Using Landvac vacuum glazing in modern casement windows

[siggy_7]

Hello everyone. I've got some Landvac vacuum glazing units on order which I plan to fit into some new accoya windows for an extension I'm building. The rest of the property has relatively tired timber framed double glazing (stormproof casement style) and I plan to make and fit similar windows to those I'm going to be making for the extension to the rest of the house in the future. I've gone the vacuum glazing route partly because of the superior thermal performance even compared to triple glazing without having to go super-thick on the units and partly because I just like the high-tech nature of the product.

The query I have, particularly for those in the window making business, is whether it's necessary to get the Landvac units made into a thicker glazing unit (this is called Landvac Optimum (or hybrid), where the double glazed vacuum unit is used in place of a single outer pane of an otherwise conventional double glazing unit) or whether I can just fit the thinner (8.3mm unit thickness) units into the sashes. As the window design is a stormproof casement with friction stays and espagnolette openers, the sash will need to be relatively thick sectioned anyway, but I can accommodate this just by having a relatively shallow glazing rebate of say 25mm or so and a deeper inner frame section. The supplier mentioned that the hybrid units are made to achieve BS1279 compliance, without elaborating what this is and why making up the hybrid unit would help. Any pointers much appreciated. Thanks in advance!

 

[HOJ]

where the double glazed vacuum unit is used in place of a single outer pane of an otherwise conventional double glazing unit)

I don’t really understand your statement, could you clarify, are you dealing with a constraint, can’t be a listed building if the windows are storm-proof, having said that it could be, been there done that....

From my experience I have made some notes outlined as follows:

I made some windows last year, for a listed building, but used the Fineo glass units rather than Landvac, having had samples of both, client didn’t like the Landvac unit with the getter plug being visible.

The primary reason for our use of these units was to keep the size of the timber for the frames and casements as slim as possible, and to replicate the originals as close as possible, which were all single glazed. we only used these units as the only other option was the usual “slim” glass units, which in my opinion are a liability.

Another reason for the choice was the claimed acoustic performance as the property is on a busy town road.

I would suggest by using these particular glass units, in a standard, modern, storm-proof, stock size frame may look odd and be overwhelmed by the visual mass and effect of so much timber, along with the eye watering cost in comparison to a more readily available cheaper DGU, that if there is an issue, can easily be replaced, rather than, with the Landvac units, paying and waiting for a boat from China to arrive.