# HVAC School vs A2L Certification Test Prep

The clearest difference is in-app purchases: HVAC School at none against A2L Certification Test Prep's 1. HVAC School also leads on ads (none vs shown) and ratings volume (81 vs 3). A2L Certification Test Prep's advantage is update cadence (every 5 days vs monthly) and rating (5.0 vs 4.8). On price and device support there is nothing between them.

Both are free to download. A2L Certification Test Prep sells 1 one-off in-app purchase. HVAC School asks for nothing beyond the download.

A2L Certification Test Prep holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: HVAC School has 81 ratings behind it against 3, so its average is the more settled of the two.

HVAC School ships an update monthly, A2L Certification Test Prep every 5 days. The most recent releases landed on October 4, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | HVAC School | A2L Certification Test Prep |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (81 ratings)](https://appshunter.io/ios/app/hvac-school/id1436085954/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/a2l-certification-test-prep/id6760899340/reviews)** |
| Number of ratings | **81** | 3 |
| Positive reviews | 82.8% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 5 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 30 MB | 47 MB |
| Requires iOS | **13.4** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kalos Services Inc.](https://appshunter.io/developer/1435107751) | [Mike Watson](https://appshunter.io/developer/1848411021) |

## What reviewers say

### HVAC School

[App page](https://appshunter.io/ios/app/hvac-school/id1436085954)

This app serves as a comprehensive resource for HVAC technicians, offering a podcast, tech tip articles, and interactive calculators. It aims to enhance knowledge of HVAC theory, industry updates, and essential mathematics for both current and aspiring professionals.

**Highlights:** HVAC School podcast episodes, Tech tip articles by professionals, Interactive HVAC equation calculators, Industry knowledge and theory, Up-to-date industry information

**Features:** macOS Compatibility

**In-app purchases:** none


### A2L Certification Test Prep

[App page](https://appshunter.io/ios/app/a2l-certification-test-prep/id6760899340)

This professional tool provides accurate refrigerant charging calculations for next-generation gases like R-454B and R-32. It features error-proof charging, a maximum allowable charge calculator, and offline reference materials for HVAC technicians.

**Highlights:** A2L-ready for R-454B and R-32, Error-proof superheat/subcooling calculations, Integrated Max Allowable Charge Calculator, Branded PDF field reports, Offline P/T charts and safety guides, No account or login required

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| A2L SafeCharge Pro | $1.99 | one-time |


## Frequently asked questions

### Is HVAC School free?

HVAC School is free to download, with no in-app purchases.

### Is A2L Certification Test Prep free?

A2L Certification Test Prep is free to download, with in-app purchases available.

### Which has better reviews, HVAC School or A2L Certification Test Prep?

A2L Certification Test Prep is rated higher. HVAC School averages 4.8 out of 5 from 81 ratings, while A2L Certification Test Prep averages 5.0 from 3 ratings.

### Do HVAC School or A2L Certification Test Prep have ads?

A2L Certification Test Prep shows ads; HVAC School does not.

### Which is updated more often, HVAC School or A2L Certification Test Prep?

HVAC School ships an update monthly, and A2L Certification Test Prep every 5 days. Most recently, HVAC School was updated on October 4, 2026 and A2L Certification Test Prep on October 7, 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.*