Heating And A/C Flashcards
An accumulator prevents what from entering the compressor?
Liquid refrigerant
A standard air conditioning system can easily be converted to a heat pump by the addition of a few key components. T/F
False
In a heat pump during the cooling cycle,which coil acts as the evaporator? In the heating cycle, which coil acts as the evaporator?
Indoor/outdoor
The _____ ______ directs hot refrigerant to the indoor coil in the _____ cycle in a heat pump .
Reversing valve
Heating
Under certain operating conditions,____ will form on the outdoor coil. This can cause a /an ______ in efficiency.
Frost
Decrease
The defrost cycle is initiated by ______ and _____.
Time and temperature
The most common cause of insufficient airflow in a A/C system is?
- Dirty coil
- dirty filter
Ductwork should be _____ enough to handle the volume of air needed for correct A/C operation.
large
In a heavy snowfall areas,it is good practice to mount the heat pump’s outdoor unit on a/an ____ to prevent snow from blocking The coil.
Elevated platform
Why are heat pumps labeled not to be operated unless power is on for a minimum if 12 hours ?
Oil in the compressor needs to be heated to remove liquid refrigerant
A non-technically exhaustive way to evaluate the heat exchanger?
Check flame pattern when the blower comes on
Which of the following statements is True for a cooling unit located In a attic where damage may result from condensate overflow?
A. Attic ventilation must be increased to avoid condensation
B. steel ducting is not allowed because of potential damage from condensation
C. A pan with a drain or float switch is required beneath the evaporator unit
D. A supplemental condensate pump is required
C. A pan with a drain or float switch is required beneath the evaporator unit
A furnace can be located in a laundry room? T/F
True
Converting a heating system fan to cooling type fan requires?
A 2 speed or variable speed fan
If a furnace had a pilot with a thermocouple . What device will most likely prevent the furnace from firing if it fails?
Thermocouple
An induced draft fan pulls air in what direction ?
Pulls through the furnace
Plastic (polyethylene) piping can be used for gas ? T/F
True
What is the purpose of a drip leg on a gas line?
- Traps sediment and metal chips
- traps water
What does an A/C compressor do?
Pressurizes the refrigerant gas in order to raise its temperature
Which part of the A/C cycle removes heat from The refrigerant ?
When it goes through the condenser
A heat pump system is primary sized for the?
Cooling load
The variation in temperature between the supply air and the return air in the A/C system should be approximately?
14-22 degrees
Oil tank-pipes from tank to burners
Must be protected from damage
How many sq per ton ac
500 sq ft
