Sait Racm Hvac 353 4Th (2024): Heat Pumps And Advanced Mechanical Drives

Front 1

What is the difference between BHP and HP curve

Back 1

Back (Definition)

Front 2

What is defrost mode in a heat pump for winter?

Back 2

It will run the system in cooling mode

Front 3

Will defrost make an ice pool on the outside unit after a defrost?

Back 3

Yes, you might need a riser to keep the heat pump above the snow.

Front 4

Will auxiliary heat turn on when the outdoor unit is on defrost?

Back 4

Yes, this will ensure the supply air is warm.

Front 5

What are the 2 ways to initiate a defrost?

Back 5

(1) Demand-frost method (monitors the pressures to detect frost).

(2) time-temperature defrost (monitors temperature snap disc outside every 30,60, or 90 minutes)

Front 6

Where is the indoor coil installed on a residential furnace?

Back 6

Downstream of the furnace. (Aka in the normal place).

Front 7

What is the difference between closed loop and open loop geothermal loops?

Back 7

In a closed-loop geothermal heat pump system, a continuous loop of fluid (usually a mixture of water and antifreeze) circulates through buried pipes or vertical boreholes to exchange heat with the surrounding earth. Unlike an open-loop system, a closed-loop system doesn't extract or discharge water from the ground; it operates within a sealed loop. Closed-loop systems are more common and versatile, suitable for areas with limited water availability or specific geological conditions.

Front 8

How much pipe do you need per ton of cooling for a ground source heat pump?

Back 8

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 9

How much pipe do you need per ton of cooling?

Back 9

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 10

How deep does the loop need to go in a vertical loop?

Back 10

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 11

How much pipe do you need per ton of cooling?

Back 11

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 12

How deep does the loop need to go in a vertical loop?

Back 12

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 13

What is the minimum spacing between vertical holes?

Back 13

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 14

How much pipe do you need per ton of cooling?

Back 14

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 15

How deep does the loop need to go in a vertical loop?

Back 15

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 16

What is the minimum spacing between vertical holes?

Back 16

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 17

What is the minimum grade for a horizontal loop?

Back 17

Horizontal loops must be:

• 10 ft below grade minimum (Alberta) and

• 300 ft (or longer per ton) with 6 inch spacing

Vertical loop bore holes (Alberta) must be must be:

• 200-300 Ft deep,

•250-300 Ft per ton in length,

• 3-4" in diameter,

• 20 ft spacing between holes (15 ft Min.)

Front 18

Does the heatpump hwt fully heat the water?

Back 18

No, only 25-50% of the heating bill is removed with a heat pump

Front 19

What is a CRAC unit?

Back 19

COMPUTER ROOM AIR CONDITIONER

A CRAC unit is an air conditioner for data centers, ensuring ideal conditions for electronic equipment by controlling temperature and humidity.

Front 20

Where do you install heat pumps?

Back 20

Outside of the drip line. (Away from the edge of the roof)

Front 21

Dont need data center on TQ

Back 21

Yup

Front 22

Does a crac system need under air floor?

Back 22

Yes,

Front 23

Dont need data center on TQ

Back 23

Yup

Front 24

Does a crac system need under air floor?

Back 24

Yes,

Front 25

Crac vs Crah

Back 25

CRAC VS CRAH

• The main difference between

CRAC and CRAH cooling units is that CRAC units use

refrigerants and compressors, whereas CRAH units use chilled water and control valves.

• CRAC cooling units have a simpler functionality as there is typically only one mode once turned on.

Front 26

What is liquid cooling direct to chip?

Back 26

Not on TQ

Liquid Cooling - Direct to Chip

. This developing area shows promise for modern data center cooling, since it's cleaner and more efficient than air cooling.

• Liquid cooling also means you don't have to maintain two separate systems, which boosts efficiency.

Front 27

Immersion cooling

Back 27

Immersion Liquid Cooling

• Immersion cooling, also known as "direct liquid cooling'; iS a technique used for computer cooling, battery cooling, and motor cooling in which electrical and electronic components, including complete servers and storage devices, are mostly or fully submerged in a thermally conductive but electrically insulating liquid coolant.

Front 28

What is a DATA ROOM COOLING SYSTEM?

Back 28

Data Room Cooling Equipment

. The data room cooling system is typically a split system with remote condensing units that provide precision controlled heating, cooling, humidification and dehumidification, and that is supplementary to the main building cooling system.

Front 29

What is economizer mode in Data room cooling?

Back 29

They just use a refrigerant pump and use the ambient air the reject heat.

Front 30

What grade do you need for a window shaker?

Back 30

Installation Procedures

• In addition to ensuring that the window air conditioner installation is safe and secure, you must make certain that the positioning of the unit allows for sufficient condensate drainage.

• Some types of units require a slope of ¼" grade toward the outside of the building to allow the condensate to flow and drip to the outdoors.

• If the condensate does not drain properly to the outside, it can cause damage indoors.

Front 31

How do you install a condenser in respect to the prevailing wind?

Back 31

In a ductless split you want the unit 90 degrees from the airflow.

