Heating: Combination of infrared heating and heat pump

The combination of infrared heating and a heat pump is possible and can be advantageous in some cases. Here is some important information about it:

How infrared heating works

Infrared heaters work by emitting infrared radiation that directly heats objects and people. Unlike traditional heaters that heat the air, an infrared heater heats the surfaces in the room, which then release heat into the surrounding air.

How the heat pump works

A heat pump uses energy from the environment (such as air, water or earth) and converts it into heat to heat a building. It works on the principle of heat exchange and can also be used for cooling.

Advantages of the combination

Combining an infrared heater with a heat pump can offer various advantages. Since infrared heaters emit direct heat, they can quickly provide comfortable warmth. The heat pump, on the other hand, works efficiently and uses renewable energy sources to generate heat. Together they can provide an energy efficient and comfortable heating solution.

Using the heat pump as the primary heating source

In most cases, the heat pump is used as the primary heating source because it is energy efficient. The infrared heater can then be used as a supplementary heating source to provide additional heat more quickly and in a targeted manner, especially in rooms that are used less frequently.

Control and regulation

Careful control and regulation is important to effectively combine the two systems. There are intelligent control systems that can control both the heat pump and the infrared heater to achieve an optimal room temperature and save energy.

However, it is important to note that the combination of infrared heating and heat pump depends on various factors, such as the building insulation, the size of the room and individual heating needs. Professional advice from professionals is advisable to find the best solution for your specific situation.

The study “Assessing the potential of infrared heating to cover peak loads” from the Technical University of Dresden confirms infrared heating as a solution to reduce the consumption of fossil energy in existing residential buildings in the short term and at the same time make the building heat pump-ready ++ Presentation of the results at the conference “Infrared heating in residential construction “

Anyone who cannot quickly switch to a heat pump in an existing home - be it due to delivery difficulties, high investment costs or a lack of time on the part of the installer - can use an infrared heater as a first step to save fossil fuels in the short term. At a later date, the homeowner can have a heat pump with a lower output installed instead of the old water-conducting heater and operate it together with the infrared heating system. With this approach, which according to the study by the Technical University of Dresden is technically feasible, the homeowner first reduces the system temperature (flow temperature) of the existing gas heating system and thus only covers the base load in the house. Higher heating requirements – the so-called peak loads – can be covered with quickly reacting infrared heaters. This reduces the consumption of fossil fuels while the house remains comfortable without the need for expensive and complex renovation measures such as new radiators, windows or insulation of the external walls.

This approach and the resulting energy requirement were examined in the study “Evaluation of the potential of infrared heating to cover peak loads” at the Technical University of Dresden using the example of a representative single-family home. The results were presented by Prof. Dr.-Ing. habil. Joachim Seifert, head of the building energy technology department at the Institute for Energy Technology at the TU Dresden, presented it for the first time at the conference “Infrared heating in residential construction” on May 11, 2023 in Würzburg. “Heat pump systems in combination with electric infrared heaters represent a technological option for old buildings. The fulfillment of the heating task and thermal comfort can be guaranteed with this system combination,” is the scientist’s conclusion.

Combination of infrared heating and heat pump

In the study commissioned by the industry association IG infrared, the scientists from TU Dresden examined whether an existing water-conducting heating system with high flow temperatures can be upgraded to operate with a heat pump at low temperatures by combining it with an infrared heater.

In order to represent the existing building stock in Germany, the team chose a single-family house with 160 square meters of heated usable space and a thermal insulation standard in accordance with Thermal Insulation Ordinance 95.

The standard heating load is 9.2 kilowatts, the specific heating load is 57.20 watts per square meter. The simulation was carried out using the coupled building and system simulation TRNSYS-TUD.

In the simulation, the existing building has a low-temperature gas boiler. The heat is transferred via radiators. Based on this, the scientists reduced the flow temperature in order to demonstrate the potential of infrared heating with basic temperature control using the existing gas heating or radiators.

