A
ACCA
Air Conditioning
Contractors of
America
AC or DC
Abbreviation for
equipment
capable of
operating on
alternating or
direct current.
A-Coil
A heat exchanger
consisting of
two diagonal
coils that are
joined together
in a manner that
looks like the
letter "A".
AFUE
Annual Fuel
Utilization
Efficiency. A
measure of a gas
furnace's
efficiency in
converting fuel
to energy - the
higher the
rating, the more
efficient the
unit.
AGA
Abbreviation for
American Gas
Association,
Inc.
Air Conditioner
Any device that
can change the
temperature,
humidity or
general quality
of the air.
Air cleaner
Any device that
removes
undesirable
particles from
moving air.
Air flow volume
The amount of
air the system
circulates
through your
home, expressed
in cubic feet
per minute (cfm).
Proper air flow
depends on the
outdoor unit,
the indoor unit,
the ductwork and
even whether the
filters are
clean.
Air handler
An air moving
and/or mixing
unit.
Residential air
handlers include
a blower, a
coil, an
expansion
device, a heater
rack and filter.
Heaters for air
handlers are
sold as
accessories. In
some models
heaters are
factory
installed.
ARI
Air Conditioning
& Refrigeration
Institute
ASHRAE
American Society
of Heating,
Refrigeration
and Air
Conditioning
Engineers
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B
BTU
British thermal
unit; the amount
of heat required
to raise or
lower the
temperature of
one pound of
water one degree
Fahrenheit. The
heat extracted
from your home
by an air
conditioner is
measured in
BTUs.
BTUh
British thermal
units per hour.
12,000 BTUh
equals one ton
of cooling.
Burner orifice
The opening
through which
gas flows to the
air/gas mixing
chamber of the
burner.
Burner (sealed
combustion)
A burner that
obtains all air
for combustion
from outside the
heated space.
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C
Capacity
The output or
producing
ability of
cooling or
heating systems.
Cooling and
heating
capacities are
referred to in
British thermal
units (BTUs) per
hour.
Celsius
The metric
temperature
scale in which
water freezes at
zero degrees and
boils at 100
degrees,
designated by
the symbol "C".
To convert to
Fahrenheit,
multiply a
Celsius
temperature by
9, divide by 5
and add 32 (25 x
9 equals 225,
divided by 5
equals 45, plus
32 equals 77
degrees
Fahrenheit).
CFM
Abbreviation for
cubic feet per
minute, a
standard
measurement of
airflow. A
typical system
requires 400 cfm
per ton of air
conditioning.
Charge
To add
refrigerant to a
system. This is
refrigerant
contained in a
sealed system or
in the sensing
bulb to a
thermostatic
expansion valve.
Climatuff®
CompressorThe
Trane Climatuff®
Compressor was
the world's
first successful
heat pump
compressor. To
this day it's
the only
compressor Trane
uses in its
residential
systems. It's
well known for
its superior
durability, its
low noise
levels, and high
efficiency.
Comfort-R ™ Coil
or Evaporator
Coil
A Trane Comfort
Coil is the
other, less
visible half of
your air
conditioning
system, and is
located inside
your home in the
indoor unit.
It's a tubing
coil in which a
volatile liquid
evaporates and
absorbs heat.
This is where
the refrigerant
evaporates as it
absorbs heat
from the indoor
air that passes
over the coil.
It serves as a
"heat
exchanger,"
moving heat into
your home in the
winter and away
from your home
in the summer.
Comfort-R ™
Airflow System
An exclusive
feature of a
high efficiency
home comfort
system from
Trane. This
method of
ramping airflow
gives you
greater humidity
control when
cooling and
provides warmer
air during
heating start
up.
Compressor
This is the
heart of an air
conditioning or
heat pump
system. It is
part of the
outdoor unit and
pumps
refrigerant in
order to meet
the cooling
requirements of
the system.
