# Ref Tools vs Duct Sensor Assistant

The clearest difference is update cadence: Ref Tools at every 6 weeks 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.

Ref Tools ships an update every 6 weeks, Duct Sensor Assistant every 6 months. The most recent releases landed on September 19, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Ref Tools | Duct Sensor Assistant |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (52 ratings)](https://appshunter.io/ios/app/ref-tools/id472312541/reviews)** | — |
| Number of ratings | **52** | — |
| Positive reviews | 57.6% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 6 months |
| Monetization | Free | — |
| Size | 98 MB | 31 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Danfoss A/S](https://appshunter.io/developer/423984644) | [BELIMO Automation AG](https://appshunter.io/developer/1149281298) |

## What reviewers say

### Ref Tools

[App page](https://appshunter.io/ios/app/ref-tools/id472312541)

This app provides HVACR technicians with essential tools and information for field service. It includes refrigerant calculators, troubleshooting guides, product finders, and access to spare parts. Listen to educational podcasts to enhance your knowledge on the go.

**Highlights:** Refrigerant Slider for P/T calculations, Solenoid valve coil testing tool, Refrigeration system troubleshooting guide, Product data finder, Spare parts ordering, Low-GWP refrigerant comparison, TXV Superheat optimization, Educational podcasts

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

**In-app purchases:** none


### Duct Sensor Assistant

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

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Ref Tools free?

Ref Tools is free to download, with no in-app purchases.

### Is Duct Sensor Assistant free?

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

### Do Ref Tools or Duct Sensor Assistant have ads?

Neither Ref Tools nor Duct Sensor Assistant shows ads.

### Which is updated more often, Ref Tools or Duct Sensor Assistant?

Ref Tools ships an update every 6 weeks, and Duct Sensor Assistant every 6 months. Most recently, Ref Tools was updated on September 19, 2026 and Duct Sensor Assistant on September 16, 2026.

---

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