Cooling System Flashcards
_____ _____ _____ is a measurement of the amount of heat required to increase 1 lb of water by 1 degree F.
British Thermal Unit or BTU
_____ _____ _____ _____ is a measure of efficiency of a heat pump in heat mode shown by dividing the heating output by the energy used.
Heat Seasonal Performance Factor or HSPF
_____ _____ is the amount of water vapor that an air conditioner must remove from the air inside a house before the system can begin removing sensible load heat.
Latent load
The _____ _____ is the small, hot, high pressure copper tubing in a line set that is usually uninsulated. By contrast, the _____ _____ is the large, cool, low pressure copper tubing that is usually insulated.
Liquid line
Suction line
_____ or _____ is a refrigerant used in older systems that has been phased out and replaced with _____.
Freon or R-22
R-410A
_____ _____ _____ ______ is a measure of heat pump efficiency in cooling mode obtained by dividing the cooling output over a cooling season by the energy used. Minimum rating is currently _____ for most of the US.
Seasonal Energy Efficiency Ratio (SEER)
14
_____ _____ is the amount of heat energy that an air conditioning system must remove from the air inside a home due to air temperature.
Sensible load
_____ is a unit of measure of the size or cooling capacity of an air conditioning system equal to _____ BTU per hour.
Ton
12,000
_____ and _____ cooling systems are uncommon and are out of scope of a home inspection. _____ source and _____ source heat pumps are also out of scope. The inspector should report the presence, disclaim inspection, and recommend evaluation by a specialist.
Radiant and absorption
Ground source and water source
Liquid line temperature at the condenser should be a few degrees _____ than the outside temperature.
warmer
Standard efficiency air conditioning systems use metering devices called _____ _____ _____. Higher efficiency units use a ____ _____ _____.
thermostatic expansion valves (TXV or TEV)
electronic expansion valves (EEV)
One method of estimating how much heat is being removed from a house is by subtracting the difference in _____ between the ______ _____ and _____ _____ at the _____.
temperature
suction line
liquid line
Compressor
A heat pump is switched into heating mode when the _____ ______ is energized to _____ refrigerant flow.
reversing valve
reverse
In heating mode, the refrigerant leaving the air handler should be a few degrees _____ than inside temperature.
warmer
When a heat pump is in heating mode and the outside air temperature reaches around _____ degrees F, the system become inefficient and the _____ _____ are activated in the air handler to heat air.
30
heat strips
When a heat pump is operating in heat mode and operating near or below ______ degrees F, _____ may form on condenser fins causing the system to _____ flow momentarily to _____ the system.
32
frost
reverse
defrost
An air conditioning system that is too large may suffer from a condition called _____ _____, in which the system activates and deactivates too quickly. Since an air conditioner takes between ___ and ___ minutes to reach peak efficiency, this condition will cause increased operating costs. It will also prevent the system from performing _____.
Short cycling
10 and 20
Dehumidification
_____ calculation estimates the latent and sensible loads for a house.
Manual J
General rules dictate that a poorly insulated home with single pane windows requires _____ + BTU / 1,000 sq ft. A well insulated, air-tight home with multi-pane windows would only require _____ BTU / 1,000 sq ft. However, inspectors should be wary of using general rules to determine if a system is improperly sized because they often produce significantly _____ _____.
800
400
inaccurate results
The visual inspection of HVAC systems includes opening _____ _____ provided for _____ _____ and _____ and that are not _____ _____ _____. As a general rule, heat pump air handlers, evaporator coils, condensers, and package HVAC appliances _____ homeowner serviceable parts inside.
access panels
homeowner inspection
maintenance
sealed in place
do not have
Operating the air conditioner below __ degrees F risks the following: damaging the system by _____ ___ _____ , causing ____ to form in the evaporator coils, or obtaining _____ __ _____ test results.
60
slugging the compressor
ice
inaccurate or misleading
_____ _____ can be an inaccurate indicator of air conditioning system performance, even more so when the system is operating outside of normal _____ _____.
Temperature drop
operating temperatures
Ground and roof mount HVAC package systems should have a _____ to protect the ductwork. It should be _____ _____, _____, and _____. Roof mounted systems are usually supported on _____ _____ angle iron and _____ _____ to the roof.
shroud
corrosion resistant
intact
watertight
adequately secured
adequately secured
The typical service life of a condenser unit is approximately __ years, however one near a saltwater environment can be as short as __ years. The evaporator coil, furnace, and air handler have an expected service life of __ years or more.
