The CEA Chronicle
Make Net Zero Happen in Utah
Insulation
- The energy code establishes a cost-effective minimum insulation level. A net zero building should be at least 50% better, and as much as 100% better than code minimum.
- Be sure that thermal bridging is minimized, or better yet, eliminated (no metal studs or concrete slab edges without continuous insulation on the outside).
- Careful attention to drainage planes to prevent water damage to the skin.
Infiltration
- Infiltration must be controlled, which will require exceptional detailing at the joints in building materials.
- Infiltration at operable openings must also be controlled, such as vestibules long enough for one set of doors to close before the other set opens, and with lids, to keep the unconditioned air out of the building.
Fenestration
- Evaluate the most favorable window-to-wall ratio. 25% is a rule of thumb starting point, but each opening needs to be consciously placed for energy performance as well as daylight and view.
- Optimize the thermal performance. There are systems with R-10 or greater assembly values, with SHGC less than 0.25.
- Use the free program, Window 5.2 as a tool to analyze fenestration assemblies.
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