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Curtain Wall Design

Curtain Wall Design

kodstruct

(Structural)

(OP)

20 Mar 15 23:37

Hi there,

Lately I have been getting calls from contractors to design curtain walls and storefront systems for them So I am thinking to start my practice in the area.
Is there a good software out there for this?

Thanks.

Replies continue below

Recommended for you

RE: Curtain Wall Design

jike

(Structural)

20 Mar 15 23:59

There is a definite need for engineers to design light gage framing. Our office typically would design projects with only a few light gage elements but if it was a large job we would put it under the responsibility of the contractor. Since I retired over a year ago, I cannot remember the names of software. You also need to develop some standard details.

Good Luck!

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

21 Mar 15 02:00

thank you Jike. What about the aluminum curtain wall/storefront system?

RE: Curtain Wall Design

Ron

(Structural)

21 Mar 15 03:39

kodstruct...most any good FEA software will do. There are some dedicated software packages for light gage design (Check with Dietrich.....they supply light gage framing materials and I believe they have software as well.). If there will be aluminum and glass involved (storefront/curtain wall), you'll need Window Glass Design 5 for all the calcs required to comply with ASTM E for the glass.

I have used RISA 3D for light gage framing analysis and design. I use it for lots of other stuff as well.

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

21 Mar 15 13:07

Thanks Ron... I use SteelSmart for metal stud or light gauge curtain wall design.
However I am looking for a software for aluminum curtain wall and storefront system, capable of designing mullions, and coming up with shop drawings.

RE: Curtain Wall Design

Ron

(Structural)

21 Mar 15 13:16

Check with Kawneer or YKK...they can tell you packages you can use. Be careful of dedicated package software...they are usually limited and proprietary.

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

21 Mar 15 14:54

Fantastic Ron.. Thanks.

RE: Curtain Wall Design

glass99

(Structural)

22 Mar 15 02:09

Curtain wall structural engineering is a whole specialty. The basic calculations are conventional beam theory, but there is a bunch of nitty gritty bits and pieces you have to learn. Fasteners are a big one (TEKS Screws, stainless bolts, machine screws, etc. You finish up with a lot of weird plastics. There is the glass. You need to get familiar with the Aluminum Design Manual. Custom extrusions can be a bit tricky with buckling.

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

22 Mar 15 03:27

@ glass99,

Do you gave any suggestion for any software out there?
You know how it works; once you do do couple designs with the right manual you get it. I would like to start my practice in specialty structural engineering like connection design, light gauge curtain wall design, certified welder inspector and storefront design. There is a huge market because many fumes don't design those things including the firm I am currently working at.

What I see so far, the revenues is more than typical structural engineering design.

Thanks.

RE: Curtain Wall Design

glass99

(Structural)

23 Mar 15 15:58

kostruct: If you are looking for software that automates a lot of the checks involved in curtain wall design, there is not one that I know of. I use Strand7 (FEA), Window Glass Design (glass structural), DrBeam (1d beams), ACAD, Rhino, SolidWorks, Hilti Profis. A lot of people like MEPLA for glass, though I don't use it. SAP has automated aluminum design features which I have heard of some people using. I will caveat this by saying aluminum extrusion related work is less than 5% of what I do. I am more of a structural glass guy.

Curtain wall design can be a good business, or it can be terrible.

RE: Curtain Wall Design

RFreund

(Structural)

23 Mar 15 17:39

Quote (glass99)

Curtain wall design can be a good business, or it can be terrible.

Could you elaborate?

Could you elaborate?

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

glass99

(Structural)

23 Mar 15 21:44

I know facade consultants that drive Porsches and others who can barely afford gas for their '98 Camry. There is huge variation in fees for similar work, and it revolves around the attitude of the consultant. Client side and contractor side have pretty different schtick's. Generally client side is better, but not always.

The two things that make you valuable are the perception that you are either a rock star who's gonna make it awesome, or a Guardian of the Clients Rights and Specification Cop. Straight ahead calcs are kind of a commodity, but even there there are ways to do alright I guess.

To do well as a Specification Cop, you need gravitas, business sense, and an army of inspectors. To do well as a rock star designer, you need good ideas and swagger. To do well as a calc machine, you want to be as high in the analysis cleverness food chain as you can, and be efficient.

