Solar chimney cuts energy usage

While energy-efficient double glazing prevents heat loss through windows, it also causes temperatures to rise to unacceptable levels in conservatories and other highly glazed rooms.

However, this is a problem that Cambridge UK renewable-energy specialist theEnergyCrowd is turning into an opportunity.

By fitting a solar chimney to the side of the house, theEnergyCrowd has been able to extract warm air from the conservatory and feed it via the loft space into the rest of the house.

As it is also glazed, the solar chimney collects additional solar energy and the top of the chimney and can reach temperatures of up to 40ºC during the winter months. As the chimney is mounted upright, it has a greater angle of incidence with the winter sun than conventional roof-mounted solar panels.

The fan that circulates the air throughout the house is thermostatically controlled to ensure that the system only attempts to draw warm air into the house when the sun is shining.

Peter Kruger, the engineer who founded, said: ’It has been good to see this system cutting energy use at a time when the recent “Big Freeze” in the UK was doubling household fuel consumption.’

According to theEnergyCrowd, the passive solar energy technology is a potential business opportunity for the secondary glazing industry, which has seen the sales of conservatories fall from a high of more than 230,000 units to less than 100,000 per annum.

Kruger said: ’With 39 per cent of non-transport energy in the UK currently being used for domestic space heating and the marginal cost of adding theEnergyCrowd’s technology to a conventional conservatory being low, this is an ideal way to add value to installations and for installers to gain a toehold in the green-energy market.’

Warm air from the conservatory is fed to the loft space into the rest of the house