Closing Venetian blinds the wrong way round can make a 25% difference to heat loss through a window, according to a University of Salford professor speaking on BBC Morning Live. In some cases, the mistake can make heat loss worse than having no blinds at all.
Appearing on the programme, personal finance expert Iona Bain visited a specially built energy house at the University of Salford to discover cheap ways of heating the home. One tip showed the surprising difference made by spending two seconds closing blinds the right way.
Radiator heat and blind direction
Richard Fitton, a professor at the University of Salford, explained that there are two ways to close Venetian blinds – pointing up or pointing down – and one performs better. He noted that a radiator is typically positioned directly under a window, so the direction of the blind affects how rising heat behaves.
Prof Fitton said: “If we close them this way, then we can think that the heat might be rising and going in this way and being forced up against the window. Whereas if we close them this way, you have the opposite effect.”
25% difference in heat loss
Ms Bain explained that rising heat will be pushed through the blind towards the cold window if the blinds are closed the wrong way, but closed the right way, the blinds deflect heat back into the room. Prof Fitton said the difference between the two directions is about 25% in terms of heat going through the window.
He added: “The interesting fact is if you open it the wrong way or close it the wrong way, then it’s even worse than having the blind not there at all.”
Energy bill warnings
The tip comes as analysts at Cornwall Insight warned that annual household energy bills could rise by 16% in January – the largest increase for four years. Cornwall Insight predicted the average dual-fuel bill will rise to £1,999 a year on January 1, up £276 from the level between October and December, the biggest rise since January 2023.
The warning follows the October 1 rise in Ofgem’s energy price cap, which saw bills jump 4%. Cornwall Insight said the increase is driven by the escalating conflict in the Middle East, which has disrupted gas supplies to the UK and worldwide as the Strait of Hormuz shipping route has been effectively closed since the Iran war began in February. Storage levels of EU gas are at their lowest September level for 15 years, the analysts said.
