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verified by Energy Saving Trust Thermocill Limited


Product Description

Thermocill Ltd. have developed an innovative passive energy efficiency product called Thermocill placed underneath a window with a radiator. It replaces the standard window board with a device which looks similar but has a channel to redirect warm air from a radiator underneath a window, up towards the windowpane. This creates a wall of warm air adjacent to the double-glazed window.

The wall of warm air generated by Thermocill is designed to reduce the amount of heat loss through the window, thus reducing the dwelling’s heating demand. Raising the temperature around the window frames is also likely to reduce problems associated with condensation and moisture.

Verified Claims

Claim: Energy per room
The energy required to heat a room is reduced by up to 14% with the addition of a Thermocill unit to a window above a radiator.

Caveat: The values are based on a 9-hour heating cycle from experimental work carried out at the Salford Energy House on the original Thermocill design. This assumes a room with double glazed windows, a typical external brick wall construction and a temperature set point of 21°C. Different temperatures and configurations may produce higher or lower savings.

Explanation: These savings are based on testing carried out at the Salford Energy House on the original Thermocill design. Computational Fluid Dynamics simulations demonstrate the optimised new design improves the performance of Thermocill with respect to air flow rate and temperature at the base of the window which could potentially improve the energy savings for a room.

All statements are correct as of November 2020 and valid for 12 months.

These product claims have been Verified by the Energy Saving Trust

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