Heat pumps midterm

Until temperatures reach ______________, There is still heat energy in the air.

-460F

What are 5 things that impact the cost of a geothermal system? Answer text

1. License and permits 2. Ground water level and ground moisture levels 3. System options 4. Labor costs 5. Costumer lifestyle

Vertical loops are typically drilled to a depth of __________________ft.

100

Of the energy received by the sun, What percent is absorbed directly by the atmosphere?

15%

If something is labeled 100% Efficient, then that means its Coefficient of performance (COP) is,

1:1

What is the approximate length of pipe required per ton of air conditioning?

300-500

Transfer heat from the air to the refrigerant

Air Source Heat Pumps

If the indoor air needs to be heated during the defrost cycle, then Supplementary or ___________ heat is turned on.

Auxiliary

f the indoor air needs to be heated during the defrost cycle, then Supplementary or ___________ heat is turned on.

Auxiliary

A______________ system uses the same water to exchange heat.

Closed loop

Use water-based fluids, sealed in a loop, to transfer heat energy to and from the refrigerant

Closed water Loop Heat Pumps,

The indoor coil is functioning as the _____________ in heating mode.

Condenser

When the top in a 3 way value is connected to the outdoor coil what mode is it in

Cooling mode

Use refrigerant in a coil, buried in the earth, to transfer heat energy to and from the refrigerant

Direct Expansion Heat Pumps,

As temperatures drop outside, the heat transferability from outside air to the outdoor coil _________.

Drops

Match the following Heat Pump thermostat terminals with their appropriate definition.

E/AUX auxillary heat G Fan R 24v power Y Compressor B reversing vaulve (heat) O reversing vaulve (cool) C 24v common

Superheat is the extra heat that is picked up during the ____________ phase of the refrigeration cycle.

Evaporating

A heat pump system requires more refrigerant in heating mode than in cooling mode.

False

The Refrigerant changes state once it passes through the Filter Dryer.

False

The direction of refrigerant flow through a compressor in a heat pump system changes direction when the system switches between heating and cooling modes.

False

Three types of loop systems are used for geothermal heat pump systems. They are Open loop, Closed loop, and Slinkey.

False

When the outdoor air temperature is low and Dew point temperatures are reached, _________ accumulates on the coil surface.

Frost

Transfer heat energy from either the ground or from water in the ground

Geothermal Heat Pumps,

One efficacy advantage that both ground source and water source heat pumps have that air source heat pumps does not have is____________________________________________________________________________________________.

Ground source and water source do not require a defrost cycle.

describe the relationship between ground-water temperature and ground temperature.

Ground temp, usually stays the same around 50 degrees and the water temp relatively. When you run water through the ground through pipes gets the water to the temperature of the ground

Use a buried ground loop to transfer heat energy from the ground directly to the refrigerant or use a water-based fluid in the loop to transfer heat to the refrigerant

Ground-Source Heat Pump,

Transfer heat energy from one area to another.

Heat Pumps

When the top in a 3 way value is connected to the indoor coil what mode is it in

Heating mode

What state is the Refrigerant as it leaves the compressor?

High Temperature, High Pressure Vapor

What state is refrigerant when it leaves the condenser

High temp, high pressure liquid

What state is refrigerant is in when it leaves the compressor

High temp, high pressure vapor

What state is the Refrigerant when it Enters the Condenser?

High temp, high pressure vapor

Coefficient of performance

In watt if useable heat of each watt of energy purchased Using electric resistance heat This is called 100% effluent Coefficient of performance is 1:1 Air to air heat pumps can have CoP if 3.5:1 When 1 watt of electrical energy is used by the compressor it can furnish 3.5 watts of useable heat

In heating mode what does the indoor and outdoor coil act as

Indoor: condenser. Outdoor: evaporator

I'm cooling mode what does the indoor and outdoor coil act as

Indoor: evaporator. Outdoor:condenser

The two types of single use heat pump systems are Pump to Dump and _______________________.

Injection

Freeze Point _____________________________________________________________________________________.

Is the temperature at which a substance begins to freeze

Energy from the sun is largely absorbed by ______________ and _________________.

Land and oceans

A heat pump system will capacity (Efficacy) as the outside temperature drops.

Lose

What state is the Refrigerant when it leaves the Condenser?

Low Temperature, Low Pressure Vapor

What state is the Refrigerant when it leaves the TXV?

Low temp, low pressure liquid

What state is refrigerant when it leaves the evaporator

Low temp, low pressure vapor

Electronic expansion value

Meter refrigerant, can do heating and cooling modes Works in both directions Similar to txv

In Defrost, the outdoor coils fan is___________.