RE: Curtain Wall Design

RFreund

(Structural)

24 Mar 15 10:31

Thanks Glass!

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

RFreund

(Structural)

24 Mar 15 10:45

I have now seen a few different curtain wall submitals and it is interesting how different they are. One basically copies in the manufactures tables, says spacing less than max spacing shown in the table; does a quick deflection check; then shows the capacity of a concrete mechanical anchor, then done. The second goes through and computes the section properties of the aluminum extrusion, get the load on the extrusion, checks the section. Then checks the metal fasteners for mullion to mullion connection. Also checks bending of the fasteners (seems a bit conservative given the geometry, but it's nice to see) and also checks anchors. The third does the same as the second but also checks drift and thermal expansion/contraction. They all seem to have a note which says they are not responsible for dissimilar metal contact.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

RFreund

(Structural)

24 Mar 15 19:19

Do you typically check the connection of horizontal to vertical mullion? It seems that you should. Do you typically get the fastener information from the manufacturer or do they provide some sort of maximum reaction?

For mullions which are comprised of two channel shaped members which "snap" together, do you typically treat these as individual channels or can they be treated a box? Maybe I am mis-understanding and these are mechanically fastened together...

How do you typically determine the design property values? Typically all I see in the manufacture info is moment of inertia, and section modulus. How do you determine warping constant, etc.? Are these supplied upon request or do you calculate them yourself?

Thanks!!

While on the subject a couple questions for any curtain wall designers:Do you typically check the connection of horizontal to vertical mullion? It seems that you should. Do you typically get the fastener information from the manufacturer or do they provide some sort of maximum reaction?For mullions which are comprised of two channel shaped members which "snap" together, do you typically treat these as individual channels or can they be treated a box? Maybe I am mis-understanding and these are mechanically fastened together...How do you typically determine the design property values? Typically all I see in the manufacture info is moment of inertia, and section modulus. How do you determine warping constant, etc.? Are these supplied upon request or do you calculate them yourself?Thanks!!

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

24 Mar 15 19:37

Rfreund,

Great questions!!!

I am currently looking for ways to get the properties from the manufacturers.
I think they should have them upon request.

RE: Curtain Wall Design

glass99

(Structural)

24 Mar 15 19:48

If its an off the shelf system like Kawneer, they usually have all the relevant section properties figured out, and they are usually quoted in their manual. But a better way is to use their load charts because it gets you away from having to worry about all the Aluminum compressive strength formulas. You technically should check all the fasteners, including the horizontal mullions.

If its a custom extrusion, you need to check everything! Calculate your own section properties and have at it. Snap on caps are usually not rigidly enough attached to the other components to be composite. Buckling can be complicated.

RE: Curtain Wall Design

RFreund

(Structural)

24 Mar 15 21:21

It is interesting as I'm looking into this further... It seems that most of these calculations use the Aluminum design manual which as far as i can tell doesn't require "J" (torsional constant) or "C.w" (torsional warping constant) when finding allowable stresses for basically all configurations except angles. Conveniently enough it seems like the manufactures, don't have J and/or C.w values. The and ADM uses both for lateral torsional buckling. Unfortunately I'm not an ADM expert so maybe I'm missing something here... It reminds me of how the AISC 9th edition worked vs how the current versions work. It's accounted for, just differently. Unfortunately I'm not old enough to know the 9th edition very well. Maybe someone else can chime in on this?
However it does seem that the manufactures have pretty detailed autocad drawings. I suppose you could use autocad to get "J" but I don't think it will calc "C.w". I suppose you could/should use some other software.