15
5
20
HVAC components from different _____ should not be installed together. Inspectors should consider reporting the presence of such, and recommend evaluation to determine compatibility by an HVAC contractor.
manufacturers
Evaporative cooler water supply should be protected with a ______ prevention device.
backflow
Inspectors should report if an evaporative cooler has been left ____ or if the water supply is not protected by a _____ _____ _____. These systems are required to be mounted at least __ ft above or __ ft below contaminate air sources such as plumbing vents, appliance vents, and chimneys.
abandoned
backflow prevention device
10
3
Condenser model and serial numbers are usually located on a label near where the _____ _____ _____ enters the condenser.
refrigerant line set
When measuring _____ _____ in air conditioners, the measurement error is too great to make measuring at _____ and _____ _____ useful. The ideal place is the _____ and _____ _____ at least __ in away from the evaporator coil.
temperature drop
supply and return registers
supply and return plenums
12
Minimum finished attic access opening size is __ by __ in. Minimum finished crawl space access opening is __ by __ in. Appliances in attics and crawl spaces should be located within __ ft of the access opening and provided a _____ service space at least __ by __in for all sides of the appliance that require service. A __in wide passageway covered by floor sheathing should lead from the access opening to the service space.
20x30
22x30
20
level
30x30
24
In a humid climate, a temperature drop measured in a cooling system between __ and __ degrees F is considered normal by most inspectors. In a dry climate, numbers between __ and __ degrees F are considered normal. However these numbers can vary and inspectors _____ report that a “normal” temperature drop indicates the system is operating as intended.
15 and 20
18 and 24
should not
Manufacturers commonly require that condenser units have at least __ in of clearance in front of the service access, __ to __ in on the sides, __ in above, in addition to the bottom being located at least __in above grade.
30
6 to 12
48
3
Condenser units required at least __ ft clearance to clothes dryer exhaust vents.
3
Most manufacturers require the indoor unit of a mini-split system to be installed a minimum of __ to __ ft above the finished floor.
5-6
The evaporator coil creates a significant amount of water from condensation, which must be sent to an appropriate place for _____. This usually accomplished via a _____ _____ _____ that is at least ____ in diameter and must slope at least _____ in per foot towards the disposal point. Some jurisdictions in warm/humid climates require the pipe be _____.
disposal
condensate disposal pipe
3/4
1/8
insulated
A _____ _____ _____ _____ is required if the evaporator coil is located where condensate could damage nearby materials, which is usually anywhere inside a home. Usually, a _____ is placed under the evaporator coil which is at least ___ in deep and extends at least ___ in beyond the evaporator on all sides. The _____ is usually drained to the outside in the same manner as the primary disposal pipe.
Auxiliary condensate management system
Pan
1 1/2
3
Pan
Another auxiliary system in dealing with condensate, a _____ ______ ______ _____ may be installed in either the evaporator as an auxiliary system or in the pan to support the auxiliary system. This will cause the air conditioner to ___ ___when condensate is blocked at either point.
Water level shutoff switch
Shut off
Most manufacturers recommend a maximum of __ ft spacing between supports for refrigerant line set. The line set should not _____ or ____. Supports should be compatible with ____ to avoid _____.
8
sag or crimp
copper
corrosion
Maximum line set distance is __ ft and maximum vertical distance is __ ft to avoid issues with _____. These distances are less for _____ _____ systems.
60
25
efficiency
mini-split
_____ _____ insulation should be intact over the entire length of the line set. The _____ _____ may require insulation in areas where attic is extremely hot. Line set may be buried if _____ in a _____ _____ _____. Line set penetration into house should be ______.
suction line
liquid line
enclosed
protective pipe sleeve
sealed
_____ thermostats should be level to avoid inaccurate operation. Digital thermostats use a _____ to measure temperature and should be _____ however being level is less important.
analog
thermistor
secure
The best location for a thermostat is in a _____ near a _____. It should not be located near _____ registers, _____, or other _____ or cooling sources. Do not place them near _____, _____, _____, or where _____ will _____ on the thermostat.
hallway
return
supply
radiators
heating
windows, exterior doors, exterior walls
sunlight will shine
Thermostats operate on _____ voltage, such as __ or __ volts. Splices or connections _____ required to be covered in a box, but the thermostat cable must have a _____ where it enters a metal enclosure.
low
12 or 24
are not
grommet/bushing
A room facing south or west often requires a _____ duct for cooling than a room facing north or east. Inadequate duct size is a common reason for _____ _____ _____ between rooms.
larger
temperature balancing problems
_____ _____ installation is another reason for temperature balancing problems. Problems that could result include comfort complaints, increased HVAC system _____ _____ and _____, reduced _____ _____, and _____ control problems.
improper duct
operating time and cost
service life
moisture
Direction changes in ductwork should be planned and accounted for in the _____ calculations and implemented using appropriate _____ and technique.
