# DALC vs ASHRAE DFDB Lite

The clearest difference is update cadence: DALC at every 2 weeks against ASHRAE DFDB Lite's every 6 weeks. DALC also leads on review sentiment (15% vs 0%) and iOS requirement (6.0 vs 11.0). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

DALC ships an update every 2 weeks, ASHRAE DFDB Lite every 6 weeks. The most recent releases landed on October 8, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | DALC | ASHRAE DFDB Lite |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.2 (26 ratings)](https://appshunter.io/ios/app/dalc/id427624076/reviews)** | — |
| Number of ratings | **26** | — |
| Positive reviews | **14.8% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 6 weeks |
| Monetization | Free | Free |
| Size | 10 MB | 7 MB |
| Requires iOS | **6.0** | 11.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC.](https://appshunter.io/developer/427624079) | [ASHRAE, Inc.](https://appshunter.io/developer/375374912) |

## What reviewers say

### DALC

[App page](https://appshunter.io/ios/app/dalc/id427624076)

This tool helps engineers, architects, designers, and contractors accurately estimate air leakage from ductwork. It simplifies determining pass/fail for duct air leakage tests and allows combining multiple duct sections for total leakage calculations, adhering to industry standards.

**Highlights:** Estimate ductwork air leakage, Determine DALT pass/fail, Combine multiple duct sections, Calculate total allowable leakage, Provides suggested leakage classes, Compliant with industry standards

**Features:** macOS Compatibility

**In-app purchases:** none


### ASHRAE DFDB Lite

[App page](https://appshunter.io/ios/app/ashrae-dfdb-lite/id6475053772)

Calculate pressure loss for a selection of ASHRAE duct fittings. Create projects, customize inputs, and generate reports with spreadsheet attachments. Supports both I-P and SI units and works on iPhone and iPad.

**Highlights:** Pressure loss calculations for ASHRAE fittings, Individual project creation, Customizable input parameters, Fitting code search feature, Display and email reports, I-P and SI unit support, iPhone and iPad compatible

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is DALC free?

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

### Is ASHRAE DFDB Lite free?

ASHRAE DFDB Lite is free to download, with no in-app purchases.

### Do DALC or ASHRAE DFDB Lite have ads?

Neither DALC nor ASHRAE DFDB Lite shows ads.

### Which is updated more often, DALC or ASHRAE DFDB Lite?

DALC ships an update every 2 weeks, and ASHRAE DFDB Lite every 6 weeks. Most recently, DALC was updated on October 8, 2026 and ASHRAE DFDB Lite on October 6, 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.*