Building interior windows insulation panels

[MM]

For years I have thought about building my own insulation panels for my house windows, as shown here:

But that chap uses heat-shrinkable plastic to cover the frames.

I always intended to cover the frame with a thin sheet of hardboard both sides, then fill the space within the 'box' with some insulating material, such as loft insulation. These panels would only be in place during the night in winter, say from 4:00 pm till 8:00am. They would be light in weight, so easily placed or removed. During the summer they could be stacked in the garage.

Question 1: Is it better to use the heat-shrink method with air as the insulation medium, or to fill the void with insulation material?

Question 2: What would be an alternative suitable material to fill in the void?

MM

[fred]

In article , MM writes

When things have sunk so low it may be best just to hang yourself from the curtain rail.

[John Rumm]

Any significant volume of air will be able to setup convection currents that will lower its effectiveness.

Fix a piece of solid PIR foam to the board.

[MM]

Ah, good idea!

MM

[MM]

Is that something like Celotex?

MM

[Tim Watts]

On Friday 08 November 2013 15:38 MM wrote in uk.d-i-y:

Yes. Or Kingspan, Ballytherm and ahost of other branded version :)

[harryagain]

I have already done this with insulated shutters, all windows. Plus lots of other stuff. I have a zero heating bill. Pix here.

I used celotex sealed into the box with canned foam. Makes it very rigid so only light construction needed.

[John Rumm]

Yup, or Kingspan, Ecotherm, "seconds" from any number of places. Dense yellow foam usually with foil on at least one side.

[dennis]

If the gap is more than about 20mm it won't work very well as convection will start up. Hence the 20mm gap in double glazing.

PIR stuck to a bit of painted MDF with hinges on the sides, they used to fit shutters in the past to keep warm.

You can use thermal curtain liners and/or thermal blinds too.

[stuart noble]

IIRC "loft insulation" (Rockwool etc) is far from light

[ss]

What about making a frame and filling with polycarbonate sheeting I think you can get double or triple layer, dont know about the insulation value but would still let light in.

[dennis]

Fitting a second double glazed unit would (approx) halve the heat loss and reduce the sound by a lot if its about 100mm from the outside window.

[Judith]

When things have sunk so low it may be best just to hang yourself from the curtain rail.

LOL

[Brian Gaff]

I was just thinking that. I mean, covering the windows with hardboard???

Brian

[stuart noble]

Only at night. No different to shutters really

[MM]

The pics are VERY impressive!

MM

[MM]

I'm not unduly worried about the fact that the panels I envisage won't let light in, because they are only for winter use during hours of dusk and darkness. However, I may cover the street-facing side with some net curtain material so that it doesn't look like the house is condemned when I'm away.

MM

[MM]

Ah, now I was planning to butt the panel up against the existing double-glazed window frame, but you seem to be suggesting that it would be better placed just inside the window recess?

MM

[Nightjar]

Except that proper shutters would look better.

Colin Bignell

[Nightjar]

I wrote that before looking at Harry's photos.

Colin Bignell