Thanks for the comments Glass!It is interesting as I'm looking into this further... It seems that most of these calculations use the Aluminum design manual which as far as i can tell doesn't require "J" (torsional constant) or "C.w" (torsional warping constant) when finding allowable stresses for basically all configurations except angles. Conveniently enough it seems like the manufactures, don't have J and/or C.w values. The and ADM uses both for lateral torsional buckling. Unfortunately I'm not an ADM expert so maybe I'm missing something here... It reminds me of how the AISC 9th edition worked vs how the current versions work. It's accounted for, just differently. Unfortunately I'm not old enough to know the 9th edition very well. Maybe someone else can chime in on this?However it does seem that the manufactures have pretty detailed autocad drawings. I suppose you could use autocad to get "J" but I don't think it will calc "C.w". I suppose you could/should use some other software.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

RFreund

(Structural)

24 Mar 15 21:22

Also, fyi regarding the design charts... I asked if these charts accounted for the horizontal to vertical mullion connection. They told me that they did not and the fasteners should be checked. I am waiting for more fastener info though.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

RFreund

(Structural)

25 Mar 15 14:58

Quick edit - You do need "J" for tubular sections but not channels. Although these typically aren't actually tubular. The section property calcs and allowable stresses gets a bit intense.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

RFreund

(Structural)

26 Mar 15 13:29

I'm still trying to get a feel for what is industry standard...
I've contacted the manufacturer used for this project (a well known manufacture may have even been mentioned previously) and so far the information I'm trying to get seems to be difficult to get a hold of. Part of the problem seems to be that the shapes are proprietary so they don't want to give you the full geometry of the section. When asking for the section properties, they can give you S and I and c (section modulus, moment of inertia and distance from N/A to extreme fiber) for the shapes but they don't provide (atleast not commonly) J and C.w values. I also politely asked about talking with thier engineer and was told that is basically impossible (not saying that the people I was speaking with weren't very helpful, they were).
It seems as though if you use the (allowable stress method) of Aluminum Design Manual (ADM) you only need J. From talking with the manufacture they seem to calculate J for tube and Channel section just using basic approximate formulas ignoring the 'kinks' in the shape and using an average thickness. I kinda feel like I'm trying to uncover some secret society.

So below is where things are at and I'm curious if anyone can say hey your overdoing it or you're on the right track.

1. Checking mullions: First check the tables provided by the manufacture. To me these are a bit misleading because they don't really determine where the horizontal mullions are applying point loads, however maybe they are conservative. So you could check your height and spacing and if you are withing the limits then you're good. You still however may need to check your horizontal mullion for lateral load as these may not be in the charts. So it seems c, I and S values are provided somewhat readily. So you can check deflection, but now what about strength. Well you you would need J and if using ADM you many need C.w. Now the question is what is the standard level of analysis used. I see a number of ways this could go - (1) The manufacture provides detailed geometry and we calculate the section properties. As noted previously I think they are hesitant to do this given the proprietary shape. (2) The manufacture gives you all the required values (check out ADM illustrated examples curtain wall and you will see there are many variables). Also my experience thus far has been like pulling teeth. (3) You estimate the the sectional properties neglecting the kinds/bends. This currently seems like it is done. (4) You are within the range of the charts and it is likely strength (at least LTB) is not a concern. Check other limit states (i.e. local buckling, section strength). Maybe use this in combination with option (3).

2. Checking fasteners - I was told that the charts do not consider fastener strength. Therefore the screw/fastener properties need to be obtained from the MFG. Or the the allowable loads. This has actually been a somewhat difficult task as well however I believe I know have this information. It would be nice if they provided an allowable load as this again is a long calculation (Although I refer the reader to AAMA TIR A9 for info.

3. Anchoring to substrate - this seems to be the most straight forward as I get to select the anchor.

4. As Glass had mentioned think long and hard about your fee and willingness to get into curtain wall design. I haven't even started on some of the other considerations that other submittals that I reviewed seem to have overlooked or discluded.

Any comments are appreciated. Thanks!

