How
a heat pump works

ALTAL heat pumps, DC inverter, EVI function

What is a heat pump and how does it work?

A note on home energy management

Heat pumps are very efficient heating and cooling systems and can significantly reduce your energy costs. Thinking of the house as a system, it is recommended that the heat loss in your home be minimized in areas such as air leaks (through cracks, holes), walls, ceilings, windows and poorly insulated doors.
Addressing these issues first can allow you to use a smaller heat pump, reducing the cost of heat pump equipment and allowing your system to run more efficiently.
A number of publications explaining how to do this are available on the ALTAl website or on the global Internet.

Basic concepts

Heat pumps are a proven technology that has been used globally for decades to provide efficient heating, cooling and, in some cases, domestic hot water. In fact, it is possible to interact daily with heat pump technology: refrigerators and air conditioners work using the same principles and technology. This section introduces the basics of how a heat pump works and different types of systems.

Why a heat pump?

Heat pump as a modern system

If you are exploring options for heating and cooling your home or reducing your energy bills, you may want to consider a heat pump system. Heat pumps are a proven and reliable technology globally, able to provide year-round comfort control for your home by providing heat in winter, cooling in summer and, in some cases, heating hot water for your home.

Heat pumps can be an excellent choice in a variety of applications, both for new homes and for upgrading existing heating and cooling systems. They are also an option when replacing existing air conditioning systems, as the incremental cost of switching from a cooling-only system to a heat pump is often quite low. Given the multitude of different types and options of systems, it can often be difficult to determine if a heat pump is the right choice for your home.

Advantages of heat pumps

Efficiency

Compared to other heating and cooling systems, heat pumps are more efficient. They use less energy and fuel to heat / cool your home, and some water pumps have efficiency rates of up to 600%. They also have a long lifespan of up to 50 years.

Three functions

An advantage of investing in a heat pump is that it is designed to distribute heat and cooling, as well as domestic hot water in homes. This can help you save some money by reducing the costs associated with installing two different systems. In addition, it takes up less space because it is a single system with three functions.

Reduces emissions

One of the major advantages of a heat pump is that it is environmentally friendly. Because no fossil fuels are used to operate the heat pump, there is no harmful fumes that are released into the air. Reducing carbon emissions helps the environment. This also helps home users to save money annually.

Minimum maintenance

Heat pumps do not require much maintenance. The low maintenance required for a heat pump is an advantage for homeowners looking for ways to save money on expensive home repair projects.
This helps to save money in the long run.

Air-to-water heat pumps ALTAL

Heat pumps with air source

Air source heat pumps use outside air as a source of heat in heating mode and as a sink to dissipate energy in cooling mode. These types of systems can generally be classified into two categories:
Mini-Split: A single indoor unit is located inside the house, served by a single outdoor unit. In the outdoor unit there is the compressor, the air heat exchanger, the rest of the components. Only the water heat exchanger and the circulation pump are installed in the indoor unit. This type of heat can work up to ambient temperatures of -15 ° ...- 20 ° if DC Inverter and EVI (steam injection) technology is used.

Mini-Split: A single indoor unit is located inside the house, served by a single outdoor unit. In the outdoor unit there is the compressor, the air heat exchanger, the rest of the components. Only the water heat exchanger and the circulation pump are installed in the indoor unit. This type of heat can operate up to ambient temperatures of -15C ° ...- 20C ° if DC Inverter and EVI (steam injection) technology is used. Mini-split air-to-water heat pumps use water as a heating medium for heating, cooling and domestic hot water preparation.
Full-Split: A single indoor unit is located inside the house, served by a single outdoor unit. Only the heat exchanger and the fan are in the outdoor unit. The compressor, the air heat exchanger, the rest of the components are installed in the indoor unit. This type of heat can work up to ambient temperatures of - 25C ° if DC Inverter and EVI (steam injection) technology is used. Mini-split air-to-water heat pumps use water as a heating medium for heating, cooling and domestic hot water preparation. Of the series of air-to-water heat pumps, they are the most efficient, they have a high economic / power efficiency.
Multi-Split: multiple indoor units are located in the house and are serviced by a single outdoor unit. In the outdoor unit there is the compressor, the air heat exchanger, the rest of the components. Only convection valves with a freon heating agent are installed in the indoor unit. These air-to-water heat pumps use only convection heating / cooling. It has the lowest economic / power efficiency. They can operate up to ambient temperatures of - 20C ° max.

Single-speed, variable-speed heat pumps

Of particular importance when considering efficiency is the role of new compressor models in improving seasonal performance.

