HVAC

Question 1

Refrigerant

Answer 1

The coolant run through a closed loop in a vapor-compression refrigeration cycle.

Question 2

Compressor

Answer 2

A pump that builds up pressure on one side of a system by forcing refrigerant through an expansion valve.

Question 3

Condenser

Answer 3

The high-pressure side downstream of the compressor that builds up liquid and releases heat.

Question 4

Evaporator

Answer 4

The low-pressure side of the cooling loop, downstream from the expansion valve, that converts liquid to gas and absorbs heat (releasing coolth)

Question 5

Expansion valve

Answer 5

Controls the release of pressurized liquid refrigerant into gas.

Question 6

Economizer

Answer 6

Bypassing the refrigeration cycle to use outside air or water for “free cooling”.

Question 7

Chilled beam system

Answer 7

A cooling radiator system where temps are slightly above dew point to avoid condensation.

Question 8

Delete

Answer 8

Must be kept slightly above the dew point in a chilled beam system.

Question 9

Split systems

Answer 9

HVAC systems that place the louder compressor and condenser outside.

Question 10

Manifold

Answer 10

Distribution pipe connecting multiple indoor units to a single outdoor unit.

Question 11

Mini split systems

Answer 11

Ductless, outdoor compressor/condenser, indoor air handler unit (evaporator).

Question 12

Swamp coolers (Evaporative Coolers)

Answer 12

Work well only when it’s very dry, making spaces more humid.

Question 13

VAV boxes (Variable Air Volume)

Answer 13

Allow 1 AHU to serve multiple zones using dampers.

Question 14

VAV with terminal reheat

Answer 14

Contains a heating element in the VAV box so some zones can be heated while others are cooled.

Question 15

VAV with fan unit

Answer 15

Pulls return air from the plenum back to mix with the supply air.

Question 16

Boiler

Answer 16

A hydronic heating system that heats water or another fluid.

Question 17

Hydronic

Answer 17

A system that heats water or another fluid to provide heating.

Question 18

Compression tank

Answer 18

Gives expanded, hot water somewhere to go without bursting pipes in a boiler system.

Question 19

AHU (Air Handling Unit)

Answer 19

Draws in air, conditions it, and blows it out.

Question 20

Dual Duct (delete)

Answer 20

A type of HVAC system.

Question 21

Chillers (delete)

Answer 21

A type of HVAC system.

Question 22

Cooling towers

Answer 22

Uses evaporative cooling before running water back to the compressor loop.

Question 23

Grille

Answer 23

Simple, damperless covers, usually for return air

Question 24

Register

Answer 24

Adjustable air volume control for supply with dampers

Question 25

Diffuser

Answer 25

Distribute air evenly in multiple directions

Question 26

Damper

Answer 26

Blades to stop or redirect air flow

Question 27

Variable Refrigerant Flow (VRF)

Answer 27

Uses a single outdoor condensing unit and multiple indoor evaporators with sophisticated controls.

Question 28

Heat Recovery Ventilator (HRV) / ERV

Answer 28

Recovers heat and/or humidity from exhaust air and transfers it to incoming fresh air.

Question 29

Fan Coil Unit (FCU)

Answer 29

A small terminal unit that uses a fan to blow air over a coil for local heating and cooling.

Question 30

Mufflers/silencers

Answer 30

Used to mitigate HVAC noise.

Question 31

Duct lining

Answer 31

The most effective method for mitigating noise, but it poses indoor air quality concerns.

Question 32

Hydronic Systems with 1, 2, or 4 pipes

Answer 32

1 pipe: everyone shares the same supply. 2 pipes: separate supply and return, but can only heat or cool at any point 4 pipes: heating and cooling can both run simultaneously