Condensate
Vapor that
liquefies due to
the lowering of
its temperature
to the
saturation
point.
Condenser coil
(or outdoor
coil)
In an air
conditioner, the
coil dissipates
heat from the
refrigerant,
changing the
refrigerant from
vapor to liquid.
In a heat pump
system, the coil
absorbs heat
from the
outdoors.
Condenser fan
The fan that
circulates air
over the
air-cooled
condenser.
Contactor
A switch that
can repeatedly
cycle, making
and breaking an
electrical
circuit. When
sufficient
current flows
through the
A-coil built
into the
contactor, the
resulting
magnetic field
causes the
contacts to be
pulled in or
closed.
Crankcase heater
This is the
electric
resistance
heater installed
on compressor
crankcases to
boil off liquid
refrigerant that
may have
combined with
compressor oil.
Many newer
cooling systems
do not require
crankcase
heaters, however
heat pumps do
require
crankcase
heaters.
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D
DC
Direct current
electricity.
This type of
electricity (as
opposed to
Alternating
Current, or AC)
flows in one
direction only,
without
reversing
polarity.
Damper
Found in
ductwork, this
movable plate
opens and closes
to control
airflow. Dampers
can be used to
balance airflow
in a duct
system. They are
also used in
zoning to
regulate airflow
to certain
rooms.
Defrost
To melt frost;
as in from an
air conditioner
or heat pump
coil.
Degree-day
A degree-day is
a computation
that gauges the
amount of
heating or
cooling needed
for a building.
A degree-day is
equal to 65
degrees
Fahrenheit minus
the mean outdoor
temperature.
Dehumidifier
An air cooler
that removes
moisture from
the air.
Diffuser
A grille over an
air supply duct
having vanes to
distribute the
discharging air
in a specific
pattern or
direction.
DOE
Department of
Energy
Downflow furnace
A furnace that
intakes air at
its top and
discharges air
at its bottom.
Drain pan
This also
referred to as a
condensate pan.
This is a pan
used to catch
and collect
condensate (in
residential
systems vapor is
liquefied on the
indoor coil,
collected in the
drain pan and
removed through
a drain line).
Dry bulb
temperature
Heat intensity,
measured by a
dry bulb
thermometer.
Dry bulb
thermometer
An instrument
that measures
air temperature
independently of
humidity.
Ductwork
A pipe or
conduit through
which air is
delivered. Ducts
are typically
made of metal,
fiberboard or a
flexible
material. In a
home comfort
system, the size
and application
of ductwork is
critical to
performance and
is as important
as the
equipment.
DX
Direct
expansion; a
system in which
heat is
transferred by
the direct
expansion of
refrigerant.
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E
EER
Energy
Efficiency Ratio
(steady state)
ENERGY STAR®
Trane high
efficiency
systems carry
the ENERGY STAR
label. The
result of
Trane's
partnership with
the U.S.
Department of
Energy,
Environmental
Protection
Agency (EPA),
ENERGY STAR
products are
more energy
efficient and
help reduce our
whole earth's
pollution
problems.
Choosing a Trane
ENERGY STAR
Comfort System
assures
homeowners of
lower energy
bills and
improved indoor
air quality for
their home.
EPA
Environmental
Protection
Agency
Expansion Valve
A
refrigerant-metering
valve with a
pressure or
temperature
controlled
orifice.
Evaporator coil
(or indoor coil)
The other half
of your air
conditioning
system located
inside your home
in the indoor
unit. This is a
tubing coil in
which a volatile
liquid
evaporates and
absorbs heat.
This is where
the refrigerant
evaporates as it
absorbs heat
from the indoor
air that passes
over the coil.
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F
Fahrenheit
The temperature
scale on which
water freezes at
32 degrees and
boils at 212
degrees;
designated by
the letter F. To
convert
Fahrenheit to
Celsius,
subtract 32 from
the Fahrenheit
number, multiply
by 5 and divide
by 9 (77 -32
equals 45, times
5 equals 225,
divided by 9
equals 25
degrees
Celsius).