Typically, units operating at the prescribed minimum SEER and HSPF are characterized by single-speed heat pumps. Variable speed air source heat pumps are now available that are designed to vary the capacity of the system to better suit the heating / cooling demand of the home at a given time. This helps to maintain maximum efficiency at all times, including in milder conditions, when there is a lower demand for the system.
More recently, heat pumps with air source have been introduced on the market, which are better suited to operate in the cold climate of Europe and the CIS thanks to EVI (steam injection) technology. These systems, often called cold climate heat pumps, combine design variable capacity compressors and improved heat exchanger controls to maximize heating capacity at lower air temperatures while maintaining high efficiencies in milder conditions. These types of systems typically have higher SEER and HSPF efficiency values, with some systems reaching SEER up to 42 and HSPF approaching 13.

Major benefits of air source heat pumps
Installing an air source heat pump can provide a number of benefits. This section explores how air source heat pumps can benefit your home's energy footprint.
•Efficiency
The major benefit of using an air source heat pump is the high efficiency it can offer in heating compared to typical systems such as gas boilers, wood and pellet boilers, electric boilers. At 7 ° C, the coefficient of performance (COP) of heat pumps with air source usually varies between 2.0 and 5.4. This means that for units with a COP of 5, 5 kilowatt-hours (kWh) of heat is transferred for every kWh of electricity supplied to the heat pump. As the outside air temperature drops, the COPs are lower, as the heat pump must operate at a higher temperature difference between the indoor and outdoor space. At -8 ° C, COPs can range from 1.1 to 3.7.
On a seasonal basis, the seasonal heating performance factor (HSPF) of units available on the market can range from 7.1 to 13.2. The actual savings largely depend on the location of the heat pump installation. • Energy savings
The higher efficiency of the heat pump can be explained by significant reductions in energy consumption. The actual savings in your home will depend on a number of factors, including local climate, current system efficiency, heat pump size and type, and control strategy. Many online computers are available to provide a quick estimate of how much energy you can expect for your application.

Ground-to-water heat pumps ALTAL

Ground source heat pumps

Terrestrial heat pumps use earth or groundwater as a source of thermal energy in heating and cooling mode. Groundwater heat pumps are the most efficient. These types of systems contain two key components:
• Ground heat exchanger:
This is the heat exchanger (geothermal wells in wells, or groundwater, lakes) used to transform or remove energy. thermal earth or earth. Different heat exchanger configurations are possible.
• Heat pump:
Instead of air, ground-to-water heat pumps use a fluid that flows through the ground heat exchanger as a source (in heating) or sink (in cooling).
On the building side, both air and hydronic (water) systems are possible. Operating temperatures on the building side are very important in hydronic applications. Heat pumps work more efficiently when heated to lower temperatures below 35 to 50 ° C, making them a better fit for warmer floors (warm floors) which are the most efficient or fan coil systems, which are more efficient. inefficient. Care should be taken when considering their use with high temperature radiators that require water temperatures above 60 ° C, as these temperatures generally exceed the limits of most residential heat pumps.

Depending on how the heat pump and the ground heat exchanger interact, two different system classifications are possible:
• Secondary loop: A liquid (groundwater or antifreeze) is used in the ground heat exchanger. The heat transferred from the ground to the liquid is delivered to the heat pump via a heat exchanger.
• Direct expansion (DX): A refrigerant is used as a fluid in the ground heat exchanger. The heat extracted by the refrigerant from the ground is used directly by the heat pump - no additional heat exchanger is needed.
In these systems, the ground heat exchanger is a part of the heat pump itself, acting as an evaporator in heating mode and a condenser in cooling mode.

Ground heat pumps can meet a number of comfort requirements in your home, including:

Heating only: The heat pump is only used for heating. This can include both space heating and hot water production.
"Active cooling" heating: The heat pump is used for both heating and cooling.
"Passive cooling" heating: the heat pump is used for heating and stopped for cooling in the refrigeration contour. When cooled, the building fluid is cooled directly in the floor heat exchanger.

Major benefits of terrestrial heat pump systems

• Efficiency
In case the ambient air temperature can drop below -30 ° C, ground source systems are able to operate more efficiently because they take advantage of warmer and more stable ground temperatures (from + 8 ° C to + 17 ° C in our regions). Typical temperatures of water entering the ground heat pump are generally above + 5 ° C, producing a COP of about 4 for most systems during the colder winter months.
• Energy savings
Ground floor systems will substantially reduce your heating and cooling costs. Energy savings for heating compared to electric, gas and pellet ovens are about 65%.
On average, a well-designed ground source system will save about 20-30% more than a best-in-class cold air-conditioned heat pump, sized to cover most of the heating task of the building. This is because underground temperatures are higher in winter than air temperatures. As a result, a ground source heat pump can provide more heat during the winter than an air source heat pump.
Actual energy savings will vary depending on the local climate, the efficiency of the existing heating system, the costs of fuel and electricity, the size of the installed heat pump, the configuration of the drilling field and the seasonal energy balance and the performance of the heat pump efficiency. rating conditions.

How a heat pump works