NZ Building code.
- Zone 1 is Far North
- Zone 2 Napier
- Zone 3 Palmerston North
- Zone 4 Wellington
Building Code H1/AS1 Calculation Method
12kW heater required. Based on YouTube – 1.5kW. Depends if it is per day or per hour. 12kW for 10-12 hours a day would make 12kW correct.
Heat recovery systems provide good fresh air ventilation but they are not a heating system. However, they can recover between 67–95 per cent of the heat from the inside air. Recycle hot air from ceiling areas down to floor level. Thermostatically controlled.
Increasing ceiling, windows or walls does little
Usual build cost: Around $3000 per square metre.
- Builder: Thomas Lynch, Artisan Developments
- Architectural designer: Erik Nielsen, Cadviz
- Ecowindows – Bjorn & Thomas (Windows and Ventilations Systems)
- Proclima Airtightness – Sheets under the insulation, airtightness tapes
- Ecodure flooring – Coretec luxury vinyl tiles
- Kingspan Insulation
- Harrisons Solar
- Hamish Stirrat of Fabricate Architecture
“80% reduction in total power consumption, Kingspan K17 insulated panels (Insulated Dry-lining Plasterboard for Adhesive Bonding). We added another (thermal) barrier to the exterior walls – a layer of plywood – and we have two insulation layers. Pink Batts line the walls, and then the 7mm plywood layer was laid over this, followed by the 50mm-thick Kingspan insulation.
When winter temperatures fell below 0 degrees, we tested the early morning temperature and compared it to our first project. It was 12 degrees in the minor dwelling, as opposed to 15 degrees in our full Passive House. These results were recorded without any electric heating used during the night.
Coretec luxury vinyl tiles from Ecodore Flooring were specified for the floor, providing double the normal insulation underfloor to match insulation in the ceilings and walls. These tiles consist of a cork base, PVC core and a vinyl top layer.”
Say a 6-degree delta, so a 3Kw heat pump, for 2 hours in the morning and 6 hours in the evening. 8 hours, 240w heat loss per hour per degree = 1.92kW divided by Coefficient of efficiency (4) = 500W per day of electricity required. BUT, Ventilation loses some, though 65% is recovered by the MHRV, so 1.2kW per day.
- Underfloor R5
- Wall R3
- Ceiling R6.6
- Double glazed (including warm edge spacer), thermal break, 3M film and secondary glass = 0.8 + 0.44 + 0.19 = R1.43
10-15% heat loss through floor (80% of that is through the perimeter), 20-30% through walls, 20–30% through the window, 30-35% through ceiling
Geometric features cause thermal bridging.