Reducing HVAC Noise
Heating, ventilation and air conditioning systems (HVAC) can become pretty noisy when in use. When used in hotels, HVAC systems can keep customers awake or even distract speakers in conference rooms. Although some air conditioners are noisier than others, proper installation of the systems ensure they run smoothly and produce less noise.
Engineers installing HVAC systems therefore have to find a way of keeping the residential and commercial HVAC systems silent so they do not make distracting noise when running. Noise attenuators, also called sound attenuators or mufflers, are used to keep the systems silent.
What Causes Noise in the HVAC System?
There are many reasons why HVAC systems can become noisy. However, system can still make noise even when new. This is because as the air is being transported through the ducts, vibration of the system causes noise. Also, as the fans rotate to move air, they produce noise as the air vibrates and the fins move.
As air changes in the system, pressure drops and noise is produced. Another major cause of noise is loose fixings such as bolts and nuts vibrating to produce loud, annoying noise.
Types of Noise Attenuators for HVAC Systems
There are two main types of noise attenuators used to silence HVAC systems. They can either be cylindrical or rectangular. Cylindrical attenuators are fitted in the ducts to silence noise from the inside. The rectangular attenuators are fitted over the HVAC system. Both of the attenuators use the same principle in noise reduction in the HVAC systems.
Rectangular attenuators have dissipative silencers that deliver acoustic energy in contact with the sound absorbing media inside it. The round attenuator comes with a head that spins and a cone shaped tail. The circular attenuator is also double walled.
Inside the interior wall is the sound absorbing insulation that helps keep the sound produced to the minimum. The attenuators reduce the noise but also maintain the pressure changes in the HVAC system so air flows through the system with ease.
How Does a Noise Attenuator Work?
Noise attenuators are used as a wholesome part of a HVAC system rather than in isolation for the best performance. They are used when the system is being installed for the best effect instead of adding them later.
Noise attenuators have sound absorbing insulation inside to keep the sound down. Acoustic insulation inside the noise attenuator contains millions of air pockets that absorb the acoustic energy as it passes, reducing the noise.
The insulation inside the attenuators vary in thickness depending on the frequency of the sound produced. Increasing the length of the attenuator enhances sound attenuation, affecting the pressure in the HVAC system.
Regular maintenance of the HVAC system is carried out to reduce noise. Maintenance ensures there is no loose fittings in the maintenance system that could significantly increase the noise.
Looking for information about air conditioners? Contact us to find out more about HVAC systems and how they work.