Keeping a passive house cool

[Alan Ambrose]

@Russdl

 

Did you use any other forms of solar gain mitigation e.g. low-g glass, or only external blinds? Also, did you see any verified shading numbers from Phantom Screens or did you take them at their word?

 

 

BTW thanks for your post - in my pre-build calcs with PHPP, I've come to the theoretical conclusion that I can focus only on lowish-g glass (64% transmittance, 35% solar gain) and external blinds to bring down the overheating risk substantially.

Edited August 12 by Alan Ambrose

[Russdl]

Just the external blinds and I took their word for it, largely due to a healthy dose of naivety, but it all seems to have panned out ok. We went for the ‘premium solar - 80% UV block’. 
 

In the picture below the window on the left has the blind down, the sliding door on the right has the blind up. 
 

[mike2016]

I directed the Architects to improve the overheating score in PHPP from 5% based on local weather data (Dublin, Ireland). Adding Brise Soleil improved it to 2% and opening roof lights dropped it to 1%. However with climate breakdown I asked about changing the climate location to London and even with these mitigations it drove it up to 13%! I'm installing Air to Air heating/cooling with 4 internal cassettes and hopefully this and passive stack cooling in the evenings will help mitigate this risk for a decade or so......

[Alan Ambrose]

@mike2016 That's interesting - how wide are your brise soleil? When you say '4 internal cassettes', are those the ceiling mounted ones, kind of like these below? BTW feedback from things that have worked well for people who have finished their builds is invaluable for people like me that are still in the pre-build stage.

 

 

 

[mike2016]

The brise soleil are each the width of the 3 main upstairs windows and come out about a meter from the wall, the windows are 2 meters high. Internal cassettes are the nice wall mounted ones more typical in very small offices / homes, rather than ceiling mounted and I hope to put them above the beds when I get to 1st fix so they blow over the bed rather than onto it in case it needs to be kept on overnight for a good sleep! 

 

 

[Alan Ambrose]

Huh. neat, thanks.