Off

Capillary tubes on indoor coils

Only used in cooling mode

Use ground water only for pump and dump systems and other water based fluids, which may be exposed to the atmosphere, to transfer heat energy to and from the refrigerant.

Open Water Loop Heat Pumps

What type of tubing is recommended for use as a ground loop?

Polyethylene

Water-Source Heat pumps were popular before the production of what?

Propane

Auxiliary heat

Required when the heat pump can't provide all the heat needed The heat pump is the primary heat source Auxiliary heat could be electric oil, or gas Electric is the most common Outside temp drops the more heat is required to heat up the house

The process of cooling a liquid refrigerant below its saturation point is referred to as ________________.

Sub cooling

Air to air filter dryer

Temps as low as 10F Outside coil absorbs the heat Difference from outside to evaporator is about 25F The compressor and system looses efficiency

What is super heat?

The amount of heat in a vapor above its saturation point.

Which of the following statements about a heat pump operating in cooling mode is false?

The compressor pumps high-pressure refrigerant vapor into the indoor coil.

A "Slinky" ground loop is called a "Slinky" because it resembles a Slinky toy that has been pushed flat.

True

A heat pump is effective only when the ratio of heat pump output to heat loss is at or above the balance point.

True

A heat pump may use two metering devices in order to circulate refrigerant in either direction.

True

An air coil circulates refrigerant and absorbs heat from or releases heat to the air.

True

An air-source heat pump may emit steam in cold weather as it defrosts.

True

Another name for an open loop system is a "Pump and Dump" system.

True

Because the pipe is laid over itself in an slinky installation, this means it can be laid in a smaller area than other piping configurations.

True

Bi-flow filter driers were specifically designed for Heat pump applications.

True

Direct Expansion heat pumps do not use a loop

True

During the cooling mode in a heat pump, the reversing valve routes refrigerant from the compressor to the outdoor coil.

True

Electric crankcase heaters are used to warm a heat pump's compressor dome prior to start-up.

True

In heating mode, the outdoor coil functions as the evaporator.

True

Two standard filter driers can be used on heat pump systems as long as check valves are used.

True

If the heat pump is operating below the balance point, then it will

Turn on the Auxiliary heaters.

Liquid line accessories

Two standard filter dryers could be used on a system with check values Only one would be on the circuit at the time

Orfaced metering device

Used in conjunction through check values On device located on each coil Bore on inside coil is bigger then outside Normally used to ugh biflow filter dryers

Thermometric explanation value at outdoor coil

Used in heating mode Allows maximum efficiency quickly

Use water as a heat energy transfer medium to transfer heat to or from the refrigerant.

Water Source Heat Pumps

Explain how water is only used once in a single-use system.

Water is taken from a source of water then it leaves it in another tank or a different spot

Balance point

When the heat pump can pump exactly the amount of heat leaking out Above balance point heat pump cycles Below the heat pump runs constantly

Auxiliary heat is typically electric, but it can also be,

a. Natural Gas b. Propane c. All of the above d. Fuel Oil

Auxiliary heat for a heat pump ____.

a.is needed when it is not possible for the heat pump to extract enough heat from the outside air b.may use electric heating coils in the supply air ducts c.is not as efficient as normal system operation d.All of the above.

A heat pump that uses the outside air as a heat source or a heat sink for producing the desired temperature in a conditioned space is a(n) ____ heat pump.

air-source

Why is defrost needed on Air to Air heat pumps?

b. Shed the frost from the coil and restore efficacy.

An air-source heat pump's heating cycle ____ as the outdoor temperature drops.

becomes less efficient

A substance that is toxic and requires special handling.

enthylene glycol

When a heat pump is operating in heating mode, the outdoor coil functions as a(n) ____ by absorbing heat.

evaporator

What state is the Refrigerant when it enters the Evaporator?

low temperature, Low Pressure liquid

What state is the Refrigerant when it leaves the Evaporator?

low temperature, Low Pressure liquid

Otherwise known as "Wood Alcohol", This is more toxic than propylene Glycol.

menthanol alcohol

What is Balance point?

occurs when the heat pump can pump in exactly as much heat as the structure is leaking out

A __________ system brings in new water to the refrigerant heat exchanger and discharges the used water

open loop

A substance that is less toxic and safer to handle.

propylene glycol

Auxiliary heat .

s required when the heat pump cannot provide all the heat a structure needs

There are two types of "single use" heat pump systems.

true