Hi there everyone,
Its been a while since I've posted in this thread but i'd be interested to touch base with any of the other people that chimed in who were currently building. Any updates, suggestions, revelations that you would care to share with us all?
I was back in Australia late last year to visit some family an managed to get along to a talk put on by Rick Butt of Strine environments (http://strineenvironments.com.au/) by the 'See change' organization. It was really interesting- even more so because the passive-haus fanboys from Laros technologies came along and started a bit of a friendly passive solar/ Passive-haus turf war
Rick's methodology is old school passive solar with massive amounts of single pane glazing on the northern side with window treatments, slab edge insulation to 1.0m (50mm xps foam), and his own proprietary thermally broken/thermal mass concrete pre-cast walling system. He is also skeptical about the need for MHRV systems 'passive houses just need active users' I think was the response.
I took some notes from the talk and will share the interesting points (in no particular order) here for anyone that is curious.
- In CBR an Earth coupled slab with edge insulation to 1m maintained winter temperature of 24 degrees northern (solar ingress area) to 18 degrees (southern rooms).
- Southern rooms require 150W per meter of hydronic heating input if you wish for it to be effective.
- cost of building a house is 10-15% of its lifetime cost.
- glazing- 5mm pane minimum. No cavity between panes bigger than 12mm (you get convection currents). Different sized glass in a double glazing window. Still want a thermally broken frame even for single pane windows.
-For window treatments to be effective they need to have a tight fitting pelmet, run the curtains to the floor and velcro edges to the wall to trap convection currents.
Just on the window treatment issue- I'm thinking of getting the curtains for our house made here in SE Asia as the labor is cheap. Was wondering about how effective it would be to get heavy duty bubble wrap (ala air cell insulation) stitched into the inside of the curtain to help up the R value. I wonder if the heat would eventually make the plastic air bubbles rupture- how much bulk it would add to them when pushed aside... Anyone else have DIY curtain hacks/ experiences they would like to share?