I came across one new product at BRE’s Onsite 09 event, which was a new type of energy saving glass being marketed by Pilkington. It’s made in Japan, by Nippon Glass, owners of Pilks, and it consists of a two panes of glass separated by a vacuum gap of just 0.2mm. In this country, it’s being aimed fairly and squarely at the listed building/Georgian sash window market, because you get a very good U value from it (Centre Pane value 1.4) yet you can’t tell it’s not single glazing.
Well actually, you can, if you look closely. You can’t see that it’s two panes of glass, but the 0.2 gap has tiny black spacers located within it which you can see if you look close up – they appear to be a series of black dots. If the vacuum fails, the spacers fall out, so you have a visible clue that the unit is no longer working. But of course the units won’t fail. Will they?
The units are made up before the vacuum is applied. Each unit comes with a little grommet through which you can suck out all the air. There is a minimum unit size of 0.4m2, so a sash window will have to be done in one and glazing bars applied afterwards. But that’s not a big problem.
It looks as though they have got a product which can provide good energy efficiency and yet satisfy the English Heritage/Conservation Officer lobby. At around £300/m2, it will cost, but if done as a package of overall window refurbishment or replacement, it’s not that prohibitive. Just a shame they’ve given it a horrible name: Pilkington energiKare. I’m really getting to hate inTerCaps, aRen’T yOu?