# Viscosity Conversion vs Mean HVAC BS Tools

The clearest difference is price: Mean HVAC BS Tools at Free against Viscosity Conversion's $2.99. Mean HVAC BS Tools also leads on update cadence (every 2 months vs every 30 months). Viscosity Conversion's advantage is iOS requirement (13 vs 15.1). On ads, in-app purchases and device support there is nothing between them.

Mean HVAC BS Tools is free to download; Viscosity Conversion costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Viscosity Conversion ships an update every 30 months, Mean HVAC BS Tools every 2 months. The most recent releases landed on September 23, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | Viscosity Conversion | Mean HVAC BS Tools |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/mean-hvac-bs-tools/id6621189879/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 30 months | **Every 2 months** |
| Monetization | — | Paid |
| Size | 1 MB | 54 MB |
| Requires iOS | **13** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Mean HVAC Consulting & Design LLC](https://appshunter.io/developer/1761936254) |

## What reviewers say

### Viscosity Conversion

[App page](https://appshunter.io/ios/app/viscosity-conversion/id630288155)

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

**In-app purchases:** none


### Mean HVAC BS Tools

[App page](https://appshunter.io/ios/app/mean-hvac-bs-tools/id6621189879)

This utility app offers a suite of calculators for HVAC professionals, including psychrometric analysis, duct sizing, insulation R-value estimation, and air bypass calculations. It helps engineers and technicians quickly determine essential parameters for system design and analysis.

**Highlights:** Single Point Psychrometrics, Mixed Air Psychrometrics, Duct Calculator (CFM, Diameter, Friction, Velocity), Smallest Zone Calculator, Bypass Calculator (Cooling/Heating), IR Wall Insulation R-Value Estimation, Parallel R-Value Calculator, Unit Converter

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

**In-app purchases:** none


## Frequently asked questions

### Is Viscosity Conversion free?

Viscosity Conversion costs $2.99, with no in-app purchases.

### Is Mean HVAC BS Tools free?

Mean HVAC BS Tools is free to download, with no in-app purchases.

### Do Viscosity Conversion or Mean HVAC BS Tools have ads?

Neither Viscosity Conversion nor Mean HVAC BS Tools shows ads.

### Which is updated more often, Viscosity Conversion or Mean HVAC BS Tools?

Viscosity Conversion ships an update every 30 months, and Mean HVAC BS Tools every 2 months. Most recently, Viscosity Conversion was updated on September 23, 2026 and Mean HVAC BS Tools on September 12, 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.*