# Sirrus vs Dairy Ventilation

The clearest difference is rating: Dairy Ventilation at 5.0 against Sirrus's 3.5. Dairy Ventilation also leads on in-app purchases (none vs 2) and update cadence (every 2 weeks vs every 2 months). Sirrus's advantage is ratings volume (43 vs 4). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Sirrus sells 2 in-app purchases, starting at $62.00 per month. Dairy Ventilation asks for nothing beyond the download.

Dairy Ventilation holds the better App Store score, 5.0 against 3.5. That said, the two scores are not equally well evidenced: Sirrus has 43 ratings behind it against 4, so its average is the more settled of the two.

Sirrus ships an update every 2 months, Dairy Ventilation every 2 weeks. The most recent releases landed on October 23, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Sirrus | Dairy Ventilation |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.5 (43 ratings)](https://appshunter.io/ios/app/sirrus/id684978309/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/dairy-ventilation/id6767579932/reviews)** |
| Number of ratings | **43** | 4 |
| Positive reviews | 43.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Freemium | **Free** |
| Size | 115 MB | 27 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Telus Ag and Consumer Goods](https://appshunter.io/developer/1746377892) | [University of Wisconsin-Madison Shared Apps](https://appshunter.io/developer/908478605) |

## What reviewers say

### Sirrus

[App page](https://appshunter.io/ios/app/sirrus/id684978309)

This app helps farmers and agronomists manage field data, scout crops, and make informed decisions. It allows for offline data collection, sharing recommendations, and generating reports. Premium features offer advanced editing and product information access.

**Highlights:** Offline field data collection, Crop scouting and observation recording, Create and share recommendations, Generate PDF reports, Soil sampling tools, Export data as shapefile, Hourly rainfall estimates

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sirrus Premium | $62.00 | per month |
| Sirrus Premium | $749.99 | per year |


### Dairy Ventilation

[App page](https://appshunter.io/ios/app/dairy-ventilation/id6767579932)

This tool helps dairy producers make informed decisions about managing heat stress and mechanical ventilation in barns. It calculates key metrics like the Temperature-Humidity Index and fan efficiency, aiding in system design and upgrades.

**Highlights:** Temperature-Humidity Index (THI) calculation with location-based weather, Fan sizing and selection for barns, Assessment of existing ventilation performance, Fan efficiency comparison, Payback period analysis for upgrades

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Sirrus free?

Sirrus is free to download, with in-app purchases available.

### Is Dairy Ventilation free?

Dairy Ventilation is free to download, with no in-app purchases.

### Which has better reviews, Sirrus or Dairy Ventilation?

Dairy Ventilation is rated higher. Sirrus averages 3.5 out of 5 from 43 ratings, while Dairy Ventilation averages 5.0 from 4 ratings.

### Do Sirrus or Dairy Ventilation have ads?

Neither Sirrus nor Dairy Ventilation shows ads.

### Which is updated more often, Sirrus or Dairy Ventilation?

Sirrus ships an update every 2 months, and Dairy Ventilation every 2 weeks. Most recently, Sirrus was updated on October 23, 2026 and Dairy Ventilation on October 14, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*