NFRC vs. PHI vs. PHIUS Window Certification for the US

  • 1,641 views
Uploaded on

A preliminary review of the three window certifications now available for window manufacturers on the US market based on recently released info from PHIUS. This builds on a previous comparison I've …

A preliminary review of the three window certifications now available for window manufacturers on the US market based on recently released info from PHIUS. This builds on a previous comparison I've done reviewing differences in testing protocols by PHI and NFRC.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
1,641
On Slideshare
0
From Embeds
0
Number of Embeds
2

Actions

Shares
Downloads
25
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. NFRC vs. PHI vs. PHIUS Window Certification The full fruit basket? Bronwyn Barry, Assoc. AIA., CPHD Design Director - One Sky Homes July 11, 2013 Edited: Feb.26, 2014
  • 2. Three window rating systems now on US market: National Fenestration Rating Council (NFRC): •  North America based •  No minimum standards •  Simulation and Product Test Req’d Passive House Institute (PHI): •  International •  Minimum Performance Standard Req’d •  Simulation only Passive House Institute, US (PHIUS): •  US – based •  No Min. Performance Req’d •  Simulation only
  • 3. NFRC’s certification criteria: Simulation: 1. Uwindow (required) 2. SHGC (required) 3. Air Leakage (optional) 4. Visible Light Transmittance (optional) (No Min. Performance Req’d.) Verification: 1. Destructive test of window sample 2. Factory inspection Image from NFRC website: http://nfrc.org/fenestrationfacts.aspx
  • 4. PHI’s Certification Criteria: 3 Simulation Min. Requirements: 1. Uw </= 0.8 W/m2K (0.14 BTU/hrft2F or 6.7 hrft2F/BTU) 2. Uw installed </= 0.85 W/m2K 3. fRsi </= 0.7 (Varies for other transparent components, including curtain walls, roof domes and skylights. See document: Certification criteria and calculation regulations Passive House Suitable Transparent Components: http://www.passiv.de/downloads/ 03_certification_criteria_transparent_components_en.pdf) Image from PHI component database: http://www.passiv.de/komponentendatenbank/files/pdf/zertifikate/zd_northwin_vision_en.pdf
  • 5. PHIUS’s Data Certification Program: Simulation: 1. Uwindow (required) 2. SHGC (required) 3. Air Leakage (optional) 4. Visible Light Transmittance (optional) (No Min. Performance Req’d.) Image from PHIUS info document for window manufacturers – Graham Wright
  • 6. How NFRC calc’s U-window: Uf Af Uedge Ucog Aedge Acog Ucog = U-value glass Acog = Area glass Uf = U-value frame Af = Area frame Uedge = U-value edge of glass Aedge = Area edge of glass Aw = Area Window (Ucog*Acog) + (Uf*Af) + (Uedge*Aedge) Uw = Aw * NFRC requires specific IGU values for each window certification. The U-window value is therefore specific to each certification and makes U-frame values difficult to extract for PHPP use. Thanks to Christian Kohler at LBNL for formula verification.
  • 7. NFRC Therm file protocols: Ucog Boundary Condition: Boundary Condition: NFRC 100-2001 Exterior Temp: -0.4 degF (-18degC) Film Coeff: (Rs) 4.58 BTU/hr.ft2F (26 W/m2K) Emmissivity: 0.84 Temp: 69.8 degF (21 degC) Film Coeff: (Rs) 0.39 BTU/hr.ft2F (2.19 W/m2K) (Defined using WINDOW) Uedge Boundary Condition: Temp: 69.8 degF (21 degC) Film Coeff: 0.39 BTU/hr.ft2F (2.1 W/m2K) U-factor Surface: Edge U-factor Surface: SHGC Exterior (frame exterior only) Uf Boundary Condition: Interior Wood/Vinyl Frame Temp: 69.8 degF (21 degC) Film Coeff: (Rs) 0.43 BTU/hr.ft2F (2.44 W/m2K) U-factor Surface: Frame
  • 8. NFRC simulation sample results: Ucog = 0.13 BTU/hrft2F Uw = 0.14 BTU/hrft2F SHGC = 0.38 VT = 0.51
  • 9. Sample NFRC certificate: Simulation: 1. Ufactor (whole window includes frame + glass) 2. SHGC (specific to each IGU) 3. Visible Transmittance 4. Air Leakage (optional) Verification: NFRC certification requires destructive testing of a sample window and regular factory inspections to achieve full certification. Image from NFRC website: http://nfrc.org/fenestrationfacts.aspx
  • 10. How PHI calcs window U-value For certification: Uf ψspacer Af Ug Lg Ag Ug = U-value glass * Ag = Area glass Uf = U-value frame Af = Area frame Ψspacer = psi L g = Length spacer Aw = Area Window (Ug*Ag) + (Uf*Af) + (ψspacer*Lg) Uw = Aw * It is important to note that PHI uses a ‘standard’ IGU rated at 0.123 Btu/hr.ft2F, or 0.7 W/m2K, for all their certification simulations. This generates a U-window (frame + glass) output value, but allows for easy comparison of U-frame values between multiple window profiles. Specific U-glass values are calculated elsewhere in the PHPP for project-specific performance calculation.
  • 11. PHI Therm file protocols: Boundary Condition: Temp: 14 degF (-10degC) Film Coeff: (Rs) 4.35 BTU/hr.ft2F or 0.23 hr.ft2F/BTU (24.69 W/m2K) U-factor Surface: none Ug Boundary Condition: Temp: 68 degF (20 degC) Film Coeff: (Rs) 1.35 BTU/hr.ft2F or 0.74 hr.ft2F/BTU (7.67 W/m2K) U-factor Surface: Interior Uf Boundary Condition: Temp: 68 degF (20 degC) Film Coeff: (Rs) 1.35 BTU/hr.ft2F (7.67 W/m2K) U-factor Surface: Frame * This page verified by Passive House Academy
