Chamber: Headless installation of RES can disrupt the statics of buildings and increase noise

Update: 27.03.2023 11:04

Prague – Reckless mounting of any roofs with large solar panels can endanger the statics of buildings, and oversized heat pump outputs can increase noise levels above permitted limits. The Czech Chamber of Authorized Engineers and Technicians Working in Construction (ČKAIT) drew attention to the increasing problems that accompany the current strong interest in renewable energy sources. She recommended a professional assessment before installation. Interest in renewable energy sources in the Czech Republic is growing rapidly, the number of installations of photovoltaic power plants increased almost fourfold last year, and the installation of heat pumps also increased significantly.

“Of course, we welcome the direction our company is taking on the path to greater energy self-sufficiency. However, we point out that energy equipment requires professional training and care in the long term. Only in this way will their involvement lead to the satisfaction of the builder and his surroundings,” noted ČKAIT Chairman Robert Log.

According to the chamber, the interested parties should check the statics of the building in addition to the fire safety measures before purchasing the photovoltaic assembly itself. “Not every roof can withstand the load of solar panels. And it’s not just their weight,” the chamber pointed out.

An assessment of the state of the roof structure by a structural engineer according to the chamber will often reveal a number of possible risks or weaknesses, since a large part of the constructions were created at a time when similar loads, such as photovoltaic devices, were not expected. “Based on the dozens of cases we have evaluated so far, pitched roofs with trusses work better for completed or older buildings. However, the situation is different for flat roofs of buildings and light roof coverings of halls. Previously, roofs were designed economically only for the effects of the weight of snow and pressure or wind suction. Therefore, they usually do not have a reserve for additional loads,” explained Luděk Vejvara, chairman of the ČKAIT regional office in Pilsen and structural engineer.

The chamber also encourages a qualified approach when installing heat pumps. At the same time, it warns in particular about the often oversized performance of equipment, which may not bring the required savings, but can, on the contrary, increase noise. In this context, the chamber pointed out that it is also necessary to observe hygienic noise limits during installation. According to the state methodological aid, the equipment should be located so that its noise and vibration level does not exceed the permitted value of 35 decibels at night and 40 decibels during the day in a protected area.

“We appeal to designers, technicians and, above all, sellers and assembly companies to take this aspect into account. Relaxing the conditions for the installation of renewable energy sources does not mean resigning from fire safety and other professional aspects, nor from the public interest and good neighborly relations,” added Špalek .

In the Czech Republic, 33,760 photovoltaic power plants with a total output of 288.8 megawatts (MW) were put into operation last year, which is a year-on-year increase of 366 percent. The number of installed heat pumps also doubled, last year Czechs purchased around 60,000 of them.