Maximum energy efficiency for schools and public buildings

The initial situation

Schools, daycare centers, and other public buildings place high demands on the energy efficiency of modern ventilation systems. At the same time, large volumes of fresh air must be supplied to ensure a healthy and comfortable indoor climate.

Even a few additional percentage points of heat recovery efficiency can generate significant energy savings over the lifetime of a system. At the same time, the economic requirements for public construction projects continue to increase.

For the extension of the Anne Frank School in Freiburg, a heat recovery solution was therefore required that would minimize the life-cycle costs of the ventilation system through maximum energy efficiency.

The challenge

Several key objectives were important to planners and operators:

Maximizing heat recovery efficiency reduces the remaining heating energy demand of the ventilation system. Additional efficiency gains not only lower ongoing energy costs but can also enable a reduction in the required heating capacity at the design stage.

For public buildings, high-efficiency heat recovery therefore provides an important means of sustainably reducing energy consumption, operating costs, and CO₂ emissions.

The Polybloc solution

For this project, an ACCUBLOC high-efficiency regenerator was integrated into an air handling unit manufactured by Hansa Klimasysteme.

The heat exchanger was designed for a temperature efficiency of more than 87%, providing exceptionally high heat recovery. Under suitable operating conditions, ACCUBLOC can even achieve temperature efficiencies exceeding 90%.

Thanks to its high efficiency, a greater proportion of the energy contained in the extract air is recovered. This not only reduces heating costs but can often also enable smaller heating coils and other system components.

Unlike rotary heat exchangers, ACCUBLOC operates without a rotating thermal storage mass. This eliminates moving components within the heat recovery system, contributing to robust and low-maintenance operation.

Another advantage is the freedom to select the cross-sectional dimensions. While rotary heat exchangers are limited to standardized diameters, ACCUBLOC heat exchangers can be flexibly adapted to the available AHU cross-section. This facilitates integration into new generations of air handling units as well as demanding retrofit projects.

Key benefits

The installed ACCUBLOC provides significant benefits for energy-efficient and reliable system operation:

With temperature efficiencies exceeding 90%, ACCUBLOC ranks among the most efficient heat recovery systems for central ventilation systems. The resulting energy savings can be calculated for specific locations and different climate zones across Europe using the Polybloc Efficiency Calculator.

In many applications, the annual energy cost savings already exceed the investment in the heat recovery system within the first year of operation.

The freely selectable dimensions also enable optimal integration into new generations of air handling units as well as demanding retrofit projects.

Efficiency that pays off

For more than 40 years, Polybloc has been developing and manufacturing heat recovery systems for applications with the highest requirements for energy efficiency and cost-effectiveness.

With ACCUBLOC, planners, AHU manufacturers, and operators have access to a solution that combines maximum heat recovery, low operating costs, and high flexibility in a single system.