SYSTEMS: Thermal, HVAC, Plumb, Elec, Acoustics, Lighting,

Question 1

cold or warm

Coolant that is evaporating is … ?

moving from liquid to gas

Answer 1

Cold

this process is TAKING heat

Question 2

cold or warm

Coolant that is condensing is … ?

moving from gas to liquid

Answer 2

Warm

when a gas condenses into a liquid, heat is released.

Question 3

Liquids change to gas under what type of pressure?

Low or High

Answer 3

Low Pressure

Lower pressure ‘pulls’ the molecules apart.

Question 4

High pressure has what affect on gases?

Answer 4

It condenses them to liquid form.

Question 5

Economizer Cycle

Answer 5

An efficiency mode used when inernal load dominated bldgs still need cooling despite cold temperatures outside.

Question 6

Name and describe the two types of economizer cycles.

Answer 6

1. Water-Side Economizer: uses water chilled outside in a cooling tower, and cycles it across coolant pipes. The cold coolant causes the valve to open, eliminating pressure and allows cold coolant to flow freely throughout the system.
2. Air-Side Economizer: allows cold outside air to be brought into the bldg through the filtered air handler.

Question 7

How does a heat pump work?

Answer 7

Coolant flows through pipes, and air is blown acoss said pipes to distribute hot or cold air. To switch between hot and cold coolant, the flow is simply reversed.

Question 8

How does a geothermal heat pump work?

Answer 8

It uses the earth’s constant 55 deg temp to heat or cool pipes of water that helps the outdoor coils filled with coolant either evaporate or condense depending on the season.

Question 9

What five factors should you use to come up with HVAC zones?

Answer 9

1. Occupancy
2. Sun Exposure
3. Air Quality
4. Schedule
5. Core vs Permieter

Question 10

What two terms do we use for vents that supply air?

Answer 10

1. Diffuser, kind of like a target that spread air all around.
2. Register, grates in the floor or wall.

Question 11

What term do we use for return air vents?

Answer 11

Grille

Question 12

What does terminal reheating do in an HVAC system?

Answer 12

It gives systems with single air handling units the ability to heat one zone while cooling another by reheating cooler air at the VAV box.

This is very energy inefficient.

Question 13

How much is 1 Ton of cooling in Btu/hr?

Answer 13

1 Ton cooling = 12,000 BTU/HR

Question 14

Which of the following can be used most effectively to limit low-frequency sounds in an HVAC system?

Answer 14

NCARB - Duct liners, but mufflers also help.

Question 15

Define skin-load-dominated building.

Answer 15

A building whose thermal properties are more influenced by it’s skin, and therefore what’s happening outside.

Question 16

Define internal-load-dominated building.

Answer 16

A building whose exterior surface area is minimal compared to its volume. Thermal properties are more influenced by internal mass and actions.

Question 17

Define solar heat gain coefficient.

Answer 17

A measure of how much solar radiation enters a building through the windows and contributes to heat gain.

Question 18

SHGC values range between 0 and 1. What does a higher SHGC value mean?

Answer 18

The higher the value, the more solar heat is able to pass through a window.

Question 19

Which pipe type is thickest, and best for protection?
K / L / M /DWV

Answer 19

Type K

Question 20

What are thin type M pipes typically used for?

Answer 20

Typically used in low pressure scenarios. Like to remove condensation away from evaporator coils.

Question 21

What type of pipes are most commonly used for supply lines?

Answer 21

Type L

Question 22

What are DWV pipes used for?

Answer 22

Drains and vents under low pressure.

Question 23

What is grey water?

Answer 23

Water that does not involve any human food or waste.

Question 24

What are the hot water heating temperatures for kitchen/laundry, showering, and hand washing?

Answer 24

140 Kitchen/Laundry
110 Shower
105 Hand Washing