ViGuide vs DuctCalc.Ca
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ViGuide
Streamline the process of commissioning Viessmann boilers with this user-friendly mobile application. It guides trained professionals through each step, ensuring a safe, efficient, and complete installation.
- Streamlined boiler commissioning
- User-friendly mobile interface
- Step-by-step guidance
- Ensures complete and correct steps
- Efficient installation process
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ViGuide - the best way to commission a Viessmann boiler • Please note this app is intended only for trained professionals. If you are not certified to install and commission a Viessmann product, please call your local installer or contact us to help you find a Viessmann partner in your area. • It’s time for a new start We have completely streamlined boiler commissioning and moved the process to a user-friendly mobile app. In a couple of simple steps, ViGuide will safely guide you through the process of commissioning a Viessmann boiler. Even you are new to the Viessmann boiler model, the simplified app allows you to carry out the steps with ease, as efficiently as possible and in less time. The app will guide you step-by-step through the commissioning process and thus ensures that all necessary commissioning steps are carried out completely and in the correct order.
DuctCalc.Ca
This utility app calculates duct dimensions and air velocity using two methods: Equal Friction and Velocity. It supports both round and rectangular ducts, offering precise calculations for HVAC professionals. Offline functionality is available with a subscription.
- Duct sizing calculator
- Equal Friction Method
- Velocity Method
- Round and rectangular duct support
- Offline functionality
- Full air flow range activation
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DuctCalc.Ca is the iOS offline version of the most popular online ductulator app (ductcalc.ca) Enjoy using the app with no internet connection when subscribed! App engineering explanation: ------------------------------ Equal Friction Method: Using a predefined static pressure loss per unit of duct length, DuctCalc.Ca Ductulator App calculates the diameter of round duct and the other dimension of rectangular duct. Based on the calculated dimensions, the air velocity will be calculated for both duct shapes and dimensions. Velocity Method: Using a predefined air velocity, DuctCalc.Ca Ductulator App calculates the diameter of round duct and the other dimension of a rectangular duct. Based on the calculated dimensions, the static pressure loss will be calculated for both duct shapes and dimensions. Note that unlike conventional ductulators, this ductulator will calculate the dimensions of the rectangular duct based on the given velocity and it then calculates the static pressure loss for the rectangular duct based on the given velocity and dimensions. Most old calculators will only use the given velocity to calculate the diameter of the round duct then it calculates the static pressure loss for the round duct and uses that static pressure to calculate the rectangular duct dimensions which is not the case here for more precise velocity output. Colebrook equation is used to solve for Darcy's friction factor and calculates the static pressure loss in the duct until it matches the desired input at defined airflow and absolute roughness of the inner material of the duct touching the moving air. In-App Purchases: ------------------- • With no subscription the app will calculate for an air flow range between (950 and 1100 [cfm]). To activate full air flow functionality. There are four subscription options: one month, three months, six months and one year. • All subscription options will activate the "Full Air Flow Functionality" of the duct sizing app for that specific subscription period. The full air flow range is (1 to 500,000 [CFM] or 1 to 235,974 [L/s] in metric units). • Payment will be charged to iTunes Account at confirmation of purchase. • Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable. Privacy Policy: https://ductcalc.ca/?page=agreement Terms of Service: https://ductcalc.ca/?page=agreement
Screenshots
Verdict
The clearest difference is rating: ViGuide at 4.5 against DuctCalc.Ca's 1.9. ViGuide also leads on in-app purchases (none vs 4) and update cadence (every 5 weeks vs every 4 months). DuctCalc.Ca's advantage is review sentiment (50% vs 41%) and iOS requirement (11.3 vs 16.0). On price, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. DuctCalc.Ca sells 4 one-off in-app purchases. ViGuide asks for nothing beyond the download.
ViGuide holds the better App Store score, 4.5 against 1.9. That said, the two scores are not equally well evidenced: ViGuide has 208 ratings behind it against 20, so its average is the more settled of the two. Written reviews complicate that: 41% of ViGuide's written reviews are positive against 50% of DuctCalc.Ca's, so the app with the better star average is not the one people write more warmly about.
ViGuide ships an update every 5 weeks, DuctCalc.Ca every 4 months. The most recent releases landed on October 26, 2026 and October 17, 2026 respectively.
| Parameter | ViGuide | DuctCalc.Ca |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (208 ratings) — better | 1.9 (20 ratings) |
| Positive reviews | 40.5% of reviews | 50.0% of reviews — better |
| Number of ratings | 208 — better | 20 |
| Update frequency | Every 5 weeks — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 11.3 — better |
| Further details — not scored | ||
| Size | 1.5 GB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | Viessmann IT Service GmbH | Firas Kneifati |
Customer experience
ViGuide
DuctCalc.Ca
In-app purchases
ViGuide
No in-app purchases
DuctCalc.Ca
- One Month Full Air Flow$6.99
- Three Months Full Air Flow$17.99
- Six Months Full Air Flow$29.99
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- One Year Full Air Flow$49.99