Combination of unregulated basic heating and regulated infrared heating

The analysis was carried out in a sequence that can be carried out in practice by homeowners. First, the building's basic temperature is controlled using gas heating. Starting from the heating system with a flow temperature of 70°C and a return temperature of 55°C (ϑV/ϑR = 70°C/55°C), the maximum temperature of the heating curve was reduced to a flow temperature (ϑV) of 40°C and a heating curve of ϑV/ϑR = 40/30 set. In seven out of ten rooms, the now unregulated radiators will now be supported by infrared heaters.

In the next step, the low-temperature boiler was replaced with an air-water heat pump. The scientists made no changes to the dimensions of the heat transfer system, i.e. the radiators, or to the insulation standard. On this basis, the variants were then compared and the final energy required was determined. The prerequisite at all times was that criteria for thermal comfort were adhered to during times of use. With the selected parameters, the infrared heating covers the useful energy expenditure proportionately in a range of 26 to 38 percent.

Performance deficits can be compensated for by infrared heating

“The results show that the resulting performance deficit can be compensated for by infrared heating,” write the scientists at TU Dresden in the conclusion of the study and continue: “Overall, the study shows that by supplementing a water-based heating system with an infrared heater, an existing, for A heating system designed for higher temperatures can be used with low system temperatures without replacing the heating surfaces and is therefore well suited for combination with a heat pump. The analyzes have shown that compared to the basic variant, the final energy can be reduced by up to 62% through this combined use.” Peak loads can be covered with different systems at a reduced base temperature. “However, infrared heating is particularly suitable for this purpose due to its short response times.”

Use savings for photovoltaic systems

Since infrared heaters are inexpensive, available and installed in just a few hours, this approach can be implemented by homeowners at short notice and with low investment costs,” says Lars-Henric Voß, 1st Chairman of IG Infrared Germany.

The study shows that a so-called deep renovation of the building envelope and changes to the water-conducting heat transfer system can be dispensed with. This leads to significantly lower investment costs and thus to a lower financial burden on homeowners and also to economic relief, as no subsidies are necessary. “The money saved in this way can be used sensibly for a larger photovoltaic system to generate even more climate-friendly solar power - and not just for room heating, but also for user electricity, warm water and e-mobility,” adds Dirk Bornhorst, board member of IG Infrared.

Source: Press release 'Infrared heating accelerates switch to heat pump'

A combination of unregulated basic heating and regulated infrared heating is generally possible. Here is some information about it:

Unregulated basic heating

Unregulated basic heating usually refers to traditional central heating, where heat is provided by radiators or underfloor heating. This type of heating is often controlled by a thermostat, which measures the temperature in the room and switches the heating on or off accordingly.

Regulated infrared heating

In contrast to unregulated basic heating, infrared heating can usually be controlled individually and precisely. Modern infrared heaters have integrated thermostats and programmable controls that can be used to precisely set the temperature in the room and the heating times.

Combination of heating systems

The combination of unregulated basic heating with regulated infrared heating can make sense in certain situations. For example, basic heating could serve as a primary heating source that brings the room to a certain minimum temperature. The infrared heater could then be used as an additional heating source to provide additional comfort and targeted warmth to specific areas of the room.

Advantages of the combination

By combining basic heating and infrared heating, you can use the advantages of both systems. Basic heating ensures even and general heating of the room, while infrared heating offers a quick response time and targeted heating. This can be particularly beneficial in rooms that are only used intermittently or where individual heat preferences exist.

Control and regulation

It is important to have appropriate control and regulation to effectively combine the two heating systems. Ideally, the infrared heater should have a separate control that can be adjusted independently of the basic heating. This allows you to adapt the heat output of the infrared heater to your individual needs and save energy.

Please note that professional advice from professionals is recommended in relation to the specific requirements of your building and heating system. They can help you find the best combination and control options for your individual situation.