Digging deeper...I'm still trying to get a feel for what is industry standard...I've contacted the manufacturer used for this project (a well known manufacture may have even been mentioned previously) and so far the information I'm trying to get seems to be difficult to get a hold of. Part of the problem seems to be that the shapes are proprietary so they don't want to give you the full geometry of the section. When asking for the section properties, they can give you S and I and c (section modulus, moment of inertia and distance from N/A to extreme fiber) for the shapes but they don't provide (atleast not commonly) J and C.w values. I also politely asked about talking with thier engineer and was told that is basically impossible (not saying that the people I was speaking with weren't very helpful, they were).It seems as though if you use the (allowable stress method) of Aluminum Design Manual (ADM) you only need J. From talking with the manufacture they seem to calculate J for tube and Channel section just using basic approximate formulas ignoring the 'kinks' in the shape and using an average thickness. I kinda feel like I'm trying to uncover some secret society.So below is where things are at and I'm curious if anyone can say hey your overdoing it or you're on the right track.1. Checking mullions: First check the tables provided by the manufacture. To me these are a bit misleading because they don't really determine where the horizontal mullions are applying point loads, however maybe they are conservative. So you could check your height and spacing and if you are withing the limits then you're good. You still however may need to check your horizontal mullion for lateral load as these may not be in the charts. So it seems c, I and S values are provided somewhat readily. So you can check deflection, but now what about strength. Well you you would need J and if using ADM you many need C.w. Now the question is what is the standard level of analysis used. I see a number of ways this could go - (1) The manufacture provides detailed geometry and we calculate the section properties. As noted previously I think they are hesitant to do this given the proprietary shape. (2) The manufacture gives you all the required values (check out ADM illustrated examples curtain wall and you will see there are many variables). Also my experience thus far has been like pulling teeth. (3) You estimate the the sectional properties neglecting the kinds/bends. This currently seems like it is done. (4) You are within the range of the charts and it is likely strength (at least LTB) is not a concern. Check other limit states (i.e. local buckling, section strength). Maybe use this in combination with option (3).2. Checking fasteners - I was told that the charts do not consider fastener strength. Therefore the screw/fastener properties need to be obtained from the MFG. Or the the allowable loads. This has actually been a somewhat difficult task as well however I believe I know have this information. It would be nice if they provided an allowable load as this again is a long calculation (Although I refer the reader to AAMA TIR A9 for info.3. Anchoring to substrate - this seems to be the most straight forward as I get to select the anchor.4. As Glass had mentioned think long and hard about your fee and willingness to get into curtain wall design. I haven't even started on some of the other considerations that other submittals that I reviewed seem to have overlooked or discluded.Any comments are appreciated. Thanks!

EIT
www.HowToEngineer.com

With competitive price and timely delivery, Zhuzao sincerely hope to be your supplier and partner.

Additional reading:
How do Aluminium Mesh Ceilings enhance interiors?

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

26 Mar 15 14:17

@RFreund,

Thanks for the information.

I got a signed proposal this morning for my first project and I am in the same boat as you.
The specs from the Architect calls for Kawneer product.
I went to their webiste for information. However, I don't think they have all the shape they use to manufacture their curtain wall system. I am to use the SS system and they only have few members with I & S values in their wind load chart section.

@RFreund, do you have a technical catalog or CAD file of all their shapes? You are right about the approach you described in your previous, at least it makes sense to me.

The design process itself is straightforward if we have something to work with especially, the Architect (Specs) says NO substitution. So I have to use Kawneer.


I will call Kawneer to see if theyc an help.

Thanks.

RE: Curtain Wall Design

RFreund

(Structural)

26 Mar 15 15:52
I have no such cad file but you can download their details online. These have the shapes but I'm not sure if they are drawn exactly to scale. Also try to find their estimating guide which relates sizes to part numbers.

If you some how get to their guarded engineers. Let me know what they have to say, I'd like to pose these questions to them and try to understand their tables. Also for their clearwall system they actually tape a component to the glass which attaches to a toggle.

That will make 2 of us.I have no such cad file but you can download their details online. These have the shapes but I'm not sure if they are drawn exactly to scale. Also try to find their estimating guide which relates sizes to part numbers.If you some how get to their guarded engineers. Let me know what they have to say, I'd like to pose these questions to them and try to understand their tables. Also for their clearwall system they actually tape a component to the glass which attaches to a toggle.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

Ingenuity

(Structural)

26 Mar 15 16:04

Maybe it is indeed a 'secret society', outside the USA too.

When I had to check a aluminium section from an Australian manufacturer (Capral) for a project I had to obtain a company issued login to their online site to get the info. Once logged in, I had access to a lot of data, including CAD drawings of sections etc.

Good luck.

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

26 Mar 15 16:14

Then it's serious.
if they manufacture something and want Architects to specify them then they should have catalogs where engineers will get the data just like Verco, Vulcraft, etc.....
At the end of the day, the products will be shipped from their warehouses, so i don't see the issue.

