# DALC > Estimates ductwork air leakage and determines pass/fail for duct air leakage tests. (iPhone/iPad app by SHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC..) - Source: https://appshunter.io/ios/app/dalc/id427624076 (this page in markdown: same URL + `.md`) - Developer: [SHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC.](https://appshunter.io/developer/427624079) - Category: Business - Price: Free - Rating: 2.20/5 from 26 App Store ratings · 26 written reviews indexed - Age rating: 4+ - Requires: iOS 6.0 · 10 MB - Languages: American English, German (Germany) - Released: 2011-03-31 - Data updated: 2026-06-10 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/dalc/id427624076/reviews.md ## What is DALC? This simple to use but effective application is provided by the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA). This tool allows engineers, architects, designers, and contractors to easily and accurately estimate the leakage of air from ductwork. It also allows a quick and easy way to determine the pass/fail mark for properly specified Duct Air Leakage Tests (DALT). Users can combine multiple sections of ductwork that vary by size and shape to calculate a total allowable leakage. The application uses the method outlined in SMACNA’s HVAC Air Duct Leakage Manual, and provides suggested leakage classes from SMACNA’s latest edition of the manual. The method used is compliant with ASHRAE 90.1, IECC, IGCC Version 2, IMC and the UMC. ## Key features - Estimate ductwork air leakage - Determine DALT pass/fail - Combine multiple duct sections - Calculate total allowable leakage - Provides suggested leakage classes - Compliant with industry standards ## Recent user reviews (10 of 26) All indexed reviews: https://appshunter.io/ios/app/dalc/id427624076/reviews.md ### 2/5 — iPad operation *2025-08-08, version 2.1* The app does not open on an iPad. ### 1/5 — Needs update *2025-05-07, version 2.1* App crashes, can’t use ### 1/5 — Mandatory crash *2025-03-26* You are not allowed to go past the first screen without putting your email address in. However, when you go to type in your email address, the app crashes every time. Useless. ### 1/5 — Keeps crashing *2025-03-10, version 2.1* App keeps crashing - cannot open it and use it. I’ve tried to download it a couple times and it still doesn’t work. ### 1/5 — Crashes *2024-05-29, version 2.1* No longer works on IPhone. Just crashes after a few letters input in name. Reloaded and still the same. ### 1/5 — No longer works *2023-05-24, version 2.1* Crashes immediately ### 2/5 — Needs updated rash on start *2022-08-24, version 2.1* Can you guys please update this app for the latest iPad os all it does rite now is instant crash on start on iPadOs 15.6.1 ### 1/5 — App doesn’t work *2022-04-25, version 2.1* Have to use website app don’t work ### 3/5 — Used to work *2021-11-11, version 2.1* This app no longer works with my iPhone 12. Help because I like the app! ### 4/5 — Problems *2021-06-29, version 2.1* Since I updated my iPhone to iOS 14.6 this app is not working for me anymore. And I used it all the time. Is there a update for me so I can continue using this app. ## Frequently asked questions about DALC ### What does the DALC app do? This application helps engineers, architects, designers, and contractors accurately estimate the leakage of air from ductwork. It also allows for a quick determination of the pass/fail mark for properly specified Duct Air Leakage Tests (DALT). ### How does the app calculate leakage? Users can combine multiple sections of ductwork that vary by size and shape to calculate a total allowable leakage. The application uses the method outlined in SMACNA’s HVAC Air Duct Leakage Manual and provides suggested leakage classes from the latest edition. ### Is this app free to use? Yes, based on the provided information, the application is offered for free. ### What industry standards does this app comply with? The method used by the application is compliant with ASHRAE 90.1, IECC, IGCC Version 2, IMC, and the UMC. ### Who would benefit from using this app? This app is designed for professionals in the sheet metal and air conditioning industry, including engineers, architects, designers, and contractors who need to accurately assess ductwork air leakage and ensure compliance with testing standards. ## Version history (last 4 releases) ### 2.1 — 2014-11-24 This app has been updated by Apple to display the Apple Watch app icon. Key Changes: • Calculations can now be produced in English and Metric units • The app produces final reports in pdf and csv (excel) formats • Project information and specifications can now be saved and edited • There is a new “Custom” shape section that allows the user to input dimensions for different duct shapes. • “Surface Area” tab can now be used in place of inputting specific dimensions (width, length, etc.) for duct ### 2.0 — 2014-11-12 SMACNA’s DUCT AIR LEAKAGE Calculator (DALC) Version 2.0 offers several new features and enhances previous features from the original DALC. Key Changes: • Calculations can now be produced in English and Metric units • The app produces final reports in pdf and csv (excel) formats • Project information and specifications can now be saved and edited • There is a new “Custom” shape section that allows the user to input dimensions for different duct shapes. • “Surface Area” tab can now be used in place of inputting specific dimensions (width, length, etc.) for duct ### 1.1 — 2011-04-12 iPhone home button now resets application ### 1.0 — 2011-03-31 No release notes. ## Apps similar to DALC | App | Rating | Price | Category | | --- | --- | --- | --- | | [AeroBT](https://appshunter.io/ios/app/aerobt/id1466854985) | 5.0 (3) | Free | Business | | [Building Start](https://appshunter.io/ios/app/building-start/id442975774) | 3.4 (8) | Free | Business | | [ASHRAE DFDB Lite](https://appshunter.io/ios/app/ashrae-dfdb-lite/id6475053772) | — | Free | Business | | [Trimble® FabShop Mobile Pro](https://appshunter.io/ios/app/trimble-fabshop-mobile-pro/id1244844695) | — | Free | Business | | [EB-Link](https://appshunter.io/ios/app/eb-link/id1254019997) | 5.0 (7) | Free | Business | ## More apps by SHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC. - [SMACNA HVAC DCS](https://appshunter.io/ios/app/smacna-hvac-dcs/id716751022) - [SMACNA Event](https://appshunter.io/ios/app/smacna-event/id1643514408) - [SMACNA Events](https://appshunter.io/ios/app/smacna-events/id6670240458) - [SMACNA Duct-U-Lator](https://appshunter.io/ios/app/smacna-duct-u-lator/id6702024229) All apps by SHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC.: https://appshunter.io/developer/427624079 ## Related topics [ductemissiontool](https://appshunter.io/ios/topics/ductemissiontool) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*