Peer-to-Peer Standards Exchange

The mistake is primarily related to the units, and it is precisely in the "Lb" equation in Note 3 of figure 29.4.7. The note shows both "m" and "ft" indicating that it is applicable for both metric and imperial units. However, for this equation to be correct the value of 15 shown in the denominator of the equation should be 4.6 when using metric values. This was also corroborated by the same equation used in the WIND DESIGN FOR SOLAR ARRAYS report (SEAOC PV2-2017) on page 3 Under paragraph "NOTES FOR FIGURE 29.4-7" where the same equation shows both "15" for feet and "4.6" for meters

Does anyone know if this mistake was corrected ?

Both sections in SEAOC and ASCE 7-16 are attched and the mistake is highlighted 

Bob

You are correct.  This is an error, both in ASCE 7-16 and ASCE 7-22.  It has not yet been corrected.  However, based on your question, I have put forward a request to issue an errata on this for both editions.  Thank you, for brining this up.

The mistake is primarily related to the units, and it is precisely in the "Lb" equation in Note 3 of figure 29.4.7. The note shows both "m" and "ft" indicating that it is applicable for both metric and imperial units. However, for this equation to be correct the value of 15 shown in the denominator of the equation should be 4.6 when using metric values. This was also corroborated by the same equation used in the WIND DESIGN FOR SOLAR ARRAYS report (SEAOC PV2-2017) on page 3 Under paragraph "NOTES FOR FIGURE 29.4-7" where the same equation shows both "15" for feet and "4.6" for meters

Does anyone know if this mistake was corrected ?

Both sections in SEAOC and ASCE 7-16 are attched and the mistake is highlighted 

Dear Ronald

First of all thank you for the prompt reply. Frankly it mattered a lot for the specific project I am curently involved in, since the weight of the ballast was coming to be very high. On a seperate note, do you have any idea on how to address the fact that most of the PV panels, at least the ones used in Europe nowadays, have lengths in the order of  2.4m ( 7.8 ft) as opposed to the limitation of section 29.4.3 where the maximum length of the panel is 2.04m=6.7'. My understanding is that the design might be unconservative for longer panels. What I am currently doing is still use the method for such longer panels and apply a 10% additional saftey factor to account for this fact . In case you have any input regarding this issue I would really appreciate it 

Best Regards

Bob Naja

Bob

You are correct.  This is an error, both in ASCE 7-16 and ASCE 7-22.  It has not yet been corrected.  However, based on your question, I have put forward a request to issue an errata on this for both editions.  Thank you, for brining this up.

The mistake is primarily related to the units, and it is precisely in the "Lb" equation in Note 3 of figure 29.4.7. The note shows both "m" and "ft" indicating that it is applicable for both metric and imperial units. However, for this equation to be correct the value of 15 shown in the denominator of the equation should be 4.6 when using metric values. This was also corroborated by the same equation used in the WIND DESIGN FOR SOLAR ARRAYS report (SEAOC PV2-2017) on page 3 Under paragraph "NOTES FOR FIGURE 29.4-7" where the same equation shows both "15" for feet and "4.6" for meters

Does anyone know if this mistake was corrected ?

Both sections in SEAOC and ASCE 7-16 are attched and the mistake is highlighted 

Dear Ronald

First of all thank you for the prompt reply. Frankly it mattered a lot for the specific project I am curently involved in, since the weight of the ballast was coming to be very high. On a seperate note, do you have any idea on how to address the fact that most of the PV panels, at least the ones used in Europe nowadays, have lengths in the order of  2.4m ( 7.8 ft) as opposed to the limitation of section 29.4.3 where the maximum length of the panel is 2.04m=6.7'. My understanding is that the design might be unconservative for longer panels. What I am currently doing is still use the method for such longer panels and apply a 10% additional saftey factor to account for this fact . In case you have any input regarding this issue I would really appreciate it 

Best Regards

Bob Naja

Bob

You are correct.  This is an error, both in ASCE 7-16 and ASCE 7-22.  It has not yet been corrected.  However, based on your question, I have put forward a request to issue an errata on this for both editions.  Thank you, for brining this up.

The mistake is primarily related to the units, and it is precisely in the "Lb" equation in Note 3 of figure 29.4.7. The note shows both "m" and "ft" indicating that it is applicable for both metric and imperial units. However, for this equation to be correct the value of 15 shown in the denominator of the equation should be 4.6 when using metric values. This was also corroborated by the same equation used in the WIND DESIGN FOR SOLAR ARRAYS report (SEAOC PV2-2017) on page 3 Under paragraph "NOTES FOR FIGURE 29.4-7" where the same equation shows both "15" for feet and "4.6" for meters

Does anyone know if this mistake was corrected ?

Both sections in SEAOC and ASCE 7-16 are attched and the mistake is highlighted 

Please see the ASCE 7 Wind Committee's response below:

"It is our understanding that ASCE's Committee on Solar PV Structures has discussed this issue related to the forthcoming Manual of Practice publication. When the geometry is outside of the bounds of the ASCE 7 provisions, the provisions could be used as a reasonable estimate of wind pressures, but should not be used for final design. In lieu of system-specific wind tunnel testing, the approach of using the design provisions with a safety factor may be prudent. Concurrently, the ASCE 7-28 Wind Load Subcommittee is reviewing the provisions along with recent research from FIU. It is too early to tell if the provisions will be adjusted in ASCE 7-28. The referenced research publication is located here: https://link.edgepilot.com/s/c1f5d437/bKUMSclgbEyXQkr3vFy9QQ?u=https://doi.org/10.1016/j.jweia.2025.106129"

Dear Ronald

First of all thank you for the prompt reply. Frankly it mattered a lot for the specific project I am curently involved in, since the weight of the ballast was coming to be very high. On a seperate note, do you have any idea on how to address the fact that most of the PV panels, at least the ones used in Europe nowadays, have lengths in the order of  2.4m ( 7.8 ft) as opposed to the limitation of section 29.4.3 where the maximum length of the panel is 2.04m=6.7'. My understanding is that the design might be unconservative for longer panels. What I am currently doing is still use the method for such longer panels and apply a 10% additional saftey factor to account for this fact . In case you have any input regarding this issue I would really appreciate it 

Best Regards

Bob Naja

Bob

You are correct.  This is an error, both in ASCE 7-16 and ASCE 7-22.  It has not yet been corrected.  However, based on your question, I have put forward a request to issue an errata on this for both editions.  Thank you, for brining this up.

The mistake is primarily related to the units, and it is precisely in the "Lb" equation in Note 3 of figure 29.4.7. The note shows both "m" and "ft" indicating that it is applicable for both metric and imperial units. However, for this equation to be correct the value of 15 shown in the denominator of the equation should be 4.6 when using metric values. This was also corroborated by the same equation used in the WIND DESIGN FOR SOLAR ARRAYS report (SEAOC PV2-2017) on page 3 Under paragraph "NOTES FOR FIGURE 29.4-7" where the same equation shows both "15" for feet and "4.6" for meters

Does anyone know if this mistake was corrected ?

Both sections in SEAOC and ASCE 7-16 are attched and the mistake is highlighted