Electric vehicles (EVs) are remarkably quieter than internal combustion engine vehicles, especially due to the absence of the noise produced from the gasoline engine and transmission systems. Therefore, EVs can glide across a road without contributing to any noise and air pollution.
Even though there is a noticeable decrease in sound from an EV, other ancillary noises are predominant in electric vehicles. Most of these ancillary noises, which were previously drowned out in an internal combustion engine vehicle, are now audible in the absence of engine noise.
Such ancillary noises can hamper the driving experience and also disturb the acoustics from sound systems or haptic feedback while driving the vehicle. Under these conditions, acoustic insulation in an electric vehicle is of great relevance. The acoustic insulation quality in EVs needs to be enhanced to prevent noises entering the passenger cabin from outside the vehicle and noises from the insides of the vehicle, such as the vehicle HVAC system and the vehicle electric drive system.
The acoustic and thermal insulation for electric vehicles (EVs) can be used for a variety of purposes, such as
- Passenger compartment: In an EV, functions such as air-conditioning, refrigerant compressor, and cabin heating, which are needed in the passenger compartment, are powered by the vehicle’s battery, which can strain the battery’s functioning and the vehicle’s driving range. The increase in the volume of the passenger compartment area is mainly due to the heightened need for better sound insulation in an electric vehicle. Various noises from within the car and the outside environment become more prominent due to the absence of an internal combustion engine and transmission system, which was earlier used to mask these ancillary noises.
- Rear compartment: The vehicle’s rear compartment is surrounded by rear seats and electric motors and is a crucial area for acoustic and thermal insulation. Some of the prominent areas where insulation is needed include spare tire covers, under package tray cover, and trunk lid. The luggage in the rear compartment needs to be insulated from the heat generated by the electric motor below it, raising the need for insulation covers around the trunk.
- Under the hood and battery pack: Some of the prominent areas where insulation is required in an electric vehicle include the battery pack, front load floor covering, trim lines, and cowl sponge. The battery pack of the vehicle would need greater thermal insulation to maintain the battery temperature. The battery is vulnerable to extreme weather; therefore, insulation around it is useful toward increasing its optimization while driving. There is also a need to provide adequate acoustic insulation near the electric motor to undercut its noise.
- Exterior: There are many sources of noise apart from the ones mentioned in the preceding sections. These can include various buzz, squeak, and rattle (BSR) conundrums caused by various loose parts in the vehicle, along with constant reverberated noises, due to fault in any one of the vehicle systems. Moreover, several noises become more prominent while driving an electric vehicle, such as tire and wheel liner noises, and need to have enhanced acoustic insulation.