Pilkington K Glass S - any good?

n141311

Hi

I’m getting new windows fitted and had really wanted to go for Planitherm 4 Seasons but my fitter is steering me toward Pilkington K Glass S.

He tells me that the new K glass “S” is new and just as good as Planitherm 4S.

Does anyone have the K Glass S Windows? Are they any good?

The windows are going into a room that will have a lot of glass so I want to ensure there’s good thermal performance but that in the summer the room doesn’t get too hot.

S1oane

We had K Glass installed a few months back on the recommendation of our Builder and had high hopes for it.

The bedroom faces west and has a huge window and was historically a suntrap.

Appreciate the weather we’re having now is unseasonably warm but we’ve found it useless. 30 Degrees in our bedroom tonight.

Furts

Any room with a big glass area is going to get hot in summer. That is a fact of life and that is why greenhouses are good for growing plants. The type of glass can mitigate matters but will not control it. Two points for you to ponder - first you need to contact the Technical Departments of both glass companies and ask questions. Second you need to consider air flow, ventilation, opening windows, thermal mass, shade, blinds ... all as part of the design. Hopefully your Architect has discussed all this with you. If all this has been considered then the glass choice becomes a secondary matter.


But also ask a searching question - is "our builder" really competent and qualified to advise you on glass? They may be, but more likely is they have buying power, and kick backs, by using Pilkington glass. This is simply an everyday fact of business - they have their suppliers who they want to do business with.

ComicGeek

There are different characteristics of glass - there's the U-value, which is the transmission rate of heat; there's the g-value, which is the amount of solar heat passing through; and the light transmission. Any choice of glass has to take into account the priority of the room in terms of winter and/or summer conditions.

The two quoted glass specifications are completely opposite ends of the spectrum, so the fitter is talking nonsense trying to directly compare the two. The Planitherm 4 seasons has a lower g-value, so good in summer but has lower light transmission; whereas the Pilkington K Glass S has a very high g-value, so good in winter with high light transmission. But these are just two of the glass specifications available, so first of all look at what you are trying to achieve with the glass specification.