Fan
Any device that
creates air
currents.
Filter
Any device that
removes
impurities
through a
straining
process.
Flue
Any vent or
passageway that
carries the
products of
combustion from
a furnace.
Furnace
That part of the
heating system
in which the
combustion of
fossil fuel and
transfer of heat
occurs.
Fuse
A metal strip in
an electrical
circuit that
melts and breaks
the circuit when
excessive
current flows
through it. The
fuse is designed
to break in
order to save
more expensive
electrical
components.
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G
GAMA
Gas Appliance
Manufacturers
Association
Gas Furnace Heat
Exchanger
Located in the
furnace, the
heat exchanger
transfers heat
to the
surrounding air,
which is then
pumped
throughout your
home.
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H
Heat Exchanger
An area, box or
coil where heat
flows from the
warmer to the
colder fluid or
surface.
Heat Gain
Heat added to
the conditioned
space by
infiltration,
solar radiation,
occupant
respiration and
lighting.
Heating Coil
Any coil that
serves as a heat
source.
Heat Loss
The rate of heat
transfer from a
heated space to
the outdoors.
Heat Pump
A
mechanical-compression
cycle
refrigeration
system that can
be reversed to
either heat or
cool the
controlled
space.
Heat Transfer
The movement of
heat energy from
one point to
another. The
means for such
movement are
conduction,
convection, and
radiation.
HEPA (High
Efficiency
Particulate Air)
cleaners also
use high
efficiency
pleated media to
remove
particles. To be
designated HEPA,
an air cleaner
must remove
99.97% of all
particles 0.3
microns in size
(such as dust
and mold
spores).
Due to high
cost,
operational
complications,
and other
problems, HEPA
units are
usually seen in
residential
applications as
one-room,
portable units,
When media in
theses units
need to be
replaced, it's
often relatively
expensive to do
so. Some require
charcoal filters
that need to be
cleaned
frequently.
Warranties for
HEPA cleansers
are normally one
to three years.
Hertz
In alternating
current (AC
electricity),
the number of
cycles per
second.
HSPF
Heating Seasonal
Performance
Factor. This
rating is used
in measuring the
heating
efficiency of a
heat pump. The
higher the
number the more
efficient the
heat pump
system.
Humidifier
A machine that
adds water vapor
to the air to
increase
humidity.
Humidistat
A
humidity-sensing
control that
cycles the
humidifier on
and off.
Humidity
The presence of
water vapor in
the air.
Humidity,
absolute
Weight of water
vapor per cubic
foot of dry air,
expressed as
grains of
moisture per
cubic foot.
Humidity,
relative
The amount of
moisture in the
air expressed as
a percentage of
the maximum
amount that the
air is capable
of holding at a
specific
temperature.
HVAC
Abbreviation for
Heating,
Ventilating and
Air Conditioning
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L
Latent Heat
A type of heat,
which when added
to or taken from
a substance,
does not change
the temperature
of the
substance.
Instead, the
heat energy
enables the
substance to
change its
state.
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N
NEC
National Energy
Council /
National
Electric Code
NEMA
National
Electrical
Manufacturing
Association
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P
Package Unit
A heating and
cooling system
contained in one
outdoor unit. A
package unit is
typically
installed
beside, on the
roof, or
sometimes in the
attic of a home.
PSI
Pounds per
square inch.
PSIA
Pounds per
square inch,
absolute.
PSIG
Pounds per
square inch
gauge.
PVC
Polyvinyl
chloride; a type
of plastic.
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R
Reciprocating
Compressor
A compressor
whose piston or
pistons move
back and forth
in the
cylinders.
Refrigerant
A chemical that
produces a
refrigerating
effect while
expanding and
vaporizing. Most
residential air
conditioning
systems contain
R-22
refrigerant.
