| 摘要 |
<p>The electrical heating panel, for caravans and other small buildings etc., consists of resistance heating wire sandwiched between two plastic foils to give a heating sheet. The sheet is in turn sandwiched between two sheets of plywood each coated with phenol formaldehyde resin. The rear plywood sheet has holes to reduce its thermal insulation value, whilst the ront sheet has none. An earthed aluminium foil is located between the heating sheet and the front plywood sheet. The whole assembly is held together at its edges by a U-shaped frame. The heating panel can be located behind the caravan's bench seats.</p> |
