Air condition Flashcards
List 6 common evaporator problems.
- no access to coil
- dirty
- frost
- top of evaporator dry
- corrosion腐蚀
- damage
Oversized distribution分布 ductwork is a common problem with central air conditioning? True or False
False
An undersized air conditioner is better than an oversized one. True or False?
T
The typical temperature drop from outdoors to indoors with a properly operating air conditioning system would be about 15 degrees? True or False
T
What kind of temperature drop would you expect to find in the house air as it passes over the evaporator coil?
15-20
A compressor can be thought of as a pump? True or False
T
What is the function of a sump or crankcase heater?
It keeps the oil at the base of the compressor warm enough to boil off the refrigerant
List eight common compressor problems
- Excessive过度 noise/vibration震动
- Short cycling or running continuously
- Out of level
- Wrong fuse or breaker size
- Electric wires too small
- Missing electrical shut off
- Inoperative不工作
- Inadequate不足 cooling
The condenser coil in a split system is typically located________?
Outdoors
List three common configurations of evaporator coils
- A coil
- Slab Coil
- Vertical coil
Evaporator coils should be upstream of furnace heat exchangers. True or False.
False
In one sentence describe描述 the function of a capillary毛细管 tube
The capillary tube acts as an obstruction障碍物 in the line, reducing减少 the pressure and temperature of the liquid refrigerant制冷剂
In one sentence, describe描述 the function of a thermostatic恒温 valve.
A TXV, or TEV acts as a more precise精确的 expansion device on larger air conditioners调节器 or heat pumps.
List 4 common expansion device problems.
- capillary tube defect
- thermostatic expansion valve connections loose
- clogged orifice孔
- expansion valve 黏贴
List 7 possible causes of leaking condensate drip pans
- The pan may be cracked, or have an open seam in it
- The opening to the drain line may be obstructed堵塞
- The drain line may be missing or disconnected
- The pan may not be sloped properly allowing water to overflow rather than run to the drain
- The pan may be rusted through
- The pan may not be properly located below the coil
- The pan may be filled with debris碎片, restricting限制 the amount of water it can hold
When is an auxiliary辅助的 condensate冷凝 drain pan needed?
When the evaporator coil is located in an attic or anywhere over a finished living space.
What are condensate drain lines usually made of?
plastic or copper
Do condensate drain lines ever have a trap?
Condensate lines from the primary pan may or may not have a trap. Lines from secondary pans should never be trapped.
What is the purpose of a trap on a condensate drain line?
- The trap may be required if the condensate pan is upstream of the house air fan because the water is under negative pressure
- If the condensate is allowed directly into waste plumbing, a trap is required
List two acceptable discharge points for condensate drain lines and one generally unacceptable discharge point
Acceptable
- Outside the building directly into the ground
- Near the basement floor drain (must be an air gap)
Unacceptable
- Into the granular fill beneath the basement floor slab
- Into the waste plumbing stack
List three common condensate pump problems.
- Inoperative不工作
- Leaking
- Poor wiring
Refrigerant lines are usually made of________?
Copper
The larger line contains a liquid? True or false
False
The smaller line is called the suction line. True or False?
False
The smaller line is called the suction line. True or False?
False
The larger line is called the return line. True or False?
true
true
List 5 common refrigerant line problems
- leaking
- damage
- missing insulation
- lines too warm or cold
- lines touching each other
How would you normally identify识别 a leak in a refrigerant line visually?
This may be identified确定 by an oil residue残留 below the line set, typically at the valves or coil connections
Which line should be cold when the system is operating?
Suction line AKA return line (large insulated one)
Which line should be warm when the system is operating?
Liquid line (Smaller uninsulated line)
Which line should be insulated
Suction AK Return line
Where is the condenser fan in a split system located?
outdoors in the condenser unit
What is the typical inlet and outlet temperature of air across the condenser fan?
The inlet temperature is outdoor air temperature, and outlet temperature is roughlyd大约 15-20 degrees F higher than the outdoor temperature
Oversized ducts are a common problem. True or False?
False
Where is the evaporator fan typically located in a split system?
Indoors
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传统 furnace heat exchanger coil.
True or False
False
High level returns are more appropriate适当的 for heating than cooling. True or False?
False
Ducts passing through unconditioned spaces should as attics and crawlspaces should be ____________.
Insulated, with appropriate适当的 vapor barriers
How long do air conditioning compressors typically last in your area?
8-10 years southern USA
10-15 years Moderate climates
15-20 years Northern climates
What is the typical warranty period for a compressor?
typically 5 years
Heat pumps are generally sized based on the ?
Cooling load
The implication of an oversized heat pump during the summer month is?
It would cool the house down too fast without dehumidifying除湿 the air resulting in a cool damp environment客观环境.
You should not operate the heat pump in the heating mode when the outdoor temperature is above ________ degrees?
65
List 9 clues that would suggest that you are looking at a heat pump rather than da central air conditioning system
- Data plate may say “HP” or “Heat pump”
- Thermostat has an emergency heat setting
- Both refrigerant lines are insulated
- Presence of a reversing valve
- Compressor is indoors and it’s an air to air system
- Presence of an outdoor thermostat connected to control wiring
- If it is winter and the unit is operating its heat pump
- You find a two-stage thermostat
- You find two expansion devices
Common air conditioner thermostat problems include all of the following except?
Poor location
Not level
Loose
Wrong size
Which of the following is not a common problem with an air conditioner compressor?
Out of level
Excess超额 noise or 震动
Short cycling or running continuously
Overcooling the refrigerant制冷剂 in the condenser
Overcooling the refrigerant制冷剂 in the condenser
What is an evaporative cooler?
A unit that is a box shaped appliance with one or more porous多空 surfaces that enable air to pass through a fan inside the unit, Pulls outside air through the sides and into the house
What is the difference between a evaporative cooler and an air conditioner?
蒸发冷却器和空调有什么区别？
Evaporative coolers cool air by filtering it through water, thus lowering its temperature. Air conditioning works by taking the humidity out of the home
蒸发冷却器通过过滤水来冷却空气，从而降低其温度。空调的工作原理是把家里的湿气带走
What is the major advantage优势 of an evaporative蒸发 cooler?
Operating cost are typically 1/2 of a central Air conditioner.
how do you determine if the evaporator cooler is the correct size for the home?
Check to see if the motor is 1 or two speed
verify how many cubic feet of air per minute the cooler can pump and compare比较 that against how many cubic feet the home is.