R-22 is
regulated under
the Montreal
Protocol and in
the United
States by the
Environmental
Protection
Agency. R-22 is
scheduled to be
in production
until the year
2020. It's used
in approximately
95 percent of
air conditioning
equipment
manufactured in
the U.S. today.
Refrigerant
Charge
The required
amount of
refrigerant in a
system.
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S
SEER
Seasonal Energy
Efficiency
Ratio; a measure
of cooling
efficiency for
air conditioners
and heat pumps.
The higher the
SEER, the more
energy efficient
the unit.
Self-contained
System
A refrigerating
system that can
be moved without
disconnecting
any refrigerant
lines; also know
as a package
unit.
Sensible Heat
That heat which,
when added to or
taken away from
a substance,
causes a rise or
fall in
temperature.
Sensor
Any device that
reacts to a
change in the
conditions being
measured,
permitting the
condition to be
controlled.
Setpoint
The temperature
or pressure at
which a
controller is
set with the
expectation that
this will be a
nominal value
depending on the
range of the
controller.
Spine Fin™ Coil
All-aluminum
outdoor coil
that features
the patented
Spine Fin™
design. It
provides greater
heat exchanging
capabilities
(meaning higher
efficiencies)
and is more
resistant to
corrosion than
traditional
copper/aluminum
Split System
The combination
of an outdoor
unit (air
conditioner or
heat pump) with
an indoor unit
(furnace or air
handler). Split
systems must be
matched for
optimum
efficiency.
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T
Thermostatic
Expansion Valve
A refrigerant
metering device
that maintains a
constant
evaporator
temperature by
monitoring
suction vapor
superheat; also
called a thermal
expansion valve.
Thermostat
A thermostat
consists of a
series of
sensors and
relays that
monitor and
control the
functions of a
heating and
cooling system.
Ton
A unit of
measurement used
for determining
cooling
capacity. One
ton is the
equivalent of
12,000 BTUs per
hour.
Two-stage
heating /
Two-stage
cooling
Two-stage
heating and
cooling is
considered to be
more efficient,
because it
operates at low
speed most of
the time.
However, on days
when more
heating or air
conditioning is
required, it
switches to the
next stage for
maximum comfort.
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U
U-Factor
The factor
representing
resistance to
heat flow of
various building
materials.
UL
Underwriters
Laboratories
Upflow Furnace
A furnace in
which air is
drawn in through
the sides or
bottom and
discharged out
the top.
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V
Vacuum
A pressure below
atmospheric
pressure. A
perfect vacuum
is 30 inches
Mercury
(periodic symbol
"Hg").
Variable-speed
motor(s)
The fan motor
inside Trane's
variable-speed
air handlers is
designed to vary
its speed based
on your home's
heating and air
conditioning
requirements.
Working in
conjunction with
your thermostat,
it keeps the
appropriate-temperature
air (e.g. warm
air on cold
days)
circulating
throughout your
home, reducing
temperature
variances in
your home. It
also provides
greater air
circulation and
filtration,
better
temperature
distribution,
humidity
control, higher
efficiency, and
quiet
performance.
Volt
The unit of
measure used to
describe a
difference in
electrical
potential;
abbreviated by
the symbol "v".
Voltage
The force that
pushes
electrical
current along
wires and
cables.
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W
Watt
The unit of
electrical power
equal to the
flow of one amp
at a potential
difference of
one volt.
Wet Bulb
Thermometer
A thermometer
whose bulb is
covered with a
piece of
water-soaked
cloth. The
lowering of
temperature that
results from the
evaporation of
water around the
bulb indicates
the air's
relative
humidity.
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Z
Zoning System
A method of
dividing a home
into different
comfort zones so
each zone can be
independently
controlled
depending on use
and need; an air
conditioning
system capable
of maintaining
varying
conditions for
various rooms or
zones.
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