# GB Gas Ventilation Calculator — BS5440 Calculator > Gas appliance ventilation requirements calculator for professionals. (iPhone/iPad app by GB-GAS.CO.UK.) - Source: https://appshunter.io/ios/app/gb-gas-ventilation-calculator/id426220160 (this page in markdown: same URL + `.md`) - Developer: [GB-GAS.CO.UK](https://appshunter.io/developer/425897007) - Category: Business, Utilities - Price: $3.99 - Age rating: 4+ - Requires: iOS 26.0 · 3 MB - Released: 2011-03-26 - Data updated: 2026-09-09 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/gb-gas-ventilation-calculator/id426220160/reviews.md ## What is GB Gas Ventilation Calculator? A Gas Ventilation calculator for working out ventilation requirements for gas appliances. Open flued, Room sealed, Flueless appliances. This gives you the option of working out ventilation when more than one appliance is fitted in a room. For existing and new ventilators you can calculate the free air area of the vent to work out if its suitable for the appliance(s) it is feeding. No more formulas and calculations to remember, read the heat input from the appliance data badge and press calculate. ## Key features - Ventilation calculations for gas appliances - Supports open flued, room sealed, and flueless types - Calculates for multiple appliances in one room - Determines free air area of vents - Reads appliance data directly ## Recent user reviews (4 of 4) All indexed reviews: https://appshunter.io/ios/app/gb-gas-ventilation-calculator/id426220160/reviews.md ### 2/5 — Multiple rooms *2016-12-12* What's going on with multiple rooms it won't do anything I cannot enter anything. This was the sole purpose for me buying this app and it does Nothing ????? I have been robbed ### 1/5 — GB ventilation calculator *2012-10-17* Yes it will not return from multiple room screen, I'm not very impressed not with the money, can I have mine back please ### 1/5 — Rubbish *2012-05-27* Did not work when I bought it Still does not work after First update ### 1/5 — Not that good! *2011-06-07* I'm abit confused the app won't return from multiple room screen?? And won't let me input anything! Am I missing something? ## Frequently asked questions about GB Gas Ventilation Calculator ### What is the price of GB Gas Ventilation Calculator? GB Gas Ventilation Calculator is a paid app priced at $3.99. This one-time purchase grants you access to all its features without recurring fees. ### Does GB Gas Ventilation Calculator have ads? No, GB Gas Ventilation Calculator is ad-free. You can use the application without any interruptions from advertisements. ### What devices is GB Gas Ventilation Calculator compatible with? GB Gas Ventilation Calculator is available for iPhone, iPad, and iPod. It is designed to run on Apple's mobile operating systems. ### How often is GB Gas Ventilation Calculator updated? The latest version of GB Gas Ventilation Calculator is version 5, which was last updated on July 24, 2020. Updates typically address bug fixes and feature enhancements. ### What is the age rating for GB Gas Ventilation Calculator? GB Gas Ventilation Calculator has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content. ### Can GB Gas Ventilation Calculator calculate ventilation for multiple gas appliances in one room? Yes, GB Gas Ventilation Calculator provides the option to calculate ventilation requirements when more than one appliance is fitted in a room. This ensures accurate calculations for complex installations. ### How does GB Gas Ventilation Calculator simplify calculations? GB Gas Ventilation Calculator eliminates the need for manual formulas and calculations. You can simply read the heat input from the appliance data badge and press calculate. ### What types of gas appliances does GB Gas Ventilation Calculator support? GB Gas Ventilation Calculator supports open flued, room sealed, and flueless gas appliances. It also allows you to calculate the free air area of existing and new ventilators. ## Version history (last 5 releases) ### 6 — 2026-08-15 Updates to the user interface, ventilation requirements have not changed. ### 5 — 2020-07-24 IOS updates ### 4 — 2017-08-03 IOS updates ### 3.1 — 2014-01-16 minor fix for Ipad ### 3 — 2012-09-26 updates to match with iOS 6 ## Apps similar to GB Gas Ventilation Calculator | App | Rating | Price | Category | | --- | --- | --- | --- | | [Logos HD for Adobe InDesign® - Editable Royalty-Free Templates](https://appshunter.io/ios/app/logos-hd-for-adobe-indesign-editable-royalty-free-templates/id441449851) | 1.0 (2) | Free | Business | | [Gas App Uk](https://appshunter.io/ios/app/gas-app-uk/id1033168436) | 3.0 (2) | Free | Business | | [Asset Management System](https://appshunter.io/ios/app/asset-management-system/id1467963969) | — | Free | Business | | [MyJobDone Partner](https://appshunter.io/ios/app/myjobdone-partner/id1613158511) | — | Free | Business | | [Nimbus 9 - Commissioning Tool](https://appshunter.io/ios/app/nimbus-9-commissioning-tool/id1433809710) | — | Free | Business | | [Viessmann Warranty](https://appshunter.io/ios/app/viessmann-warranty/id1387870221) | — | Free | Business | ## More apps by GB-GAS.CO.UK - [GB Gas Heat Input Calculator](https://appshunter.io/ios/app/gb-gas-heat-input-calculator/id426032737) - [GB Gas Purging Calculator](https://appshunter.io/ios/app/gb-gas-purging-calculator/id426227084) - [GB Gas Pipe Sizing Calculator](https://appshunter.io/ios/app/gb-gas-pipe-sizing-calculator/id427457719) - [GB Gas Tightness Testing](https://appshunter.io/ios/app/gb-gas-tightness-testing/id428846431) - [GB Gas Tightness NG + LPG](https://appshunter.io/ios/app/gb-gas-tightness-ng-plus-lpg/id430236121) All apps by GB-GAS.CO.UK: https://appshunter.io/developer/425897007 --- *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 2026-09-09.*