Heat pumps use low-grade heat from the air and boost it to a higher temperature level to heat your home and provide domestic hot water. To prepare domestic hot water an air-source heat pump has to operate at high pressure, at the limit of its operating window, leading to high electricity consumption and increased wear on its components. Also, the heat pump operates all year round for domestic hot water preparation, also in spring and summer, generating noise when you want to enjoy the warm weather. Combining your heat pump with our Direct Multi-Pass (DMP) Solar System means that the heat pump does not need to prepare hot water for up to 180 days a year (including all those nice sunny days), which reduces noise pollution, decreases you electricity bill, and increases the lifetime of your heat pump.
Our DMP Solar system is tailored to be combined with air-source heat pumps, and shares the same buffer tank, so no extra buffer tank is required. We use highly efficient vacuum tube collectors, connected directly to the buffer tank, to create a robust, maintenance-free solar thermal system, ideal for combining with heat pumps. Our unique solar thermal system, using our patented Thermo-Differential Valve technology, ensures that high-grade heat is generated at the required temperature for domestic hot water production, so that free heat from the sun is immediately available, and the heat pump can stay off for longer.

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• In the morning, when solar intensity is low, the DMP solar system charges the cool bottom of the storage tank.

• When the hot tap is opened, the Hot Water Unit rapidly takes heat from the top of the buffer tank to heat the potable water using its efficient plate heat exchanger.

• Charging of the bottom zone continues while solar intensity is low.

• When solar intensity increases, the DMP (Direct Multi-Pass) Solar System switches to multi-pass mode, lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• When solar intensity increases, the DMP (Direct Multi-Pass) Solar System switches to multi-pass mode, lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• When solar intensity increases, the DMP (Direct Multi-Pass) Solar System switches to multi-pass mode, lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• When solar intensity increases, the DMP (Direct Multi-Pass) Solar System switches to multi-pass mode, lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• When the hot tap is again opened, enough useful heat is available without the need for the heat pump to switch on.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• The DMP Solar System continues to operate in multi-pass mode, again lifting the temperature in the solar circuit to the required level in multiple passes. Once the temperature of the solar circuit reaches the temperature in the top of the buffer tank, the Thermo-Differential Valve opens to discharge the high-grade heat into the top of the buffer tank. This cycle is repeated many times in one day, each time adding heat at the right temperature for immediate use.

• When the top zone is completely hot, the DMP solar system switches to heating the bottom, so the whole volume of the storage tank is used.

• When the day ends and solar intensity drops, the DMP Solar System typically still has a relatively cool zone in the bottom of the tank, so it can keep collecting heat until the sun really sets.

Solar combi-systems supply domestic hot water as well as heat for space heating, which not only saves fuel, but also allows the primary heat source to stay off during spring and autumn, which is of particular benefit with biomass systems. Using a biomass system as the only heat source requires the biomass system to operate all year round, requiring filling and cleaning even in spring and summer. Combining your biomass system with our DMP Solar Combi-System means that the biomass system can stay off for up to 180 days a year, decreasing your biomass-fuel bill and reducing maintenance.
Our DMP Solar Combi-System is specifically designed to keep the heating season as short as possible for the primary heat source, such as your biomass system. We use highly efficient vacuum tube collectors, connected directly to the buffer tank, to create a robust, maintenance-free solar thermal system, ideal for using with larger collector areas typically used in combi-systems. Our unique solar thermal system, using our patented Thermo-Differential Valve technology, ensures that high-grade heat is generated at the required temperature for domestic hot water production, so that free heat from the sun is immediately available in summer, even if you’re using a large buffer tank.