Automatic or mechanical equipment
20. Where the health and well-being of the animals is dependent on an artificial ventilation system—
(a)provision shall be made for an appropriate back-up system to guarantee sufficient air renewal to preserve the health and well-being of the animals in the event of failure of the system, and
(b)an alarm system (which will operate even if the principal electricity supply to it has failed) shall be provided to give warning of any failure of the system.