# CO2 Risk Calculator vs AirCompare™

The clearest difference is update cadence: AirCompare™ at every 3 months against CO2 Risk Calculator's every 9 months. CO2 Risk Calculator's advantage is iOS requirement (11.0 vs 16.0). 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.

CO2 Risk Calculator ships an update every 9 months, AirCompare™ every 3 months. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | CO2 Risk Calculator | AirCompare™ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (3 ratings)](https://appshunter.io/ios/app/aircompare/id1265636598/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 66.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 3 months** |
| Monetization | — | Free |
| Size | 6 MB | 7 MB |
| Requires iOS | **11.0** | 16.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Logico2 International AB](https://appshunter.io/developer/1208875120) | [Wayne Henderson](https://appshunter.io/developer/1265636597) |

## What reviewers say

### CO2 Risk Calculator

[App page](https://appshunter.io/ios/app/co2-risk-calculator/id1019495878)

**In-app purchases:** none


### AirCompare™

[App page](https://appshunter.io/ios/app/aircompare/id1265636598)

Optimize home energy usage and save money with smart ventilation and thermostat control. This app analyzes indoor and outdoor air quality, local weather, and electricity rates to automatically adjust your HomeKit-enabled devices for optimal comfort and cost savings.

**Highlights:** Ventilation controller, Thermostat controller, Automatic HomeKit device control, Energy consumption reduction, Weather and electricity rate analysis, Customizable rain sensitivity

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CO2 Risk Calculator free?

CO2 Risk Calculator is free to download, with no in-app purchases.

### Is AirCompare™ free?

AirCompare™ is free to download, with no in-app purchases.

### Do CO2 Risk Calculator or AirCompare™ have ads?

Neither CO2 Risk Calculator nor AirCompare™ shows ads.

### Which is updated more often, CO2 Risk Calculator or AirCompare™?

CO2 Risk Calculator ships an update every 9 months, and AirCompare™ every 3 months. Most recently, CO2 Risk Calculator was updated on November 6, 2026 and AirCompare™ on November 2, 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.*