# Allday HVAC Calc vs Data Center Engineer Toolkit

The clearest difference is update cadence: Data Center Engineer Toolkit at every 2 days against Allday HVAC Calc's every 3 months. Allday HVAC Calc's advantage is iOS requirement (15.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Allday HVAC Calc sells 1 one-off in-app purchase and Data Center Engineer Toolkit sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Allday HVAC Calc ships an update every 3 months, Data Center Engineer Toolkit every 2 days. The most recent releases landed on October 22, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | Allday HVAC Calc | Data Center Engineer Toolkit |
| --- | --- | --- |
| 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 | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 days** |
| Monetization | Free | — |
| Size | 38 MB | 1 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Dmitrii Pankov](https://appshunter.io/developer/1677093604) | [Shanghai Sheyuan Network Technology Co., Ltd.](https://appshunter.io/developer/1560626858) |

## 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 |


### Data Center Engineer Toolkit

[App page](https://appshunter.io/ios/app/data-center-engineer-toolkit/id6761987963)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Calculators | $12.99 | one-time |


## Frequently asked questions

### Is Allday HVAC Calc free?

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

### Is Data Center Engineer Toolkit free?

Data Center Engineer Toolkit is free to download, with in-app purchases available.

### Do Allday HVAC Calc or Data Center Engineer Toolkit have ads?

Neither Allday HVAC Calc nor Data Center Engineer Toolkit shows ads.

### Which is updated more often, Allday HVAC Calc or Data Center Engineer Toolkit?

Allday HVAC Calc ships an update every 3 months, and Data Center Engineer Toolkit every 2 days. Most recently, Allday HVAC Calc was updated on October 22, 2026 and Data Center Engineer Toolkit on October 20, 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.*