centrifugal force illustration

{!! $img_subtitle !!}

The Kelix uses centrifugal force in place of pumps and a compressor to move refrigerant and raise and lower its pressure.

An Oklahoman’s invention could dramatically lower the cost of air-conditioning. Like any air conditioner, the Kelix transfers heat from inside to outside by raising and lowering the pressure of a liquid refrigerant — but without the power-hungry compressor that is mostly to blame for air-conditioning’s notoriously high energy consumption.

John Kidwell, a former Air Force jet engine mechanic, got the idea in the 1970s when, he says, “it occurred to me that you could use centrifugal force to compress a fluid.” He poured water into a bucket, swung it in a circle and, as he expected, the water stayed put. Next, he laid one end of a hose in the bucket, draped the other end over his shoulder, and taped the rest to his arm. When he swung the bucket again, water was forced through the hose.

The Kelix is designed around a continuous, refrigerant-filled tube that’s coiled into two consecutive spirals, looking much like the guts of a jet engine. As the assembly spins, refrigerant moves through the tube, which compresses and decompresses the refrigerant at the appropriate times (see graphic).

Tulsa-based Kelix Energy Systems ( has built a prototype that Kidwell says uses half the electricity of a standard air conditioner. The company is raising money to build production prototypes.

Here’s how it works:

1. Cool refrigerant in the spinning evaporator coil absorbs heat from inside the house.

2. Refrigerant then flows through the return tube
to the condenser coil.

3. Pressurized by the venturi (a restricted passage), refrigerant in the condenser coil heats up further. The excess heat is then vented to the outside.

4. As refrigerant squeezes through the venturi, it
partially vaporizes and cools down — and the process begins again.