Assembly technology of a water-to-water heat pump with heat extraction from a borehole

Are you trying to save the environment and improve the heating system in your house? If so, take into account the cutting-edge technology of a heat pump that transfers water to water using a borehole to extract heat. This system effectively heats the water in your house while providing comfort and sustainability by taking advantage of the earth’s stable temperature below the surface.

Fossil fuels are frequently used in traditional heating systems, which increases carbon emissions and degrades the environment. A water-to-water heat pump, on the other hand, greatly lowers your carbon footprint by utilizing renewable energy that is extracted from the earth. Through the utilization of the earth’s inherent heat, this system offers a sustainable approach to home heating.

The borehole, which acts as the source of heat exchange with the earth, is one of the essential parts of this heating system. A borehole is a hole that is drilled several hundred feet or deeper into the earth in order to reach stable temperatures that are found below the surface. The borehole facilitates effective heat transfer between the ground and the heat pump via a network of pipes and a heat exchanger.

Careful design and installation are required for the assembly technology of a water-to-water heat pump that extracts heat from a borehole. Experts will evaluate your property to find the best spot to drill the borehole and put in the required fixtures. The system is set up to optimize performance and energy efficiency through precise engineering and expertise.

Purchasing a water-to-water heat pump that extracts heat from a borehole has long-term financial advantages in addition to environmental advantages. Reduced reliance on conventional heating fuels can result in cheaper energy costs and a more environmentally friendly way of life. As a result of technological advancements and growing environmental consciousness, more homeowners are utilizing creative solutions like this one to heat their homes sustainably and effectively.

Understanding the assembly technology of a water-to-water heat pump that extracts heat from a borehole is essential in the field of insulation and heating. With the help of this cutting-edge technology, which draws heat from a borehole to harness the Earth’s inherent warmth, homes can be efficiently and sustainably heated. This heat pump technology provides homeowners with a dependable means of heating their homes at a lower cost of energy and with less negative impact on the environment by taking advantage of the constant temperature beneath the earth. To guarantee the system’s longevity and optimum performance, meticulous planning and installation are required during the assembly process. By implementing energy-efficient solutions, homeowners can contribute to a greener future while maintaining comfortable indoor temperatures throughout the year.

How such a heat pump is organized and works?

In general, a heat pump functions similarly to a refrigerator—just the opposite. To reduce the temperature inside the chamber, the refrigerator extracts a portion of the exterior heat. As a result, the refrigerator’s back wall becomes noticeably hotter. By heating the coolant that runs through the home’s heating system, the heat pump "cools" the surrounding air.

Groundwater heat pumps are typically made up of the following array of components:

• external circuit;
• of the internal circuit;
• evaporator;
• condenser;
• compressor.

A pipe that circulates groundwater serves as the external circuit. It comes from a well, enters the system through the outdoor loop, contributes low potential heat energy to the system, and then empties into another well. There is occasionally a unique liquid known as "brine" submerged in water inside the outdoor loop. Additionally, this is a very effective method of absorbing heat from the surroundings.

Note: An open body of water close to the house can serve as a source of heat as well. Boreholes do not need to be drilled for the intake and discharge of groundwater.

The evaporator receives heat from the groundwater. Additionally, this is where the capillary opening allows the pressurized refrigerant to enter. Heat is transferred from the evaporator’s inner walls to the refrigerant as a result of the pressure drop, which starts the evaporation process. After entering the compressor and being compressed, the gaseous refrigerant is routed to the condenser.

Here, the refrigerant is once more transformed into a liquid state, and the energy that results is used to heat the coolant that travels through the home’s heating system’s pipes. This process transforms the water’s low potential heat energy into high potential energy, enabling the house to be heated fairly effectively—even during deep freezes. The heat pump water-water diagram makes this process very evident.

The process of converting low-potential heat energy from the environment into high-potential energy for heating the home and heating water is depicted in the water-to-water heat pump diagram.

The variations in water temperature have a major impact on the heat pump’s quality. The heating efficiency increases with temperature stability. Because the water in a borehole varies year-round between 7 and 12 degrees, the apparatus is highly effective. Use a thermostat to automate the device’s operation. It regulates the compressor’s on and off times to keep the interior temperature of the building at a set level.

How to make such a device yourself?

A "water-to-water" type DIY heat pump is composed of pre-assembled parts that must be connected in the right order. It may seem easy, but improper calculations can ruin the entire thing in real life. To determine the ideal compressor capacity, heat exchanger pipe diameter, and other system parameters, they are required. There are multiple ways for the layperson to tackle this problem:

• Use special software (for example, programs CoolPack 1.46 and Copeland);
• use online calculators that are available on the websites of manufacturers of such equipment;
• Invite a specialist who will help to calculate everything for a fee or out of the goodness of his heart.

I will now go into detail about each detail.

Detail #1 – compressor

Removing a suitable compressor from an air conditioner—like an LG split system—is the simplest method to obtain one. The heat generation and cooling outputs of a seven-watt compressor are 9.7kW and 7.5kW, respectively. One more benefit of these compressors is their low noise level when in use.

An old air conditioner’s water-to-water heat pump compressor can be taken out. Selecting a model that fits your needs both in terms of capacity and quiet operation is ideal.

Freon R22, which has a condensing temperature of +55 and a boiling point of -10, is used in many compressors. In 2030, the use of this refrigerant will be prohibited. A "younger" Freon R422 can be a good substitute. That being said, the refrigerant can be changed whenever it’s appropriate, not just when building a heat pump.