Is it like that? Seriously... How curtain wall engineers do? I have 3 weeks to complete the design & shop drawings.
Any help?

Thanks.

RE: Curtain Wall Design

glass99

(Structural)

26 Mar 15 16:14

http://www.kawneer.com/kawneer/north_america/en/ca...

Generally speaking if you are doing standard Kawneer with no funny business, you don't need their CAD files. Lateral buckling is not really a thing with tubular sections. However if you feel you need it, CAD sections are available on their website.

RE: Curtain Wall Design

glass99

(Structural)

26 Mar 15 16:28

kostruct: three whole weeks? Welcome to the glazer's schedule. When you work for an owner or arch your schedule is measured in years, when you work for a glazer its weeks. Its a pretty jarring difference. If you do the same thing in the middle east its measured in days. Spoke to an engineer in Dubai a couple of years back who designed a 100m span roof with complex geometry, custom milled steel nodes and a funky islamic pattern for the structural members in two weeks. It was insane.

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

26 Mar 15 16:53

@Glass,

Great info. thanks.....
Yes 3 weeks, lol...I thought I could access the manufacturer catalog when I wrote the proposal.
I clicked on the link you sent and they only have few types (, , vertical mullions). I hope these types work with the wind my design.

Thanks a bunch.

RE: Curtain Wall Design

RFreund

(Structural)

26 Mar 15 17:45

I found the cad files as well, however it seems odd that they would have a to scale cad file with exact dimensions but not distribute a dimensioned drawing. I did a Massprop in autocad and it appears to match the I values published in the wind load charts so maybe that is accurate.

So it seems like if you're layout is fairly typical there isn't too much to worry about and could perhaps use simplified geometric properties. But then that begs the question, what if it's not such a simple case.
It would be nice just to see a detailed strength design calc from the manufacture similar to in the ADM for the curtain wall example. Then you'd have all the values. I know this is a bit much and would take all the fun out of it. But I'm assuming they must have went through this procedure at some point.

Yeah we the have same time frame.I found the cad files as well, however it seems odd that they would have a to scale cad file with exact dimensions but not distribute a dimensioned drawing. I did a Massprop in autocad and it appears to match the I values published in the wind load charts so maybe that is accurate.So it seems like if you're layout is fairly typical there isn't too much to worry about and could perhaps use simplified geometric properties. But then that begs the question, what if it's not such a simple case.It would be nice just to see a detailed strength design calc from the manufacture similar to in the ADM for the curtain wall example. Then you'd have all the values. I know this is a bit much and would take all the fun out of it. But I'm assuming they must have went through this procedure at some point.

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

kodstruct

(Structural)

(OP)

26 Mar 15 18:27

RFreund,

That's right....I just did the massprop as well and it matches.
My curtain walls are 13' so i hope these sizes work. If it doesn't I will add aluminum C channel or something for reinforcement.

RE: Curtain Wall Design

RFreund

(Structural)

9 Apr 15 20:19

Are sills typically designed to carry the dead load (and lateral load) of the glass between vertical mullions even if there is substrate below (Similar to intermediate horizontal mullions)? Usually there is gap between the bottom sill and the substrate but you could add blocking in which case you wouldn't need to span the sill between the vertical mullions. However unless the substrate is foundation the member is probably not designed to support glass vertically. So I suppose any situation other than the blocking between foundation and sill the sill would need to span between vertical mullions, no?

Is the only connection to the substrate then typically at the T&F anchors at the vertical mullions or is the sill (or head for that matter) ever fastened to the substrate as well? I would think not, as you would want to allow for differential movement and the only way this is accomplished with through the T&F anchors, right?

Thanks!

Another question here...Are sills typically designed to carry the dead load (and lateral load) of the glass between vertical mullions even if there is substrate below (Similar to intermediate horizontal mullions)? Usually there is gap between the bottom sill and the substrate but you could add blocking in which case you wouldn't need to span the sill between the vertical mullions. However unless the substrate is foundation the member is probably not designed to support glass vertically. So I suppose any situation other than the blocking between foundation and sill the sill would need to span between vertical mullions, no?Is the only connection to the substrate then typically at the T&F anchors at the vertical mullions or is the sill (or head for that matter) ever fastened to the substrate as well? I would think not, as you would want to allow for differential movement and the only way this is accomplished with through the T&F anchors, right?Thanks!

