Information about "Non continuous thermal Bridge elements"

[marta marrone]

Hi,

I would like to have some information about modeling bolts (non continuous elements) in therm 7.4.

Now i have this references:

- NFRC Simulation Manual (July 2016) page  8-77

- ANSI/NFRC 100-2014 (July 2016) paragraph "4.5.2 Total Fenestration Product" page  29

I'm not sure if modeling bolts and screws is mandatory or not. In all the references I find the verb "...shall be...", so I don't understand if it's a suggestion or an obligation.

Does some paragraph in the NFRC explain definitely the problem?

Is possible to preliminary check one node with the isotherm planes method in order to see if the presence of the screws affect the performance of the system and consequently not model it on all the nodes of the system?

Thanks.

Marta

[yal...@gmail.com]

Marta,

NFRC references ISO 15099 and thermal bridges are also referenced there.

By the dictionary definition 'shall' implies a command and instruction so it is pretty clear it is required. Fasteners in metal construction bridging thermal break components can make a notable difference.

This is noted in NFRC Manual, ISO 15099 as referenced by NFRC, and if you are designing in the United States ASHRAE 90.1 Appendix A9 also requires including thermal bridges when determining u-values by calculation or computer simulation.

Yalin

[francesco casagrande]

Hello,

I'm interested about the same topic and I have 2 questions: 

1. I've seen in the Simulation Manual (May 2015) the procedure to model the non continuous thermal bridge elements. What I have to do if the elements are not regularly spaced?

2. What about if my system has a 6 1/2" high aluminum bracket (1/4" thk plate) which passes through the joint? 

Do I have to simulate 2 different models, one with the bracket and one without it?

Thank you

Francesco