clear poly ceiling under clear laserlite roofing of enclosed deck to capture sun heat

[lilon]

Hi,

I am about to enclose a deck that is currently covered by a clear laserlite pergola with double glazed sliding doors (and blockout curtains for night). I'd like to turn it into a guest room/deck combo (not enough bedrooms in the house, and deck not used much during winter - I live in the upper blue mountains and its cold).

I thought of tiling the deck and installing a clear poly ceiling under the laserlite with a high R-value (at least R-3 if not more). The clear laserlite and ceiling would allow the sun to heat the tiles during daytime (winter sun hits the deck soon after midday) and the high R-value of the combined ceiling and laserlite would slow the escaping of the heat released from the tiles in the afternoon/evening. I could even leave the door into the house open and get the heat inside during the day time. As I said, very few days of hot whether and during those, I'll open the sliding doors.

I saw two possible products for the ceiling:

Makrolon and www.danpalon.com.au (http://www.danpalon.com.au/).

The problem with makrolon is that I couldn't see R-value higher than 2.1 (I'd like at least 3 or more). Not sure about the danpalon.

Any feedback about the products would be appreciated.

[lilon]

Update - since I get no feedback at all, I'll appreciate also any other feedback about the idea (for example, the usefulness of the proposed ceiling in both allowing the sun to heat the tiles and hold the heat; or any other aspect of the project, such as the cost effectiveness of using double glazed doors, whether or not to have full size doors, or low walls and large sliding/bi-fold windows, etc). The size of the deck is 3x5m and the laserlite goes from 2.5m at the front to 3m at the back. Its west facing, so sun from noon to evening. See below a couple of pictures of the deck before reno.

Thanks
8782387824

[intertd6]

With what you say your going to use it will be fantastic in the winter, but unbearable in the summer.
regards inter

[lilon]

Thanks,

Just to give you an idea, so far this summer we had one day only above 30 degrees. The temps for the summer have been between 16 and 24. As I will be able to open two glass walls (I forgot to mention that the southern wall will not be made of glass but a proper insulated wall) by sliding the doors/or windows, I don't expect a huge problem. However, perhaps some kind of heat outlet in the roof/ceiling will be useful.

[tricky4000]

I worked in a place that had done just this and even on cooler sunny days, the AC would be switched on. I would be careful.
The trick to effective insulation is to cover the outer side of a window (or clear roof) rather than the inner side, where possible.

[r3nov8or]

lilon, you mention blockout blinds for the double glazed doors. What will provide blockout for the roof? I think you could arrange some sort of awning above the verandah to provide darkness for sleeping and this would also double as a means of keeping heat off the roof if such a time comes. Sorry that everyone seems to be helping you keep cool rather than warm :) but the awning over the top (or, say, retractable shade cloth) will at least help darken the room along with the blockout blinds. Hope I'm on the right track...

[lilon]

Update:

Thanks for all the good pointers. I am finally about to start the project next month, but decided against the major investment of new double glazed panels. In NSW its difficult to find second hand double glazed, so I picked up 3 sets of used cedar bifolds (2.4 metre high) with toughened glass and will use those for maximum ventilation in hot days.

As to darkening the room, I am not worried about it. I am in the blue mountains so the only strong light would be from a full moon on a clear night (my guests will have to bear).

Still have not made up my mind if a clear ceiling under the laserlite (say a total of between R-1 and R-2) to allow sunshine from midday to late afternoon but losing heat at night would be a better idea than a well insulated ceiling (say R-4) under the laserlite. I guess it depends on how often I would need to use the space at night (guest room) or on cold cloudy days. Difficult to say. Also, given that the laserlite gets dirty, how attractive will it look from below?

Would appreciate comments, and also, another small question: My bifolds will have to open inwardly (they're too tall to fit under the pergola's fascia beam); does anyone know if retractable mozzi screens can go externally to the bifolds?

Thanks so much