Performance people don’t have
to hear
The rooms in which we spend our days contain many sources of noise, including ventilation systems, central heating installations and air conditioners. To eliminate intrusive sounds, it is worth choosing proven solutions that operate quietly while also supporting the comfort and well-being of occupants. Here is what should be considered when selecting a ventilation system.
Ventilation and heat-recovery systems
The primary purpose of a ventilation system is to provide a continuous supply of fresh air free from allergens and pollutants. One disadvantage of commonly used equipment, however, can be troublesome noise.
It is worth remembering that a domestic extract fan does not operate continuously, but only periodically. Annoying sound should therefore not be a reason to abandon the installation of such a device, particularly as it is responsible for properly ventilating a bathroom or kitchen.
Air-handling units
The situation is different with an air-handling unit equipped with heat recovery. This type of equipment operates continuously and should be installed in a boiler room or utility room, away from the areas used most frequently by household members.
The construction of an air-handling unit is considerably more advanced than that of a domestic fan. Its motor is enclosed within sound-damping panels and carefully insulated against noise. When choosing such equipment, however, it is important to check the sound level declared by the manufacturer.
If the stated level does not exceed 35 dB(A), the unit may be considered quiet. When it exceeds 40 dB(A), the unit can still be safely installed in a non-living area of the house, although its operating sound may become noticeably more intrusive at close range.
Insulated systems produce less noise
Insulating ventilation ducts is an effective complement to the acoustic treatment of a ventilation system. Fans are not the only potential source of noise: incorrectly selected ductwork can also generate unwanted sound. If the ducts are too narrow, the air flowing through them will produce a noticeable rushing noise. Incorrectly matched or poorly adjusted air inlets can likewise cause unnecessary disturbance for occupants.
In a carefully designed and installed mechanical ventilation system, the ducts should be insulated with a three-centimetre layer of mineral wool. This provides effective acoustic insulation and also helps prevent water vapour from condensing on the duct surfaces.
The principal supply and extract ducts should also be fitted with silencers to prevent fan noise from travelling into other rooms.
The problem with portable units
Many people use portable air conditioners and cooling appliances to find relief indoors, particularly during the summer. Yet an air conditioner operating at home or in the workplace can be just as troublesome to the ear. Prolonged exposure to its noise may contribute to fatigue and irritability.
Even if an air conditioner produces no more than 40–50 decibels, spending extended periods in the same room can adversely affect concentration and work performance. In extreme circumstances, prolonged exposure to excessive noise may contribute to permanent hearing damage.
When selecting this type of equipment, it is therefore important to examine the manufacturer’s declared sound level. The supplier should also be asked about the acoustic treatment used throughout the unit and the insulation separating the motor from its casing, which should further reduce intrusive operating noise.
Written by Michał Sitek
Source: Gazeta Olsztyńska, August 2013.
