Amy Silverston weighs up draughts versus alternative problems

A couple of years ago the size of heating bills and the billowing curtains on winter’s nights prompted us to get the draughty sash windows sorted out. Various companies came round to quoteand we were given theirvarious opinions on the subject.

Cutting Draughts to Reduce Bills
Most major on the reduction of draughts and how this will save on heating costs. You can inset brushes around the window units to stop the draughts, leaving the glass as is. Or you can reduce the amount of heat loss through the glass by changing it for double-glazed units which may featurea gap visible between panes, or appear like a single pane. Double glazing means more, and therefore heavier glass, which means changing the sash weights. Few seemed keen to do this though a swift online search comes up with weights costing about £1 per lb. which doesn’t seem a huge expense. Perhaps it is a fiddly job they would rather avoid.

Because these are the factors offered for consideration, the choice becomes a matter of setting the cost of each option against how much one can anticipate saving in heating bills. We decided to leave the glass as it was because the cost of replacing it was going to cost more than we would recoup.We didn’t know there was anything else we should be considering.

The house was instantly more cosy after the work was done in the early autumn. But then, when the weather got really cold, we started to experience a side effect that had not been mentioned by most of the companies, or at best skated over in passing: condensation. It wasn’t much initially, but after a few weeks we would wake up every day to over15 windows in our three-storey house running with water worse than a London bus packed with school children on a cold, damp winter’s afternoon. Then the wooden window frames started to go black all around the glass with a slimy mould. When the heating was off the house felt utterly chilled and the place felt strangely uncomfortable in a way one couldn’t quite describe.

Without draughty windows the supply of fresh, dry air had been cut off. Cooking, using the bathroom, hanging laundry on the clothes horse, and breathing – all put moisture into the air that had nowhere to go.

Using a Dehumidifier
The problem was solved by the purchase of a large dehumidifier. Whatever they say, dehumidifiers are not silent – they contain a fan and effectively a reverse refrigeration unit. Buy a larger one than suggested for size of house/flat so it will not have to work as hard and the fan can operate at a slower speed, and run it the least intrusive times of day.

We tried it in different places around the house and found it worked best on the very top landing, at the highest point inside the house, even though this is furthest from the kitchen – but, when you think about it, the water vapour in the earth’s atmosphere – clouds – are up there, not down here. Same principle.

For the first week it pulled litres and litres of water out of the air. The house lost that uncomfortable feel that we realised was clammy, damp air. It also heated up faster. We learned when to put it on – usually in the evening, or when we had washing on the clothes horse, or if the weather was damp – and to tell when the air in the house was getting water-laden. Condensation is worse when it is coldest outside, because the temperature contrast between the air inside the house and that of the window glass – the outside temperature – is greatest.

Mould and Spores
The cure for the black mould on the wooden window frames is a solution of borax. A paint brush is most effective for cleaning off the mould as it gets into the corners, where the glass meets the wood and around the window catchesmuch better than a cloth. The borax (sold in the Aladdin’s cave hardware shop towards the top of Kentish Town High street; other places sell borax substitute) seeps into the wood and gets to the root of the mould. Bleach works on mould growing on the surface of plastic or ceramic – i.e. on plastic window frames and in bathrooms.

We experienced firsthand how damp (in this case caused by a leaking roof flashing) can cause irritant spores. Whilst the room’s occupant was unaffected, I became unable to go in to read bedtime stories because within minutes my eyes would smart and water, to the point I could not keep them open. The roofer recognised the problem and advised washing the water-stained patch with bleach to kill the spores. When the cause of the damp was cured, the problem went away. I have met people with acute condensation problems who suffer the same symptoms.

Drying Clothes
Online debates rage about the most cost-effective means of drying clothes indoors. The evidence seems to be on the side of dehumidifiers, though tumble driers are faster. We have both so have no particular axe to grind. The Daily Telegraph’s property expert column reported that for every unit of electricity used, a dehumidifier emits two to three units of heat.

The tumble drier makes towels soft, but more clothes and sheets will fit on a good clothes horse. Often these take a lot of space and do not hold much, but the Leifheit 81436 Tower 190 has 19m of drying line, requires only a square metre of floor space (it will fit in a shower cubicle), takes two washing machine loads of wet laundry and packs flat when not in use. They are robust – our first one lasted 12 years – and cost about £50 on Amazon. I get two sets of double and king-size sheets, duvet covers and associated pillow cases on it. The dehumidifier will get it dry throughout the day. The clothes horse and dehumidifier are both on the top landing, where it sucks in moist air from around the laundry and blows dry air back out at it.

Apart from running cost arguments, tumble driers wear out clothes: that thick layer of lint on the filters has come out of the clothes, wearing the fabric thin. Personally, I don’t like the way clothes come out of a tumble drier in a creased-up mound. They dry flat hanging on a clothes horse as they do on an outside line.

A 2012 study by the Mackintosh School of Architecture looked specifically at the possible problems caused by drying clothes indoors, which they found contributed a third of the moisture in houses. 75% of households had moisture levels which could lead to dust mite growth. There was also a strong association between drying laundry (machine-load can hold a couple of litres of water) and mould spores. A spore known to cause lung infections in people with weakened immune systems was found in 25% of the homes sampled.

The researchers wanted to see dedicated drying areas incorporated into new housing, harking back to the days of airing cupboards. A DIY alternative is to put a dehumidifier in a small room with the door closed whilst drying clothes, or inside a large wardrobe.

Is Double Glazing Any Better?
Going the whole expensive hog and replacing entire windows with double-glazed units will make the place warmer at first and minimise condensation. However, because the air has to be extremely humid for condensation to occur inside double-glazing, the house can get very uncomfortable before a problem is visible, as I discovered when visiting a friend who had done most of the windows in her house. I recognised the clamminess as soon as I walked in, then realised she had a hacking cough – but only when inside her own house. When the room I was sleeping in had condensation in the morning on the beautiful new hardwood framed, double-glazed windows the cause became clear.