Paragraph 20
England and Wales
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.