ICA Module 2 Section 2 Air Conditioning Flashcards
List at least 10 items that affect the amount of air-conditioning needed in a home
outdoor temp, outdoor humidity, level of insulation in home, air gaps, how many panes are in windows
How many square feet can 1 ton of air-conditioning cool in Florida?
450-700 sqft
How many square feet can 1 ton of air-conditioning cool in Michigan?
700-1000 sqft
Oversized distribution ductwork is a common problem with central air-conditioning. T/F
False
An undersized air conditioner is better than an oversized one. T/F
True
The typical temperature drop from outdoors to indoors with a properly operating air-conditioning system would be about 15 degrees F. T/F
True
What kind of temperature drop would you expect to find in the house air as it passes over the evaporator coil?
15 degrees
A compressor can be thought of as a pump. T/F
True
Compressors are typically located indoors on an air-to-air split system air-conditioning system. T/F
False
What is the function of a sump or a crankcase heater?
Keeps oil warm enough to boil off refrigerant
List 8 common compressor problems.
excess noise, short cycling, not level, wrong breaker size, not cooling, not working
The condenser coil in a split system is typically located ___.
in cabinet (condenser unit)
The evaporator coil in a split system is typically located _____.
just past furnace heat exchanger
The condenser fan in a split system is located _____.
in front of compressor & condenser coil
List 4 condenser-coil problems.
dirty, damaged, corrosion, dryer exhaust too close
List 3 common configurations of evaporator coils.
A coil, N coil, Slab coil
Evaporator coils should be upstream of furnace heat exchanges. T/F
False
List 6 common evaporator problems.
no access to coil, dirty, frost, damage, corrosion
In one sentence, describe the function of a capillary tube.
expansion device
In one sentence, describe the function of a thermostatic expansion valve.
metering device
List 4 common expansion device problems
capillary tube defects, loose, clogged, sticking
List 5 possible causes of leaking condensate drain pans
rust, cracks, dirt accumulation, improper slope
When is an auxillary condensate drain pan needed?
above finished living space
What are condensate drain lines usually made of?
plastic, copper
Do condensate drain lines ever have a trap?
Yes
What is the purpose of the condensate trap?
use weight of water to stop the flow of air (like a P-trap)
List 2 acceptable discharge points for condensate drain lines & 1 generally unacceptable discharge point.
Acceptable=sink, floor drain
Not Acceptable=through floor (slab)
List 3 common condensate pump problems
not working, leaking, poorly wired
Refrigerant lines are usually made of ___
copper
The larger refrigerant lines contains a liquid T/F
False
The smaller refrigerant line is called the suction line. T/F
False
The larger refrigerant line is called the return line. T/F
True
List 5 common refrigerant line problems.
leaking, damage, missing insulation, too warm/cold, too c?
How would you normally identify a leak in a refrigerant line visually?
oil residue
Which line should be cold when the system is operating?
suction/return line (large line)
Which line should be warm when the system is operating?
liquid line (small line)
Which line should be insulated?
suction line (large line)
Where is the condenser fan in a split system located?
condenser cabinet
What is the typical inlet & outlet temperature of air across the condenser fan?
20 & 50 degrees
List 4 common condenser-fan problems.
noisy, not working, corrosion, obstructed air flow
Where is the evaporator fan typically located in a split system?
inside air handler (inside house)
The amount of air that must cross an evaporator coil in a heating climate is less than the amount of air that must cross a conventional furnace heat exchanger coil. T/F
?
Oversized ducts are a common problem. T/F
False
High-level returns are more appropriate for heating than cooling. T/F
False?
Ducts passing through unconditioned spaces such as attics or crawlspaces should be _____.
insulated & air tight
List 7 common problems with thermostats
not working, loose, dirty, damaged, not level, poor location
How long do air-conditioning systems typically last in your area?
10-15 years
What is the typical warranty period for a compressor?
10 years
Heat pumps are generally sized based on:
A. heating load
B. cooling load
C. other
A-heating load (capacity)
The implication of an oversized heat pump during the summer months is what?
damp climate indoors
You should not operate the heat pump in the heating mode when the outdoor temperature is above _____.
65 degrees
You should not operate the heat pump in the cooling mode when the outdoor temperature is below _____.
65 degrees
List at least 8 clues that would suggest that you are looking at a heat pump rather than a central air-conditioning system.
data plate, if thermostat has emergency heat setting, 2 stage thermostat, both lines are insulated, reversing valve present, 2 expansion devices, compressor indoors, outdoor thermostat, operated in winter
List 7 common heat pump problems distinct from common air-conditioning problems.
oversized for cooling/undersized for heating, inoperative, poor control coil location, coil iced up, air flow problems, no back up heat, old
