# Duct Sensor Assistant vs Elvaco OTC

The clearest difference is update cadence: Elvaco OTC at monthly against Duct Sensor Assistant's every 6 months. Duct Sensor Assistant's advantage is iOS requirement (12.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Duct Sensor Assistant ships an update every 6 months, Elvaco OTC monthly. The most recent releases landed on September 16, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Duct Sensor Assistant | Elvaco OTC |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Monthly** |
| Size | 31 MB | 14 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [BELIMO Automation AG](https://appshunter.io/developer/1149281298) | [Elvaco AB](https://appshunter.io/developer/1590157446) |

## What reviewers say

### Duct Sensor Assistant

[App page](https://appshunter.io/ios/app/duct-sensor-assistant/id1559862597)

**Features:** macOS Compatibility

**In-app purchases:** none


### Elvaco OTC

[App page](https://appshunter.io/ios/app/elvaco-otc/id1590157384)

**In-app purchases:** none


## Frequently asked questions

### Is Duct Sensor Assistant free?

Duct Sensor Assistant is free to download, with no in-app purchases.

### Is Elvaco OTC free?

Elvaco OTC is free to download, with no in-app purchases.

### Do Duct Sensor Assistant or Elvaco OTC have ads?

Neither Duct Sensor Assistant nor Elvaco OTC shows ads.

### Which is updated more often, Duct Sensor Assistant or Elvaco OTC?

Duct Sensor Assistant ships an update every 6 months, and Elvaco OTC monthly. Most recently, Duct Sensor Assistant was updated on September 16, 2026 and Elvaco OTC on September 23, 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.*