Standard Glass in New Frame

[Horse99]

So last year I had new upvc frames and glass fitted.

I did keep some old upvc windows in property too for cost reasons.

Comparing the glass in the old and new windows I could swear that the glass in the old windows is clearer when looking out from the inside of the property.

The new glass is clean so I cannot say its smudged. Sort of very subtle effect. It doesn't show in photos. Best was I can describe it is the new glass is maybe sort of very slightly hazy compared to the old which seems clearer.

So my question for the professionals here or anyone else is whether or not this is possible? I know there are different types of glass and qualities too. At the standard range of the retail market is glass just glass or is it possible that a standard unit supplied in the past say 20 years ago is clearer than a new one purchased in 2022.

Thank you for any replies.

 

[crank39]

Your new glass is likely to be Pilkington K, it's a Low E coating on the cavity face of the inner pain, Pilkington K is old school by today's standards and classed as a 'hard coat', all hard coats had the horrible blue haze when looking through it, never spec hard coats and haven't done for years unless I'm replacing individual units in an existing frame then I'll match like for like other than that I'll spec a soft coat which are invisible and my go to glass would be Saint Gobain Planitherm total +, Pilkington do do a soft coat version called Pilkington KS but we're very late to the party with it