8. what is a water to water heat pump? course hero

Water-to-water heat pumps transfer the underground heat energy from hot water or steam to indoor hot water or steam. This hot water or steam is then distributed within homes and businesses through radiators, hot water baseboard heaters, or radiant floor heating.

Full Answer

How much water does a heat pump need to run?

First, there must be a source of water near the building that can supply the heat pump while it's running. Most heat pumps require two to three gallons per minute of source water flow per ton (12,000 Btu/hr.) of heating capacity.

Why choose water source heat pumps?

Each unit is individually packaged and relieves the stress of having the building rely on one HVAC unit to control the entire building. Water Source Heat Pumps can be easily zoned and conveniently installed either above a ceiling or in a closest.

What is the COP of a water to water heat pump?

Water-to-water heat pumps connected to geothermal sources and low temperature (95¯-120¯F) loads typically have COPs in the range of 2.5 to 3.2. Technology improvements continue to produce incremental gains in COP.

How does a water-to-water heat pump work?

By using water-to-refrigerant heat exchangers (instead of air-to-refrigerant heat exchangers), it's possible to build a water-to-water heat pump. Such a device can extract heat from a flowing source of low temperature water and deliver that heat to another, higher temperature water stream.

What is a water to water heat pump?

Water-to-water heat pumps transfer the underground heat energy from hot water or steam to indoor hot water or steam. This hot water or steam is then distributed within homes and businesses through radiators, hot water baseboard heaters, or radiant floor heating.

How does a heat pump heat water?

To move the heat, heat pumps work like a refrigerator in reverse. While a refrigerator pulls heat from inside a box and sends it into the surrounding room, a stand-alone air-source heat pump water heater pulls heat from the surrounding air and transfers it -- at a higher temperature -- to heat water in a storage tank.

What is brine to water heat pump?

In a brine to water heat pump, the heat is collected from the ground or surface water by circulating a solution of water and anti-freeze (known as 'brine') through a buried or submerged, closed-loop, ground heat exchanger.

Why are the insulated water tanks for heat pump systems referred to as buffer tanks?

Buffer Tank: A buffer tank is designed to help reduce cycling of a heat pump. It holds a circuit of heated water but it is 'black water' which runs through your heating systems such as radiators and underfloor heating.

How do heat pump water heaters work quizlet?

How does a heat pump work? Most heat pumps make use of the mechanical vapour compression cycle commonly known as the refrigeration cycle to convert heat form one temperature to another. The heat pump refrigeration cycle works on a similar principle to a domestic refrigerator but in reverse.

How does air to water heat pump work?

An air to water heat pump has an outside heat exchanger unit that is like a car radiator but instead of expelling heat to the air it takes heat from the air. The air is pulled through the heat exchanger by a fan whenever the heat pump is on.

What is in brine?

Brine Ideas There are only two ingredients in a traditional brine: water and salt. You can choose any type of salt you like, but keep in mind that different salts take up different volumes. Table salt is finer than coarse kosher salt, causing 1/2 cup of table salt to taste saltier.

How do ground source heat pumps work?

Ground source heat pumps work by absorbing natural heat from the ground and transferring the heat into buildings to provide heating and hot water in a low-carbon, energy efficient way. Ground source heat pumps (GSHPs) are units which are installed inside a building, they are powered by electricity.

Does a heat pump produce water?

Heat pumps often feature a condensate pan to catch normal condensation as it forms in the unit. That condensation then drips out of the system via a drain line. If the line becomes clogged or the pan is misaligned, water may drip out.

Do you need a water tank with a heat pump?

While you can install a heat pump without a hot water cylinder, it will only provide your heating and you would need to install another technology, or system to provide hot water. In most cases, people choose a hot water cylinder.

Why is a water source heat pump more efficient than an air to air heat pump?

A lack of humidity translates to a lack of efficient heating. When you use a water source, the temperature is more consistent. Bodies of water experience temperature change less rapidly than air.

Why are heat pumps important?

The ability to function as both a heating and cooling system is the biggest attraction of heat pump systems, especially in mid- to lower latitudes. Heat pumps are used to move heat from one medium where it's readily available to another medium that can accept it.

