in a building
true
most load calculation program instructions include a job information sheet
true
plans are drawings of a building that show dimensions, construction materials, location, and arrangement of the spaces within a building
true
since furnaces and air conditioners are manufactured in a limited selection of sizes, the equipment chosen for a job is usually oversized for the loads
true
the information for calculating the area of windows and glass doors is found on sketches or plans of a building
true
the net area of exposed walls is found by subtracting the area of windows and door from the gross exposed wall area for each room
true
the results of a computer load calculation program are assumed to be correct
true
to obtain the actual heating and cooling loads for a building, adjustments have to be made to totals
true
total heat loss or gain for a building is the sum of all the room or zone subtotals
true
when using a table of infiltration factors that is based on crackle, the total amount of crackle (in feet) is multiplied by the appropriate factor
true
if any part of the ductwork or piping system in a building runs through a ___ space, heat will be lost and will, therefore, be added to the heating load of the building
unconditioned
____ used in calculating heating and cooling loads include design temperature differences, area of building components, data for calculating infiltration or ventilation loss or gain, number of people occupying the building, and number of lights and appliances in the building
variables
using the air change method, the rate of infiltration of air into a building is calculated by multiplying the ___ of the building by a factor related to the number of times air change occurs per hour
volume
dimensions for ____ may be rounded to the nearest 6"
walls ceilings floors
gross wall area is the total wall area including ____
windows doors openings
