BMW designing heat-seeking car interiors

BMW is working on technology that can suck all the heat out of the air in a car’s cabin and turn it into electricity.

The German luxury car-maker last week provided insight into some of the future technology it is working on, including heat exchangers for electric vehicles that soak up energy that is normally wasted as it leaves the car’s cabin.

“On vehicles of today it is standard practice to simply release this heated or cooled cabin air into the environment once it has been circulated through the vehicle, despite the considerable amount of energy that has gone into bringing it to the desired temperature,” BMW said in a release outlining its most recent Innovation Day when it shows what technology it is working on.

“When the air is expelled through the rear air vents, its residual energy simply goes to waste.

“Although this effect can be reduced, for example by recirculating the cabin air, in practice it can never be entirely prevented.” However, BMW said power use on battery-powered, or plug-in hybrid electric vehicles, energy use was of “paramount importance” and should not be wasted.

“Every watt of energy that can be saved, for example in the operation of ancillary units, can be supplied instead to the electric motor to increase the driving range,” it said.

It said BMW engineers were working on a heat exchange system to draw residual energy from the air before it was released from the cabin.

“In a current research vehicle, this energy is then used to preheat air entering the vehicle heating system,” it said.

“This reduces the amount of energy needed to produce warm air, freeing up energy which can be used to drive the vehicle and thus to increase the zero-emission driving range.” BMW has also revealed it is working on developing lightweight wheels made out of a combination of aluminium and carbon fibre-reinforced plastics to help reduce the unsprung weight of its future vehicles.

According to the car-maker, carbon fibre-reinforced plastics weigh up to 30 percent less than aluminium, and half the weight of steel.

“The BMW Group is currently working on further potential applications, including the use of this material in rotating-mass components,” the car-maker said.

“Examples include hybrid aluminium/CFRP wheel rims, while CFRP’s high rigidity and low weight allow the CFRP propeller shaft on the BMW M3/M4 to be produced as a single-piece component, without a centre bearing.” The company said future BMW and Mini-badged products would also benefit from using cast-offs from the composite vehicle manufacturing process – both the upcoming BMW i3 hatchback and i8 plug-in sports coupe use carbon fibre-laced components extensively.

“For example, production offcuts can be reprocessed into “secondary” (recycled-content) CFRP, which can be used to reduce the weight of components such as seat frames, instrument panel frames and spare wheels by up to 30 per cent, with simultaneous improvements in terms of cost-efficient, environmentally friendly manufacturing,” it said.

BMW also said it would start to evolve the technology behind its i8 plug-in hybrid into more mainstream models.

“The BMW i8 is positioned right at the cutting edge of the Efficient Dynamics strategy,” the car-maker said.

“With its pioneering technology it is already setting standards, even though full-scale production has yet to begin.

The technology used in the revolutionary powertrain concept of the BMW i8 will also find its way into vehicles of the BMW core brand.”