Home inspection ch. 12 Air Conditioning and Heat Pumps

List 9 clues that would suggest that you are looking at a heat pump rather than da central air conditioning system

1. Data plate may say "HP" or "Heat pump" 2. Thermostat has an emergency heat setting 3. Both refrigerant lines are insulated 4. Presence of a reversing valve 5. Compressor is indoors and it's an air to air system 6. Presence of an outdoor thermostat connected to control wiring 7. If it is winter and the unit is operating its heat pump 8. You find a two-stage thermostat 9. You find two expansion devices

List eight common compressor problems

1. Excessive noise/vibration 2. Short cycling or running continuously 3. Out of level 4. Wrong fuse or breaker size 5. Electric wires too small 6. Missing electrical shut off 7. Inoperative 8. Inadequate cooling

List seven common problems with thermostats

1. Inoperative 2. Poor location 3. Not level 4. Loose 5. Dirty 6. Damaged 7. Poor adjustment/calibration

List three common condensate pump problems.

1. Inoperative 2.Leaking 3.Poor wiring

List 11 items that affect the amount of air conditioning needed in a home

1. Outdoor temperature 2. Outdoor humidity 3. Insulation level in the house 4. Single, Double, Triple pane windows 5. Whether windows are low 6. Whether window coverings are open 7. Amount of shading from trees 8. Roof overhang 9. Awnings or buildings nearby 10. Amount heat generated inside by people and equipment 11. Amount of east and west facing glass

List 7 possible causes of leaking condensate drip pans

1. The pan may be cracked, or have an open seam in it 2. The opening to the drain line may be obstructed 3. The drain line may be missing or disconnected 4. The pan may not be sloped properly allowing water to overflow rather than run to the drain 5. The pan may be rusted through 6. The pan may not be properly located below the coil 7. The pan may be filled with debris, restricting the amount of water it can hold

List 4 common expansion device problems.

1. capillary tube defect 2. thermostatic expansion valve connections loose 3. clogged orifice 4. expansion valve sticking

List 5 common refrigerant line problems

1. leaking 2. damage 3. missing insulation 4. lines too warm or cold 5. lines touching each other

List 6 common evaporator problems.

1. no access to coil 2. dirty 3. frost 4. top of evaporator dry 5. corrosion 6. damage

List three common configurations of evaporator coils

1.A coil 2.Slab Coil 3. Vertical coil

List four condenser problems

1.Dirty 2. Damaged or leaking 3.Corrosion 4.Dryer or water heater exhaust too close

What is the purpose of a trap on a condensate drain line?

1.The trap may be required if the condensate pan is upstream of the house air fan because the water is under negative pressure 2. If the condensate is allowed directly into waste plumbing, a trap is required

What kind of temperature drop would you expect to find in the house air as it passes over the evaporator coil?

15-20 degrees

How many square feet can 1 ton of air conditioning cool in Florida?

450-700

You should not operate the heat pump in the cooling mode when the outdoor temperature is above _________ degrees?

65

You should not operate the heat pump in the heating mode when the outdoor temperature is above ________ degrees?

65

How many square feet can 1 don of air conditioning cool in Michigan?

700-1000

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

In one sentence, describe the function of a thermostatic valve.

A TXV, or TEV acts as a more precise expansion device on larger air conditioners or heat pumps.

What is an evaporative cooler?

A unit that is a box shaped appliance with one or more porous surfaces that enable air to pass through a fan inside the unit, Pulls outside air through the sides and into the house

List two acceptable discharge points for condensate drain lines and one generally unacceptable discharge point

Acceptable 1. Outside the building directly into the ground 2. Near the basement floor drain (must be an air gap) Unacceptable 1. Into the granular fill beneath the basement floor slab 2. Into the waste plumbing stack

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 that against how many cubic feet the home is.

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.

Heat pumps are generally sized based on the ?

Cooling load

Refrigerant lines are usually made of________?

Copper

What is the difference between a evaporative cooler and an air conditioner?

Evaporative coolers cool air by filtering it through water, thus lowering its temperature. Air conditioning works by taking the humidity out of the home

Compressors are typically located indoors on an air-to-air split system air conditioning system. True or False?

False

Evaporator coils should be upstream of furnace heat exchangers. True or False.

False

High level returns are more appropriate for heating than cooling. True or False?

False

Oversized distribution ductwork is a common problem with central air conditioning? True or False

False

Oversized ducts are a common problem. True or False?

False

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. True or False

False

The larger line contains a liquid? True or false

False

The smaller line is called the suction line. True or False?

False

Where is the evaporator fan typically located in a split system?

Indoors

The evaporator coil in a split system is typically located _____________?

Indoors (above the Furnace)

Ducts passing through unconditioned spaces should as attics and crawlspaces should be ____________.

Insulated, with appropriate vapor barriers

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

The implication of an oversized heat pump during the summer month is?

It would cool the house down too fast without dehumidifying the air resulting in a cool damp environment.

Which line should be warm when the system is operating?

Liquid line (Smaller uninsulated line)

What is the major advantage of an evaporative cooler?

Operating cost are typically 1/2 of a central Air conditioner.

The condenser coil in a split system is typically located________?

Outdoors

The condenser fan in a split system is located _________?

Outdoors

Which of the following is not a common problem with an air conditioner compressor? Out of level Excess noise or vibration Short cycling or running continuously Overcooling the refrigerant in the condenser

Overcooling the refrigerant in the condenser

Which line should be insulated

Suction AK Return line

Which line should be cold when the system is operating?

Suction line AKA return line (large insulated one)

In one sentence describe the function of a capillary tube

The capillary tube acts as an obstruction in the line, reducing the pressure and temperature of the liquid refrigerant

Which of the following is not a common problem with a condensate collection system on a split system air conditioner? The condensate goes into a 3/4 In drain pipe The pan is leaking The drain is blocked There is no trap

The condensate goes into a 3/4 in drain pipe

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 roughly 15-20 degrees F higher than the outdoor temperature

How would you normally identify a leak in a refrigerant line visually?

This may be identified by an oil residue below the line set, typically at the valves or coil connections

A compressor can be thought of as a pump? True or False

True

An undersized air conditioner is better than an oversized one. True or False?

True

The typical temperature drop from outdoors to indoors with a properly operating air conditioning system would be about 15 degrees? True or False

True

When is an auxiliary condensate drain pan needed?

When the evaporator coil is located in an attic or anywhere over a finished living space.

Where is the condenser fan in a split system located?

outdoors in the condenser unit

What are condensate drain lines usually made of?

plastic or copper

The larger line is called the return line. True or False?

true

What is the typical warranty period for a compressor?

typically 5 years

Common air conditioner thermostat problems include all of the following except? Poor location Not level Loose Wrong size

wrong size