All of the requirements in Section 3.1.1 and 3.1.2 need to be met to achieve PHIUS+ Certification. The specific heating and cooling energy targets for the project will be determined by the envelope area, floor area, occupant density, and location of the project. Refer to the PHIUS+ 2018 Final Criteria Calculator to determine criteria for the project.
3.1.1 Main Performance Criteria for Certification
- Annual Heating Demand2 ≤ A (kBTU/ft2 .yr)
- Annual Cooling Demand2,3 ≤ B (kBTU/ft2 .yr)
- Peak Heating Load2 ≤ C (BTU/ft2 .hr)
- Peak Cooling Load2,3 ≤ D (BTU/ft2 .hr)
- Airtightness4 ≤0.060 cfm/ft2 envelope @50Pa
- Net Source Energy Demand5,6,7 ≤ 3840 kWh/yr/person
3.1.2 Summary of Other Requirements
- Moisture design criteria for assemblies and details (see Section 3.4 and Appendix B)
- Quality-related prescriptive design elements (see Section 3.5)
- Field quality assurance inspections (see Section 3.6)
- Contractor declaration (see Section 3.9)
- Window Comfort Assessment (Section 3.11)
3.1.3 Optional Additional Certification Badges
- Supply Air Heating and Cooling Sufficient 2
2 The space conditioning criteria are all per square foot of interior Conditioned Floor Area (iCFA). See Appendix H for details on the development of PHIUS+ 2018.
3 Annual Cooling Demand is total cooling, latent plus sensible. Peak Cooling Load target is sensible only.
Cooling criteria apply regardless of whether or not a cooling system is planned.
See Appendix C for method to evaluate when a cooling system is recommended. It is recommended in most climates especially for residential projects.
Certification staff may require that occupant-installed cooling, e.g. window A/C, is included in the energy model, even if it is not designed into the building as-delivered, so that the impact on source energy use is accounted for.
4 See detailed explanation in Section 3.2 below.
5 See Section 3.3 for further detail on alternate Net Source Energy targets for three “tiers”.
6 For residential buildings, occupancy is determined by the # of bedrooms + 1, per unit. 7 For non-residential buildings, the Net Source Energy limit is proportional to the floor area instead of occupancy. There is also a provision for “process load allowances” in some cases. See Section 3.3 for details.
3.1.4 Window Recommendations
It is generally recommended to follow the zone-by-zone guidelines on the PHIUS Certified Data for Window Performance Program page. As noted in Section 3.4 and 3.11 below, there is a “hard requirement” on window performance to avoid condensation risk, and to meet window comfort requirements.
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