Hybrid heat pump installation for Nutsschool Laan van Poot

Foundation for special primary and secondary education Lucas Onderwijs creates safe spaces where everyone feels seen, heard and appreciated. The foundation is also building a sustainable environment with attention for sustainable relationships and a sustainable climate. All-round installation partner BRI Group supports this and has been taking care of the maintenance of the climate systems at some thirty locations for several years. It also takes care of any replacements, such as recently at a utility school on the Laan van Poot in The Hague.

"The central heating boilers at this location had reached the end of their technical lifespan," says Niels Zweekhorst, BRI Group project manager. "For the replacement, the school board was looking for a sustainable alternative. To explore the possibilities for this, I engaged Senior Application Engineer Utility Frank Kroonenburg of Remeha, who recommended a hybrid installation with two central heating boilers and a medium-temperature (MT) heat pump in cascade arrangement and with storage tank. We also replaced the building management system and the 3-way valves and circulation pumps in the central heating distribution system. Just before the summer vacation of 2024, the work was completed."

Support for warm admissions

According to Zweekhorst, the choice of Remeha was a logical one. "Remeha is a regular partner with whom we regularly carry out maintenance and replacement projects. Moreover, in this case there were already Remeha central heating boilers in the school, so it made sense to stick with this brand. The quality of the Remeha products is excellent and we also like the cooperation very much." Here he refers, among other things, to the latest service, in which Application Engineers from Remeha drive all over the country to support installers with their hot take-up. "This allows us to provide even faster and better advice," says Kroonenburg, who took care of the warm survey in The Hague. Based on, among other things, the school's current gas consumption, the structural condition, the available technical space and the capacity of the power grid, he recommended a cascade arrangement with a Remeha Quinta Ace 160 and Quinta Ace 135 gas wall boiler and a Remeha Effenca MT air/water heat pump with buffer tank.

Favorable environment for hybrid

"The government has been shouting for years that we should get rid of gas, but due to grid congestion this is far from possible everywhere," says Hilbert den Boef, Sr. Account Manager Utility at Remeha. "Moreover, in the Netherlands we have a very favorable climate for hybrid. We have a very long early and late season in which the heat pump can provide excellent heating for the school building, for example. Only when it gets really cold outside do the central heating boilers switch on."

The Remeha Effenca MT heat pump is available in capacities from 20 to 40 kW, he says. "By placing the heat pump in a cascade arrangement, it is possible to achieve larger capacities as well. In the short term, devices with outputs between 50 and 200 kW will also become available. The heat pump works with the refrigerant R32, can deliver flow temperatures of up to 60°C and is suitable for both all-electric and hybrid installations. To complete the portfolio, the Effenca also comes as an HT version with refrigerant R290 (Propane) that reaches even 80°C (70°C at -15°C outdoor temperature) supply temperatures."

MiTera Plus Hybrid 

When a heat pump like the Effenca MT is placed in a hybrid system, control can be a challenge for the building owner, Kroonenburg knows. "With our updated MiTera Plus Hybrid, we offer a solution for this as well. With this innovative controller, users can in fact easily control the entire system - from heat pump to boiler(s). Moreover, the control can be completely customized. Does the building have PV panels? Then the MiTera Plus Hybrid ensures that the heat pump runs when self-generated electricity is available. And control based on CO2 reduction or costs (based on gas and electricity prices) is also possible. Also, the controller can work together with any building management system, such as in this case the Priva Blue ID system."

Switched in one day

To minimize heat interruption in the utility school, BRI Group first built and connected the new cascade setup in the technical room first. "Then we switched from the old to the new system in one day," Zweekhorst says. "We removed the existing boilers, after which the cascade setup only needed to be expanded with a buffer tank and associated piping." All the work went smoothly, he says. "Within a few weeks, we will evaluate the work together with Lucas Education. At that time, the replacement works of some other schools will also be discussed, in accordance with the MJOB and with a focus on sustainability." Here, too, Remeha is happy to provide both the installer and the school board with appropriate advice.