An air supply supplies air to multiple different inflatable devices. The air supply includes an air compressing device, and at least two pressure valves. The air supply operates to introduce air from the first pressure valve to a first inflatable device at a first pressure that is within a first air pressure range. The air supply also operates to introduce air, on demand, from the second pressure valve to a second inflatable device at a second pressure within a second air pressure range while continuing to supply air to the first inflatable device at a pressure within the first air pressure range. The second pressure and/or the second pressure range is different from the first pressure and/or the first pressure range.
