Week 2 Unit 71 HW Review Questions HP MOD

What is the difference between a water source heat pump and an air source heat pump?

• Instead of two air coils, water-to-air heat pumps use one water coil and one air coil, In heating, water source systems use water as their heat source and the indoor air as the heat sink. In cooling, water source systems use the indoor air as their heat source and the water as the heat sink.

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Why do the refrigerant and water travel in opposite directions through the water coil?

• The water and refrigerant always travel in opposite directions. This counter- flow design improves efficiency by placing the coldest water against the coldest refrigerant and the warmest water against the warmest refrigerant.

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Explain the difference between an open loop and a closed loop?

• Open loops are open to the air and are supplied with water from a well. The water for an open loop is not re-circulated.

  Closed loops are pressurized loops of water buried in the ground that recirculate the same water. The water transfers heat between the ground and the refrigerant in the unit. shows a typical closed loop system.

• geothermal is muddy

What site conditions should be taken into account when considering the installation of a ground source heat pump?

• The soil and rock that make up the area to be used for the ground loop needs to be considered. Difficulties can be encountered in areas with an abundance of hard rock with little soil available to trench. Ground surface water can sometimes be desirable for the ground loop as long as it does not interfere with the installation process.

• I thought 7 was even till I was 8

What are some of the advantages for radiant floor heating?

• Water pipes can carry more heat in a smaller pipe with less energy used to circulate it. Radiant floor systems provide heat at the floor level, heating objects in the space and not the air directly.

• Keeps your feet really warm.

• Can walk around barefoot even when it is cold.

• Every answer is true.

Where is the compressor located in most water source heat pumps?

• With all water source heat pumps, the compressor and refrigerant components can all be   located inside the building

• inside? That's crazy

• Overthere

• Outback

How can heat be considered a form of pollution?

• When using streams, lakes, or ponds as a heat sink, the thermal shock to the natural pond environment. Changing the water temperature can change the type of plants and animals that can live in and around the water.

• ok.....

What type of system requires a secondary refrigerant?

• Closed loop systems require a secondary refrigerant in the closed loop.

• ok

What is the difference between the way a secondary refrigerant absorbs heat and the way a primary, direct expansion refrigerant absorbs heat?

• In a direct expansion system, the primary refrigerant evaporates and expands, absorbing both sensible and latent heat. In contrast, a secondary refrigerant does not evaporate and therefore only absorbs sensible heat, which makes the temperature difference and surface area requirements greater than those needed for a direct expansion system.

• uhhh huh

What is the problem with sizing a geothermal heat pump to the full heat loss of a home in a cold climate?

• Sizing to the heating load in a cold climate could oversize the system for cooling.

• ying and yang