How hot is ground water?

The temperature of ground water ranges from about 35¯ to 60¯F, depending on its source, geographic location and time of year. As the water flows through the heat pump its temperature drops 5¯ to 15¯F as heat is extracted. The water then returns to its source where it can absorb more heat.

Why do air to air heat pumps need a defrost cycle?

Air-to-air heat pumps also require a defrost cycle to remove frost from the outdoor heat exchanger during cold weather. Hot refrigerant gas is periodically recirculated in the outdoor coil to melt the frost. The energy used to defrost also lowers overall system efficiency.

Why is geothermal heat pump called open loop?

Because the water is not contained in a pressurized closed-loop, this approach is known as an "open-loop" geothermal heat pump system. Two factors are critically important to the success of any open-loop system. First, there must be a source of water near the building that can supply the heat pump while it's running.

How hot can a water tank be?

However, the operating temperature range of such a tank is limited by the fact that most water-to-water heat pumps using R-22 refrigerant can't heat water above 130¯F without tripping their high-pressure safety switches. Even if the heated water was usable down to, say, 95¯F (i.e. in a slab-type floor heating system), the working range of the tank is a mere 35¯F. Storing large quantities of heat using such a narrow temperature range necessitates large volumes of water, the economics of which are often unfavorable.

How to extract heat from the earth?

Another method of extracting heat from the earth is to circulate water or a mixture of water and antifreeze through a closed piping loop buried several feet below grade. Heat is extracted by chilling the water circulating through the buried loop to a temperature lower than that of the surrounding soil.

Where does a space heat pump get its heat?

For space heating applications, water source heat pumps typically gather heat from the earth. Since soil temperature a few feet below the surface are considerably higher than the outside temperature during most of the winter, these "geothermal" systems enjoy a major performance advantage over their air-source counterparts.

How does a water source heat pump work in different seasons?

Heat is delivered to each unit from the water of the loop in extremely cold weather. When more heat is required, then it is generated internally in the building. In such circumstances, these units switch to the heating mode.

What is a water source heat pump?

Water source heat pumps are efficient units that extract heat from water rather than air. They offer competent performance for residential and commercial needs.

What is a heat exchanger?

Also, a heat exchanger replaces the external fan and coil in a water source heat pump. The building must offer a water loop for this system to function. A cooling tower and a boiler are included in this water loop. It is to keep the water entering and leaving the unit at ideal levels. The water source heat pump working principle is mainly affected by these loops.

What happens to the refrigerant in a water heat pump?

The refrigerant leaves the 4-way mixing valve and travels to the refrigerant-water heat exchanger. This happens during a cooling cycle. The fan and coil on the outer unit of the residential unit of the water source heat pump design help to reject heat to the outside air.

What happens to the liquid in a heat exchanger during the cooling cycle?

The high-pressure low-temperature refrigerant liquid leaves the heat exchanger. Then it flows toward the thermal expansion device during the cooling cycle .

How long do heat pumps last?

Depending on how often they are used, heat pumps can last anywhere from 11 to 21 years. Though 15 is the average. Heat pumps are comparable to air conditioners in terms of functionality. But because they can provide both heating and cooling, they are often utilized for a longer period of time. You can get maintenance help from nearby water source heat pump manufacturers and service providers for elongated unit durability.

How is heat absorbed in a water loop?

Heat is absorbed from the zones in the building and rejected into the water loop during hot weather when most or all of the units are running in cooling mode. Heat is also expelled from the building through an external fluid cooler attached to the loop if it is not required elsewhere in the building.

What is a water source heat pump?

One of the most efficient and reliable HVAC systems for your building is a Water Source Heat Pump (WSHP). Simple in design, a WSHP rejects heat in the cooling cycle through a Cooling Tower loop. The water loop is piped through a building and each Heat Pump is connected individually.

How long does a water source heat pump last?

The effortless design also allows for a longer shelf life for this style of system. WSHP’s tend to operate efficiently for 15 to 20 years without major complications. When the time comes to replace the unit, then there are many manufacturers that have designed their new Water Source Heat Pumps to be easily retrofitted to match your existing equipment.