Attacking the thermal hole

A simple device could save householders £hundreds a year on their heating bills, and reduce the UK’s carbon emissions, scientists have concluded.

Environment experts at the University of Salford put Thermocill, which is made entirely from recycled plastic, through exhaustive tests in their Energy House thermal comfort laboratory, part-funded by the European Regional Development Fund.

Thermocill is fitted above the radiator and under the window board in a home. It redirects the heat under the board and through a vent vertically in front of the double-glazed unit attacking the thermal hole within the building envelope. This addresses heat loss through the window thus heating the room more and retaining the heat longer.

The scientists’ findings showed that:

Thermocill has the potential to save heating energy depending on the room setpoint temperature of between 16% at 21°C degrees and 3.3% at 23°C, thus operating efficiently at a lower room temperature setpoint which meets today’s standards.

Thermocill reduces the warm-up period in a room by up to 23% at a lower room temperature setpoint (eg, 21°C in 78 minutes compared to 95 minutes without Thermocill).

Thermocill diverts warm current towards the window and makes the air temperature in the window recess higher regardless of the room temperature, therefore not affecting the room temperature in any way.

Thermocill reduces heat loss through double-glazed windows (U-value) by up to 3% at 21°C and 1% at 23°C increasing the double-glazed unit’s efficiency.

Dr Richard Fitton, research lead at the University of Salford’s Energy House who led the research, said: “Thermocill is an interesting technology that we had not seen before.”

“We tested Thermocill by looking at a typical double-glazed window that you might find in any home. We then looked at the thermal transfer between the inside and the outside and how much energy was saved from the heating system that was used to heat up the room.

“When we were measuring the thermal transfer through the window we found about a 16% energy saving in our thermal comfort room in terms of how much heat energy was used when Thermocill was in place. Also the room heated up around 23% quicker when Thermocill was used.”

Thermocill inventor Keith Rimmer said: “The University of Salford tests confirmed everything I believed: Thermocill can revolutionise the fenestration and home heating industries.

“Thermocill saves energy consumption by reducing heat loss and doesn’t use any form of energy itself.

“It is manufactured from plastic waste including plastic bottle tops. It is truly sustainable and where fitted will massively reduce the property’s carbon footprint.

“Another aspect, which the report doesn’t look at, is that Thermocill also alleviates condensation from the internal glazed unit which is a problem of many new efficient window systems.”

Thermocill is aimed at the housing market and can be fitted retrospectively or integrated into new builds. Keith also sees Thermocill being an energy and cost-saver in multi-occupancy buildings like hospitals, hotels, homes for the elderly and office blocks.

It extends from 125mm to 250mm fitting the most common size window boards and comes in three width sizes 500mm, 300mm and 100mm, all of which can be used as multiples to fit the majority of window sizes.

The rear ventilation outlet of Thermocill is also adjustable to allow different thicknesses of decorative window board finishes – timber, MDF, plastic or conglomerate and tiled finishes from 10mm to 26mm.

When Thermocill is fitted no part will be on show apart from the outlet grill at the back of the window board.

The eureka moment for Thermocill came when Keith called at a friend’s home for a cup of tea.

“I was sitting in the lounge,” Keith said. “It was a cold night and I was looking towards the window and noticed the vertical blinds moving. My friend asked ‘What’s up Keith?’ and I just blurted ‘I’ve got an idea’.

“I could see the convection of warm air from the radiator was trying to get to the window but it couldn’t get there because of the width of the window board and the direction of the heat flow. I went to my car and got my digital thermometer and took some readings around the window area and within 10 minutes I had the idea for Thermocill firmly fixed in my head.”

Keith believes the potential for Thermocill is so great that he is now looking for a manufacturing partner or licensee to help take the product to the open market.

Keith and the University of Salford Energy House team plan to computer model Thermocill using the data to enhance its design, which will also optimise the product’s efficiency.