# Allday HVAC Calc vs Spin Xpert

The clearest difference is in-app purchases: Spin Xpert at none against Allday HVAC Calc's 1. Spin Xpert also leads on update cadence (every 3 weeks vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Allday HVAC Calc sells 1 one-off in-app purchase. Spin Xpert asks for nothing beyond the download.

Allday HVAC Calc ships an update every 3 months, Spin Xpert every 3 weeks. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Allday HVAC Calc | Spin Xpert |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/allday-hvac-calc/id6446276144/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Monetization | Free | — |
| Size | 38 MB | 136 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Dmitrii Pankov](https://appshunter.io/developer/1677093604) | [AHMED MOHAMED ABDALLAH EL SNOSEY](https://appshunter.io/developer/947633967) |

## What reviewers say

### Allday HVAC Calc

[App page](https://appshunter.io/ios/app/allday-hvac-calc/id6446276144)

This app offers three specialized modules for HVAC engineers: a psychrometric calculator for air properties, a pipe calculator for fluid dynamics and selection, and a duct calculator for air speed and pressure loss. It provides detailed calculations and reference formulas in both SI and IP units.

**Highlights:** Psychrometric air property calculations, Pipe velocity and pressure loss calculation, Duct speed and pressure loss calculation, Interdependent parameter calculations, Reference formulas included, SI and IP unit support

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Allday Design Assist | $4.99 | one-time |


### Spin Xpert

[App page](https://appshunter.io/ios/app/spin-xpert/id6502615080)

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

**In-app purchases:** none


## Frequently asked questions

### Is Allday HVAC Calc free?

Allday HVAC Calc is free to download, with in-app purchases available.

### Is Spin Xpert free?

Spin Xpert is free to download, with no in-app purchases.

### Do Allday HVAC Calc or Spin Xpert have ads?

Neither Allday HVAC Calc nor Spin Xpert shows ads.

### Which is updated more often, Allday HVAC Calc or Spin Xpert?

Allday HVAC Calc ships an update every 3 months, and Spin Xpert every 3 weeks. Most recently, Allday HVAC Calc was updated on November 3, 2026 and Spin Xpert on November 4, 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.*