  • 12. PHI also calculates fRsi*: Exterior: Boundary Condition: Temp: 23 degF (-5degC) Film Coeff: (Rs) 4.35 BTU/hr.ft2F (24.7 W/m2K) (Cursor placed at inside edge of glass and frame) Interior: Boundary Condition: Temp: 68 degF (20 degC) Film Coeff: (Rs) 1.42 BTU/hr.ft2F (4 W/m2K) * This page PHI verified: Benjamin Krick 7.25.13.
  • 13. And Uw – Installed: •  Interior Surface temp difference allowed = 4.2K max. •  θopK = operative temperature (average temp of interior room surfaces and interior air temperature.) •  θaK = (not clear to author at this time – requires PHI verification) Uw-installed (Ug*Ag) + (Uf*Af) + (ψedge*Lg) + (ψinstall*Lf) = Aw * This page PHI verified: Benjamin Krick 7.25.13.
  • 14. What is fRsi and Uw, installed ? Passive House Certification is essentially a DURABILITY and COMFORT standard. By including requirements for Uw, installed and fRsi, PHI certification checks against interior drafts and interior surface condensation. This ensures a high level of occupant comfort and the elimination of mold growth. Got Mold? Info from PHI component Certification Criteria document: http://www.passiv.de/downloads/03_certification_criteria_transparent_components_en.pdf
  • 15. PHI Climate Certification Criteria: Only these climate criteria qualify for PHI Certification at this time Image from PHI component Certification Criteria document: http://www.passiv.de/ downloads/ 03_certification_criteria_transparent_comp onents_en.pdf
  • 16. PHI certification example: Uw = 0.75 W/m2K Uw,installed = 0.85 W/m2K Uframe = 0.65 W/m2K Frame width Ψg(spacer) = 0.024 W/mK fRsi = 0.74 Certified! Image from PHI component database: http://www.passiv.de/komponentendatenbank/files/pdf/zertifikate/zd_northwin_vision_en.pdf
  • 17. And what’s an Efficiency Class? The Passive House Institute recently added a scaled rating (phA+ to phD) to their certificate. It is based on the ratio of glass to frame and favors thinner frames which may have a higher u-value than their wider-framed counterparts.) ψopaq = ψg + (Uf x Af)/ Lg Images and info from PHI component Certification Criteria document: http://www.passiv.de/downloads/03_certification_criteria_transparent_components_en.pdf
  • 18. How PHIUS calcs window U-value For certification: Uf ψspacer Af Ug Lg Ag Ug = U-value glass * Ag = Area glass Uf = U-value frame Af = Area frame Ψspacer = psi L g = Length spacer Aw = Area Window (Ug*Ag) + (Uf*Af) + (ψspacer*Lg) Uw = Aw * It appears that PHIUS is using the same simulation protocols as PHI (EN ISO 673, 10077) with outputs structured in a similar format to the NFRC. It also appears PHIUS is calculating specific IGU’s for each frame to generate U-window ratings. This info is based on author study of current PHIUS documentation and has not been confirmed by PHIUS.
  • 19. PHIUS Therm file protocols: Boundary Condition: Temp: 14 degF (-10degC) Film Coeff: (Rs) 4.35 BTU/hr.ft2F or 0.23 hr.ft2F/BTU (24.69 W/m2K) U-factor Surface: none Ug Boundary Condition: Temp: 68 degF (20 degC) Film Coeff: (Rs) 1.35 BTU/hr.ft2F or 0.74 hr.ft2F/BTU (7.67 W/m2K) U-factor Surface: Interior Uf Boundary Condition: Temp: 68 degF (20 degC) Film Coeff: (Rs) 1.35 BTU/hr.ft2F (7.67 W/m2K) U-factor Surface: Frame * Simulation protocols are based on the EU ISO 673, 10077 testing protocols. Author assumption. PHIUS has not confirmed.
  • 20. PHIUS Climate recommendations: Image from PHIUS info document for window manufacturers – Graham Wright
  • 21. Sample PHIUS certificate: Simulation: 1. Ufactor (whole window includes frame + glass) 2. SHGC (specific to each IGU) 3. Visible Transmittance 4. Air Leakage (optional) 5. U cog 6. SHGC cog (not including frame) 7. Frame widths 8. U-frame values 9. Psi-spacer value Image from PHIUS info document for window manufacturers – Graham Wright
  • 22. PHPP inputs required for windows: Uf Lf Ug Lg ψspacer ψinstall Af Ag •  U- frame •  Frame dimensions (width of jambs, header and sill to edge of glass – Af ) •  Ψspacer •  Ψinstallation •  SHGC (or G-value) •  U-glass
  • 23. What are the differences? Simulation*Req'd Yes Product*Test*Req'd Yes Simulation*Protocol NFRC*100 Includes*specific*IGU* Yes Minimum*UCwindow*Req'd No Min.*fRsi*(Surfac*Temp.*Factr)No Min.*UCInstalled*Req'd No Yes No ISO*10077 3Coptions Yes Yes Yes Author’s Evaluation: Fitness Test | Triathlon Yes No ISO*10077 Yes No No No | 5K Fun Run So if you just want to build a Passive House… Chart based on most current info publicly available at this time. This chart does not include specific differences between NFRC 100 and ISO 10077, which vary enough to make comparison difficult. Author will revise as new information becomes available.
  • 24. Good luck! (Choose your windows and certifier ahead of time.) Thank You! Questions? Contact: Bronwyn Barry bronwynbarry67 at gmail.com bronwyn at oneskyhomes.com