For a refrigeration, have the prevailing wind so it works with the fan and not against it.

Front 32

Do you need to know the weight of the new unit when installing it?

Back 32

Yes,

Make sure that the surface on which the equipment is to be installed is designed to withstand the unit's weight.

Front 33

TQ: what needs to be on top of the curb before you put the unit down?

Back 33

Foam tape

Front 34

TQ?: What do you need to protect the unit?

Back 34

The unit must be lifted using spreader bars to prevent the slings from damaging the unit.

The spreader bars should be equal to the width of the unit.

Front 35

Power must be turned on for how long before start up?

Back 35

24 hrs before start-up.

(pressure of the refrigerant and temperature of the oil are important on start up.)

Front 36

What is the building envelope?

Back 36

Barrier between Conditioned vs uncondition spaces

Front 37

Dont worry about roof penetrations because its not on the test.

Back 37

Yup

Front 38

How many feet from the edge?

B-52 or B-149?

Back 38

10 ft is B-52

6ft is B-149

Front 39

Sleepers must be made of what type of material?

Back 39

Non-combustible

Front 40

Sleepers must be made of what type of material?

Back 40

Non-combustible

Front 41

Insulation on a liquid line if it passes through an ambient room warmer than the condensing temperature?

Back 41

True

If the room is warmer it will remove subcooling… not a happy txv.

Front 42

What is the maximum voltage imbalance?

Back 42

2%

Front 43

What must the supplied voltage be within?

Percentage?

Back 43

10%

Front 44

If you have 2 slab evaporators and they are stacked which one is the first stage?

Back 44

First stage is the lower one!

Front 45

How far down should horizonal loops be?

Back 45

10 ft down

Front 46

If you have 2 slab evaporators and they are stacked which one is the first stage?

Back 46

First stage is the lower one!

Front 47

How far down should horizonal loops be?

Back 47

10 ft down

Front 48

How far apart should vertical loops be?

Back 48

20 feet apart

Front 49

What is the outdoor design condition?

Back 49

The balance point where the heat pump can meet the demands of the home.

Front 50

All glycol piping underground need to be…?

Back 50

Fused joints.

Hydrostatic pressure test to 100 psi

Front 51

Where is the surge line and why do we stay away from it?

Back 51

The operating point becomes unbalanced leading to unstable operation

Front 52

What is the operating point?

TQ:What can cause fan surge?

Back 52

The point on the graph where the rpm and pressure

A large fan running too slowly. It starts hoping on the graph in the flat spot. Providing 0 CFM to whatever CFM starts dropping in relation to pressure.

Front 53

Relationship between RPM AND CFM?

Back 53

(RPM(2)/RPM(1))

=

((CFM(2)/CFM(1))

If RPM = 2

Then CFM = 2

Front 54

What is the relationship between RPM AND SP

Back 54

(RPM(2)/RPM(1))^2

=

(SP(2)/SP(1))

Front 55

Relationship rpm and hp

Back 55

(RPM(2)/RPM(1))^3

=

(hp(2)/hp(1))

Front 56

Backwards inclined is non-overloading?

Back 56

True

Forward inclined is overloading

Front 57

Flex duct is….

Back 57

Terrible

Front 58

What is direct vs indirect drive?

Back 58

Motor connected directly or with a belt.

- (1/64” per inch)

Remove plug on bottom of motor (depending on how its mounted) from motor housing

-loosen motor mount and remove tension on belt, remove belt, replace and tension belt before tightening down motor mount.

Front 59

What are the 3 fan groups?

Back 59

Fan Wheel Groups

K Wheel - Blades cannot be adjusted; Simple basic fan

A Wheel - Blades can be adjusted but only when stopped

C Wheel - Blades can be adjusted while the fan is running

Front 60

What is a cross flow fan?

Back 60

It has the air going perpendicular the the shaft.

Front 61

What is the difference between BHP and HP?

Back 61

"BHP" stands for brake horsepower, and "HP" stands for horsepower. Both terms are often used interchangeably, but technically, BHP refers to the engine's output before losses like friction and other external factors, while HP represents the power delivered to the wheels. In practical terms, the difference is often negligible for everyday discussions about a vehicle's power.

Front 62

The fan law curves are on the test and not the graphs of the curves.

Back 62

Yep

Front 63

VAV summary notes on test

Back 63

Back (Definition)

Front 64

VAV summary notes 2

Back 64

Back (Definition)

Front 65

What is the difference between cool aisle and hot air containment?

Back 65

Back (Definition)

Front 66

What is an edge data centre?

Back 66

Back (Definition)

Front 67

What is an enterprise data centre vs and edge data centre?

Back 67

Edge is multiple corporations

Front 68

What height is a heat pump set to?

Back 68

12-24 inches above the ground

Front 69

In a MUA with a heating coil what needs to happen if the freeze stat trips?

Back 69

Open zone valve, turn on pump, close dampers, turn off fan

Front 70

What causes noisy and drafty office space from the diffuser?

Back 70

High velocity/volume

Front 71

How do you test a geothermal loop?

Back 71

100 psi hydrostatic