Terminology

Question 1

What does an Air-Cooled system mean and what are some examples?

Answer 1

Any refrigeration-based cooling system that rejects heat to the outdoors via a dry condenser coil and condenser fan. Examples include air-cooled chillers, package units, split systems or VRF system

Question 2

Air Handling Unit (AHU) components

Answer 2

Supply fan, cooling coil, filters, and possibly return fan, economizer section, heating coil, humidifier and integral sound traps.

Question 3

Air Separator

Answer 3

A device in a closed loop hydronic system to remove unwanted air

Question 4

Air Terminal

Answer 4

A grille, register or diffuser.

Question 5

Blow Through Unit

Answer 5

An AHU or FCU with the supply fan located upstream (BEFORE) the coils.

Question 6

Chemical Pot Feeder

Answer 6

A small tank, typically 5 gallons, used in closed loop hydronic systems to manually add water treatment chemicals on a periodic basis

Question 7

What is a Chilled Water system

Answer 7

A cold water system that allows cooling energy to be distributed throughout a building.

Question 8

Chiller

Answer 8

A piece of equipment with an internal refrigeration cycle used to make cold water.

Question 9

What is a Cooling Tower?

Answer 9

A piece of equipment that rejects heat to the outdoors, used in water-cooled systems.

Question 10

Condenser Water

Answer 10

The water system that allows heat to be rejected from cooling equipment

Question 11

Condensing Unit

Answer 11

The outdoor unit in a split system, which typically contains a condenser coil, condenser fan, and compressor.

Question 12

Diffuser

Answer 12

A device for delivery of supply air to a space.

Question 13

Displacement Ventilation

Answer 13

An air distribution concept where cool air is supplied into the occupied space at low level, thereby displacing warmer room air. Return air is removed from the space at a high level.

Question 14

Examples of Displacement Ventilation

Answer 14

Underfloor air distribution, with low-level sidewall diffusers, or via integral seat or step diffusers in theaters or similar spaces with fixed seating.

Question 15

Dual Duct System

Answer 15

An older type of system sometimes found in existing buildings whereby cold and warm air are distributed throughout the building separately in two ducts to each zone. More modern approach is VAV RH Systems

Question 16

Draw Through Unit

Answer 16

An air handling unit or fan coil unit with the supply fan located downstream (AFTER) the coils.

Question 17

Economizer (Air Side)

Answer 17

Provide free cooling to a building whenever the outdoor air temperature is cool enough.

Question 18

Economizer (Waterside)

Answer 18

Provide free cooling in a water-cooled chiller system by using the cooling tower to generate cold water when outdoor conditions are cold enough skipping the chiller.

Question 19

Expansion Tank

Answer 19

A device in a closed loop hydronic system to allow for the normal expansion and
contraction of water as it changes temperature.

Question 20

Fan Coil Unit (FCU)

Answer 20

small HVAC unit to supply conditioned air consisting of a fan, coil and filter.
Various types include chilled water, DX, heating water, and four-pipe

Question 21

Fan Powered Box

Answer 21

A terminal unit with a small integral fan. Used in cold climates to handle spaces with high heating loads. The fan allows plenum return air to be mixed with the primary air. Supply airflow is increased and allows heating load to be satisficed with a supply air temp that isn’t too hot.

Question 22

Fire Smoke Damper (FSD)

Answer 22

A damper that is open during normal operation and closes when needed to stop the spread of fire or smoke.

Question 23

Four-pipe

Answer 23

An HVAC system or unit with chilled water and heating hot water. There is no duct for supply air.