EIT
www.HowToEngineer.com

RE: Curtain Wall Design

Thinktanck

(Structural)

16 Jun 15 16:59

kodstruct...

I'm new to this forum. I actually joined after I read this CW thread. I'm an Engineering Team Lead for a company that designs custom unitized curtain wall. Prior to this, I was Engineering Manager for a similar company that only used stick systems (Kawneer, Efco, Tubelite, etc...) I've also done contract work for glazing and ACM panel companies. You are correct in your assessment of the industry. It is a niche. A lot of our interns or new hires have degrees in Mechanical or Structural Engineering, but there is a lot of intense facade specific training that we give them. I'd like to know how you are doing in your "infiltration" into the CW world. lol. Maybe I can help.

Thanks

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News

Above: Aaron Blom presenting during GlassBuild America

Editor&#;s Note: The following is based on the education session &#;Curtain Walls | Design Considerations, Tolerances and Testing,&#; presented by Blom at GlassBuild America, held Oct. 18-20, , in Las Vegas. Find more news and coverage from the show.

In its basic form, a curtain wall system consists of insulating glass and extruded aluminum framing either installed piece by piece in the field (stock lengths), or installed using pre-assembled, pre-glazed framing and glass panels (unitized). Hybrid versions include various system options and fabrication and installation techniques that can be used to achieve specific design aesthetics as well as maximize fabrication and installation efficiency.

Regardless of the installation methods used, curtain wall systems must address five primary design considerations: structural integrity, movement capability, weathertightness, energy efficiency and sound control.

Structural integrity

As with all types of fenestration, wind load is an important structural consideration for curtain wall systems. The more the frame deflects due to the design wind load, the more stress is placed on the assembly and the greater the likelihood of system failure and/or glass breakage. The engineering calculation used to determine maximum vertical framing deflection is L/175 for spans up to 13 feet 6 inches and L/240 + ¼-inch for spans that are greater, where L is the vertical span length. Other structural performance considerations include live load, dead load, seismic and inter-story drift.

Provision for movement

There are multiple factors to consider when designing a curtain wall system to accommodate expected movement, including thermal expansion and contraction, movement due to wind load and gravitational forces, and movement caused by deformation or displacement of the building. Movement must be accommodated to limit the stress on the glass, framing and anchors, and without excessively reducing the frame&#;s &#;bite&#; or capture of the glass.

Weathertightness

Weathertightness means protection against both air and water leakage.

Water penetration. There are two methods for preventing water leakage through a curtain wall system. One is the &#;internal drainage&#; system utilizing weep holes in the pressure plate and face cap. The other is achieved through "pressure equalization" of the system. Basically, a pressure-equalized design ensures there is not a significant negative pressure pulling water into the system from the exterior.

Air infiltration. For obvious reasons, excessive air infiltration is less critical than water penetration but can compromise the energy efficiency of the building envelope. Industry standards limit air infiltration to 0.3 liters per second air leakage per square meter of fixed wall area (0.06 cubic feet per minute per square foot of area) when tested at an air pressure difference of 1.57 pound-force per square foot.

Energy efficiency

Curtain wall systems must meet an overall maximum thermal transmittance or U-Factor (W/m2&#;K or Btu/hr&#;ft2&#;°F) stipulated by applicable codes based on project location and other project-specific thermal performance requirements. Improved thermal performance can be accomplished in multiple ways, including using thermally broken framing materials, using high-performance insulating glass and adequately insulating large spandrel areas.

Sound control

Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC) are the standard methods for rating sound attenuation of glass and window systems. Using laminated insulating glass, using insulating glass with an increased airspace and minimizing air infiltration will generally improve sound transmission&#;of particular concern near airports and in metropolitan areas.

Performance and testing requirements

Due to the wide range of forces that act upon a building in a particular location, physical testing for air infiltration, water penetration and structural performance (including frame deflection limits) is often the only reliable means of verifying performance in field conditions. This testing may be conducted on stand-alone mock-ups or on completed installations, also called in-place mock-ups.

For more Curtain Wall Engineeringinformation, please contact us. We will provide professional answers.