Winter freeze at Dunham sets off fire alarm

The view across the moat towards the house at Dunham Massey, Cheshire

Extremes of weather have a habit of exposing the vulnerabilities of the Trust’s historic buildings, often in surprising ways.

A hard winter

Winter 2009-10 was Britain’s coldest winter for more than 40 years. In January 2010 overnight temperatures at Dunham Massey, Cheshire, fell to –19°C. House staff know from experience that at these times they need to be alert for burst pipes and minor floods from melting snow.
But it was a surprise for Dunham Massey’s House Steward, Katy Taylor, to hear the fire alarm go off at midnight one evening in early January. Instead of smoke or fire, she found clouds of steam billowing from a radiator which had burst due to the cold weather.

How can a hot radiator freeze?

What had happened at Dunham to cause the radiator to freeze? Previously unnoticed, at the base of each radiator, was a fresh air vent. It was the cold air entering via the vent that caused the problem.
Who could imagine that a radiator would have such an unusual feature, seemingly defeating its purpose? Research by one of the Trust’s conservation advisers revealed that this feature is part of a Victorian ventilating radiator system. In fact a nineteenth century heating engineering textbook illustrates this.
At the time, fresh air was considered healthy and invigorating. Florence Nightingale’s ‘Notes on Nursing’ describes the curative benefits of fresh air and the evils of stale air.
The late Victorians were therefore suspicious of the stuffiness they associated with new central heating systems. The ventilating radiator provided the answer with a gentle intake of fresh air (in temperate weather), while heating the building.
So, quite unintentionally, Dunham’s floods were related to the Victorians’ perceptions of health and indoor comfort, very different from those of our own age.