In the Nether­lands, around seven million house­holds obtain their energy from natural gas. The market for hybrid heat pumps is booming, as they are highly effi­cient and user-friendly. The heat pump draws its heat from the outside air, even down to sub-zero temper­a­tures. When the air temper­a­ture is too low, the system gets addi­tional heat from the gas boiler. Domestic hot water is always supplied by the boiler. This makes the system reli­able in all condi­tions. Customers can also choose to change the point at which the boiler kicks in based on the energy prices to save cost. In the past, it was common to sell the heat pump in combi­na­tion with a boiler, to ensure that they were compat­ible.

The HP-M 25i: The first hybrid heat pump that can work with any boiler – regard­less of type or brand. (Photo | Itho Daalderop)

Itho Daalderop, a manu­fac­turer of heating systems for private house­holds and the market leader in venti­lation systems and ground source heat pumps in the Nether­lands, is changing the status quo. The HP-M 25i is the first hybrid heat pump that can work with any boiler – regard­less of type or brand: “Our greatest concern was to ensure that our product could be inte­grated seam­lessly into any existing house and any existing heating system, without compro­mising the level of comfort. This is some­thing we have achieved,” Alex Huizinga, Project Manager of the Inno­va­tion Depart­ment at Itho Daalderop, proudly explains.

Complete control

But how? The heat pump real­izes its full poten­tial all through the year, as it can use its fully inte­grated control system to switch on its secondary energy source, i.e. the gas boiler, depending on require­ments. At the same time, that was the biggest devel­op­ment chal­lenge. For the heat pump and gas boiler to work together seam­lessly, it had to be possible for the heat pump to flex­ibly adjust its settings to any rele­vant boiler – of which there are many different types on the Dutch market. Itho Daalderop, together with ebm-papst Heating Systems, spent just under a year devel­oping and testing the right soft­ware.

“ebm-papst is our long-standing partner, and they have a lot of know-how when it comes to heating systems and gas boilers, as they work with a lot of compa­nies that manu­fac­ture these prod­ucts. That was a signif­i­cant advan­tage for us,” states Huizinga. The two compa­nies made partic­ular use of the winter in 2018/2019 to test how the control system worked in prac­tice in private house­holds, and thus, to opti­mize the algo­rithms step by step. Conversely, the corre­sponding hard­ware – the circuit board – was sourced from ebm-papst’s stan­dard reper­toire.

Silent heat

Smart duo for hybrid heat pump: The 900H series control plat­formb and the RadiCal. (Photo | ebm-papst)

A second product from ebm-papst, the RadiCal® centrifugal fan, ensures that the heat pump runs very quietly. The fan draws the cold air from outside into the heat pump, moves it around and, through a heat exchanger, releases its heat into the inte­rior of the house and the water circu­la­tion system – all at a very low indoor noise level of 38 dB. The “Fan Night Mode” func­tion reduces the speed of the fan by 25 percent during the night. In this way, if neces­sary, everyone in the house can get a good night’s sleep. 

Good for the envi­ron­ment

Customers who purchase the HP-M 25i are helping the envi­ron­ment, as Itho Daalderop has adopted a leading role in the fight against climate change in the Nether­lands. In contrast to conven­tional models, the hybrid heat pump comes with a hermet­i­cally sealed refrig­erant circuit – much like a common refrig­er­ator –, thus reducing the risk of escaping fluo­ri­nated green­house gases during instal­la­tion. What’s more, as the heat pump obtains energy from both the outside air and the exhaust air produced by the central venti­lation unit, reducing gas consump­tion even further. In turn, this is also good for the personal wallet.