Part #2 – condenser

The condenser can be housed in a 120-liter stainless steel tank. It is split in half, a copper coil is positioned inside, two-inch thread connections are welded, and finally the tank’s two halves are joined together via welding. The following formula is used to determine the area of the coil that the refrigerant will circulate through:

• PZ – area of the coil;
• MT – Heat output of the system, kW;
• 0.8 is the heat transfer coefficient for the interaction of water and copper;
• PT – difference in water temperature at the inlet and outlet of the system, degrees Celsius.

A half-inch copper pipe, clean sanitary pipe, or special refrigeration pipe can be used to create a coil. 1-1.2 mm is the recommended pipe wall thickness. Simply wind a pipe the necessary length around any suitable cylinder, such as a gas cylinder, to form a coil. With the use of sanitary adapters, the coil’s ends are led outside. Use a clamping nut and linen to make sure the connection is tight.

Carefully wind copper tubing around a cylinder to create a coil for a water-to-water heat pump condenser. A metal rail can assist in adjusting the coil pitch.

It should be noted that, in order to avoid bubble formation, the freon pipeline’s inlet should be situated in the upper section of the condenser.

Part #3 – evaporator

An evaporator made of plastic that holds 127 liters is a suitable vessel. A wide neck makes it more convenient. The evaporator should be calculated similarly to the condenser. Without using any insulation, copper pipe can be twisted using copper wire.

An easily constructed evaporator for a water-to-water heat pump can be fashioned from a wide-necked plastic barrel. Although a barrel with a capacity of more than 120 liters is more practical to work with, the coil can also be placed in a smaller container.

Experts advise utilizing "flooded" evaporators for DIY heat pumps, where the liquefied refrigerant enters the water from the bottom and evaporates in the upper section. The necks of regular plastic bottles, sealed with sealant and linen, can be used to make adapters. Both the supply and discharge of water can be handled by standard sewer pipes. Because the thermostatic control valve element shouldn’t be heated above 100 degrees Celsius during installation, you should wrap it with a damp cloth before soldering the pipe alignment line.

Assembly and filling with Freon

You’ll need a welding machine to put the assembled devices into a single system. It is advised to install a filling valve at the compressor’s entrance; this will come in handy later. Next, you should check for vacuum in the system using a specialized vacuum pump.

You will require a cylinder with at least 2 kg of refrigerant in order to charge the system with Freon. It is advised to wait a few days after charging before monitoring the system pressure. It indicates that there are no leaks if it stays constant. Using soapy foam is the easiest way to find leaks if the pressure drops. It is best for inexperienced craftsmen to get in touch with a master who can refuel the machinery in a reliable and professional manner.

It is advised to use a single-phase starting relay for 40A, 16A fuse, electric panel, and DIN rail for automatic system regulation. Two capillary temperature sensors are required: one at the evaporator outlet (where a cut-off temperature of 0 degrees Celsius prevents the system from freezing) and one at the system outlet (where a maximum temperature of 40 degrees Celsius is recommended). It is important to keep in mind that a power outage may cause changes to be made to a controller’s settings if it is utilized to record the temperatures from both sensors.

This is the general appearance of one of the DIY water-to-water heat pump variations. The gadget is protected from above by a metal casing, which houses the control panel.

Two distinct wells should be built for groundwater intake and discharge, and an outdoor loop should be connected to the system once it is complete and its parts are positioned for convenience. In regions where well drilling is linked to specific issues, it is imperative to address this matter beforehand. In the event that drilling boreholes is not feasible, you might need to select a different type of heat pump, such as a "ground-to-water" model.

The functioning of a homemade heat pump’s pump is seen in the following video:

A water-to-water heat pump installation that extracts heat from a borehole requires meticulous planning and accurate execution. Using the natural thermal energy that is stored beneath the surface of the Earth, this technology provides a cost-effective and environmentally friendly way to heat homes. In order to guarantee the system’s longevity and best performance, proper assembly is essential.

Drilling the borehole to access the geothermal energy reservoir is one of the most important steps in the assembly process. To properly reach the right depth and extract heat, this calls for specific tools and knowledge. The heat pump unit can be installed and connected to the subterranean loop system once the borehole has been dug.

Paying close attention to details is crucial when installing the heat pump unit itself. To preserve stability and guard against damage, proper placement and a strong anchor are essential. Tightly sealing the connections between the different parts is also necessary to guarantee effective heat transfer and avoid leaks.

To ensure the heat pump is functional and efficient, extensive testing and calibration are done once it has been assembled and connected. This could entail tweaking the system to reach peak performance by modifying settings. To maintain the system’s maximum efficiency over time, routine monitoring and maintenance are also advised.

In conclusion, a dependable and sustainable method of heating homes is provided by the assembly technology of a water-to-water heat pump that extracts heat from a borehole. Through the utilization of Earth’s inherent thermal energy, this technology lessens dependency on fossil fuels and aids in reducing environmental impact. For many years to come, homeowners can benefit from efficient heating and reduced energy expenses with careful planning, exact execution, and continuous maintenance.

Video on the topic

About heat extraction from well water

Components and assembly of a water-to-water (brine-to-water) heat pump

Building from scratch water-to-water heat pump 11kW

Heat pump "water-to-water" on an Abyssinian well. Overview of components for assembly.