Avoid noise from heatpump outdoor
Helpful guide for private builders
The Bavarian State Office for the Environment (LfU) has published a guide to dealing with noise problems caused by the installation of air-source heat pumps in private houses. In this connection the authority examined individual components of a heat pump regarding noise. Fans are not the only source of noise, but they are responsible for ninety percent of noise problems. During the preparation of the guide, it also came to light that there are considerable differences in the quality of individual products in terms of noise. After all, if all components of an air-source heat pump are optimized in terms of noise, the sound power level should be no more than 50 dB(A). In fact, however, the sound level of equipment on the market can be 70 dB(A) and above.
Mr. Zenkel on humming search
Customers are calling building-biologist Oliver Zenkel whenever they hear very quiet sounds. The hum is imperceptible with normal hearing. Particularly disturbing is the monotonous and recurring frequency. The person concerned enters a feeling of helplessness. Mr. Zenkel has adjusted to the soft tones and plugged a headset to the sound level meter as technical reinforcement. How the search for the hum can succeed, describe the following examples.
the highway bridge is the cause of the humming
For months Roland Wernstein (Germany) examines an annoying buzzing sound in his neighborhood: the heating system, bass from the neighborhood, truck engines, vibrations caused by rail or air traffic were suspected, but were rejected. The end of March 2016 he took time for the facts check: the humming was heard only at night and when the wind from the southwest, recalled a distant diesel engine running and had short, miscellaneous long interruptions.
The negative effect of infrasound on human health is controversial in the permitting of industrial installations. The scientific evidence is thin so far. Researchers at the Ludwig-Maximilian-University Munich (LMU) could now prove that the inner ear needs a relatively long time to recover from exposure to low-frequency sound. “The recovery time is longer than the duration of the load,” says researcher Dr. Drexl of the Department of Neurobiology at the LMU. Continue reading
soundproof-windows as “pixel-windows”
(Hamburg) The Hanseatic city tried long to resolve the conflict between downtown development, commercial development and road noise. With the housing industry was an “Alliance for Living” received. The urban sprawl of the outher regions should be avoided and existing green spaces in the city protected. Absolute priority is to focus on infill and brownfield sites. Downtown projects, however, are inviteable in the vicinity of roads, industrial parks and sports facilities. The design challange therefore is to avoid the noise and air pollutants.
The evaluation of the strategic noise mapping revealed that road traffic is the main source oft the noise pollution. Small-scale activities were carried out: intersection modifications, whispering asphalt, speed reduction. A truck-driving ban is in principle possible, but would have to be connected to a truck management system. A reduction of speed to 30 km/h at night time is also included in the concept, but after calculation provides only 2-3 dB noise reduction. Seen in sum the above mentioned noise avoidance strategies are not enough and must be supplemented by project-related activities. Continue reading
SPL means sound pressure level. In the following article you will read about basics of SPL-measurement. Noise is caused by vibrations of a sound source, such as cords or the loudspeaker diaphragm, and requires for its propagation, a medium, such as air, water or solid bodies. The vibrations of the noise source are transmitted to the medium. These vibrations and pressure fluctuations in the air can perceive our ears as sound. The fullness of what a person can hear is primarily determined by the volume and pitch. Continue reading
Combined heat and power (CHP) is used to generate electricity and provide heat as a waste product. An energy efficiency of over 90% is predicted by the vendor. The electricity-generating engine is fueled primarily by gas. The issue: larger biogas-plants are mostly in massive buildings at a distance of more than 500 meters to the nearest residential area. Smaller plants move ever closer to the vulnerable housing and are housed in part only thirty meters away. Micro-CHP will be even in the basement of homes, schools, hotels and commercial facilities.