CareEnvironmental monitoringStorageTemperature

Autumn’s here: Why turning on your radiators could be turning off your revenue stream

old radiator with peeling paint
Turn off radiators under artwork

Radiators – oil filled heaters – storage heaters – under-floor heating – at this time of year, the chances are that your office has some form of heating (and I do hope so!) and that you’ll be discussing whether or not to put it on. Perhaps it will go on for a few hours in the morning and a few more in the afternoon, if you work in a small cost or environmentally-conscious office, or perhaps you work in a space where your office becomes a blast furnace, with the windows open and the staff in t-shirts, from October 1st until March 31st.
No matter which heating style you live with, it probably won’t suit your company collections unless they’re in a dedicated climate controlled location. Most offices with historical collections fail to prioritize them and so store them wherever there’s room – the attic, the basement, cupboards, open shelving in offices.
So why is heating a problem? How on earth can being warm entirely ruin collections? Well, I’ll explain, and as it’s nearly my lunchtime I’ll use a few food analogies. Imagine putting two litre bottles into the freezer. One contains water, one contains alcohol. They’d both freeze, but one would expand more than the other. As they melted, they’d contract back to their original sizes. Now, think of the way in which pasta absorbs water, and how it dries out again when the water is removed. This happens, to a greater or lesser degree, to everything in a collection.
Take a traditional oil painting as an example. Usually, oils are painted in many layers of differing paints over a canvas, which is usually made from cotton, linen or hemp. The canvas will have been initially treated with a layer of gesso, comprised of linseed oil and calcium carbonate, applied over a rabbitskin glue ground (called a ‘size’). The whole is stretched over a wooden frame. The painting might be varnished after completion, before being inserted into a plaster and gilt frame. On average, you therefore have at least nine different mediums – canvas, linseed oil, calcium carbonate, size, wood, varnish, plaster and gilt, not to mention the paint and everything that it’s made from. ALL of these things will absorb and lose heat and moisture and, crucially, this happens at different rates, like the frozen bottles and the pasta. As they do this, they expand and contract, again, crucially, at different times. Back to the food analogies – imagine a flaky pastry, with different layers becoming larger and smaller at different times – a smaller bottom layer rucks up the larger top layer; a larger bottom layer stretches and cracks the smaller top layer. The end result is an oil painting with cracked, flaked paint, shrunken or loose canvas, warped canvas frame and lost chunks of gilt plaster – I’m sure you’ve all seen one somewhere. The paintings in the worst condition are usually those still hanging over the Victorian fireplace, which expanded and contracted hugely every day in the fierce heat generated.
Every single thing in a collection is susceptible in one way or another. Some items take decades to show degradation while others have visible damage fairly quickly. All the time that your heaters are cycling on and off, causing wide temperature fluctuations, they are causing damage. Moving items away from fluctuating heat sources can help, as can creating micro climates by boxing – best of all is a temperature controlled room, or one which has no heating or windows and so has a more even, less spiky temperature chart.
Once your items are damaged they are less useable for advertising campaigns, merchandising, corporate gifts, inspiration, research, image licensing and heritage strategies. Do take steps to protect your company’s valuable history – moving collected items away from heat sources is a simple, easy thing for you to do.