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30 Cards in this Set
- Front
- Back
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HVAC equipment works together in residential or commercial systems to provide the proper temperature, humidity, circulation, filtration, and ventilation required for comfort
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Construction
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Humidifiers and dehumidifiers control the level of humidity in building spaces
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Construction
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Temperature stratification occurs when there is improper circulation in a building space
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Construction
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Supply and return air ductwork are sized and located to provide efficient flow of air through building spaces
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Construction
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Circulated air is cleaned by filters in heating and cooling equipment, or filters placed in the return air ductwork near the equipment
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Construction
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The best method of keeping the air in building spaces comfortable is to dilute the contaminated air by introducing fresh air from outdoors into the re-circulated (filtered) air
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Construction
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Energy conservation measures reduce the amount of outside air used in a building, which contributes to the buildup of indoor air contaminants
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Construction
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Normal building space requirement for fresh outside air (ventilation) is 20 cubic feet per minute per person in the space
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Construction
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Heat transfer factors are used for calculating heat flow through individual components of a building due to temperature differences
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Construction
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Total heat loss or gain for a building is the sum of all the room or zone subtotals
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Construction
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The areas of each of the rooms, windows and glass doors, other doors, net exposed wall area, ceilings, and floors in the building are entered on the load form
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Construction
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The factors for the heating load are found on a table of heat transfer factors. The factors for the cooling load are found on a table of cooling heat transfer factors
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Construction
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Total heat loss or gain for a building is the sum of all the room or zone subtotals
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Construction
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A forced-air distribution system consists of a blower, supply and return ductwork, registers, and grills
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Construction
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Friction loss occurs as air scrubs against the internal surfaces of a duct
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Construction
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A duct section is part of a distribution system between fittings where the air flow, direction, or velocity changes due to the configuration of the duct
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Construction
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A letter identifies each fitting and the duct section between fittings is identified by the fitting letters
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Construction
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A furnace is the central element in a forced-air heating system
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Construction
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Three common styles of furnaces are up-flow, horizontal, and downflow
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Construction
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Combustion and electricity are used to produce heat for furnaces
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Construction
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Propeller fans, centrifugal blowers, and axial-flow blowers are the three types of blowers used to move air in forced-air systems
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Construction
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Filters remove particulate matter from the air. The kind of filter used depends on air quality requirements.
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Construction
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An air distribution system consists of supply air ductwork, registers, return air ductwork, and grills.
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Construction
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Ductwork may be rigid or flexible depending on installation requirements.
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Construction
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Registers consist of a panel with vanes, a frame for mounting, and a damper for controlling airflow.
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Construction
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Disconnects in the electrical circuit to a furnace are located at the electrical service panel and on or near the furnace.
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Construction
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A transformer is used to change voltage from line voltage (120 V) to a lower voltage (24 V) for control systems.
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Construction
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A thermostat is a temperature-actuated electric switch that controls and operates the burner(s) or heating elements in a heating unit.
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Construction
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Limit switches shut a furnace OFF if the furnace overheats
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Construction
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A duct heater is located inside ductwork and uses air from a remote blower
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Construction
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