Manual D
fittings
Poor planning in ductwork may result in _____ _____ from a straight line resulting in _____ bends, _____ of duct size, and _____ ducts.
unplanned deviations
sharp
constriction
sagging
Preferably, _____ _____ _____ should be along exterior wall near a window. _____ _____ _____should be located in the opposite vertical direction to assist air circulation. _____ and _____ can help reduce the impact of less than ideal supply and return air locations.
supply air registers
return air inlets
registers and diffusers
Rooms with doors that can be closed, namely bedrooms, should have a method of allowing _____ _____ that enters the room to _____ to the HVAC system, which is usually accomplished by installing _____ or _____ that connect the room to a central hallway return. These are often referred to as _____ or ______.
supply air
return
ducts or grilles
transfers or jumpers
A multiple story house with only one HVAC system will often be _____ on one story and _____ on the other. _____ _____ _____ may help, but likely will not completely solve the issue. Lack of separate HVAC systems for each story is not necessarily a deficiency, however the inspector should comment about ______ _____ _____ in such houses.
hotter
colder
thermostat controlled dampers
temperature distribution problems
_____ _____ and _____ _____ _____ were commonly used as return plenums in homes, however this is no longer allowed in new homes. Cavities may not be used for _____ plenums and cavities on _____ walls, or those used in a _____ ______ assembly are excluded from either use.
stud wall and floor joist cavities
supply
exterior
fire resistant
Flex duct should be supported by at least __ in wide material every __ ft horizontally and every __ ft vertically. It should also be supported within __ ft or or 1 duct diameter, whichever is smaller, of both sides of all bends and fittings.
1 1/2
4
6
1
Flexible ducts should not sag more than __ in per foot in length.
1/2
_____ should be supported independently from ducts.
Plenums
Sheet metal ducts should be supported by at least __ in wide metal wire or straps at least every __ ft.
1/2
10
Duct board should be supported by __ in wide material at least every __ to __ ft.
1 1/2
6 to 8
Supply duct leakage reduces _____ and _____ _____ to rooms while increasing system _____ _____.
efficiency
air flow
operating costs
Return duct leakage can introduce _____ such as _____, _____, and _____ into the HVAC system and into the house.
contaminants
dust, fungus, vermin
_____ tape is NOT an approved method for sealing joints in ducts. Approved methods include _____, _____ _____and _____ _____ _____ _____.
duct
gaskets
mastic tape
pressure sensitive foil tape
Sheet metal ducts are secured with _____ or _____ _____, while flexible ducts are usually secured to duct collars and splicing sleeves with _____ or _____ _____.
screws
pop rivets
straps
zip ties
A 90 degree bend in flex duct can effectively add __ ft of length to a duct in terms of airflow.
20
The radius of a bend in flex duct should be greater than or equal to the _____ of the duct, which equates to a maximum duct bed of __ degrees. Flex duct should not bend over or around _____ such as _____ _____.
diameter
90
obstructions
framing members
_____ _____ _____ allow one HVAC system to supply air to multiple zones or floors of the house.
Thermostat-controlled dampers
Air pressure differences caused by multi-zone HVAC systems can be resolved by a _____ _____ between the _____ and _____ _____ containing a _____ _____ that will open and close to equalize the pressure in the system as needed.
jumper duct
supply and return plenums
barometric damper
Flex duct should be spliced together using a _____ _____ _____ and a duct should not be inserted into _____ _____.
sheet metal sleeve
another duct
Ducts should be installed at least __ in above soil.
4
_____ or _____ on supply registers is an indication of high humidity in the house.
Significant condensation or rust
_____ should not be installed on return air ducts.
Dampers
An HVAC system that serves the house should not have any _____ or _____ in the garage. A system that serves only the garage may only have ducts made of _____ _____.
ducts or openings
sheet metal
Since _____ _____ _____ will degrade system efficiency and performance, inspectors may consider removing _____ _____ _____ before conducting a _____ _____ measurement.
insufficient return air
extremely dirty filters
temperature drop
Return air should not be taken directly from ___, ___, ___, ___, ___, ___, or ___.
closets, bathrooms, toilet rooms, kitchens, garages, furnace/boiler rooms, unconditioned attic/crawl space
Return inlets located near fuel burning appliances may contribute to _____ of _____ _____ and should not be located in the same room within ___ ft of the appliance.
backdrafting of combustion gases
10
Mesh return filters should be changed _____ and paper filters may need to be changed _____ _____ than is ______ on the _____.
monthly
more frequently
implied on the packaging
Return filters should not be located in a return boot at the _____ _____ or _____.
air handler or furnace
