Comparison

Greenheck Toolbox vs Digiduct

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Greenheck Toolbox

This utility app provides two essential tools for HVAC professionals: a Fan Law Calculator to adjust fan performance based on changes in speed, and a Ductulator to quickly size ductwork. Easily calculate and determine duct dimensions and airflow with various input parameters.

Highlights
  • Fan Law Calculator
  • Ductulator App
  • Adjust fan performance
  • Size HVAC ductwork
  • Calculate airflow
  • Determine duct dimensions
Features
Read full description

Greenheck’s Toolbox includes a Fan Law Calculator and a Ductulator App. To use the Fan Law Calculator, input existing rpm, cfm, static pressure, and horse power. Modify any one measurement and the remaining three calculate. Greenheck’s Ductulator app allows you to quickly and easily size HVAC duct. Input your duct shape, rounded dimension, air temperature, elevation and select roughness. Next determine sizing by airflow or dimensions, select velocity or friction factor, input your volume, velocity, aspect ratio and calculate. Your results will be displayed.

About

Digiduct

This HVAC tool assists professionals with duct sizing calculations based on ASHRAE standards. It supports multiple duct shapes and offers intelligent features to ensure accurate and reliable designs for real-world scenarios.

Highlights
  • Duct sizing for rectangular, round, and flat oval ducts
  • Customizable dimensions with locked values
  • Duct location intelligence for context-aware sizing
  • Calculations based on CFM, pressure drop, or velocity
  • Alerts for exceeding pressure drop or velocity limits
Features
Read full description

The Digiduct app is a powerful tool designed for HVAC professionals, supporting everything from design calculations to real-time field verification. Built utilizing the equations and recommendations from the ASHRAE Fundamentals – Duct Design chapter, it ensures your calculations are accurate and reliable, saving you time and reducing errors. Key Features: • Multiple Shape Sizing Options: Supports sizing for rectangular, round, and flat oval ducts, offering flexibility for various duct designs. • Customizable Dimensions: For rectangular and oval ducts, users can lock in one dimension, and the app calculates the other, ensuring precise results based on CFM, pressure drop due to friction, or velocity. • Duct Location Intelligence: offers the user predefined parameters to use as starting point and reference when selecting duct sizes so users at HVAC experience level can make confident selections. Why Choose Digiduct? Unlike other duct sizing tools, Digiduct goes above and beyond. It doesn’t just provide basic size outputs—it evaluates the location and context of your duct (high-pressure vs. low-pressure, shaft vs. plenum), alerting you if your selection exceeds maximum pressure drop or velocity limits. This added layer of intelligence ensures higher accuracy and gives users confidence that their sizing is optimal for the application. Get the assurance of precision with Digiduct—designed to meet the demands of real-world HVAC scenarios.

Screenshots

Greenheck Toolbox2 screens
Digiduct4 screens

Verdict

The call

The clearest difference is rating: Digiduct at 4.6 against Greenheck Toolbox's 3.0. Digiduct also leads on ratings volume (11 vs 3). Greenheck Toolbox's advantage is monetization model (free vs ad-supported) and iOS requirement (7.0 vs 26.2). On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

ReceptionRating · Positive reviews · Number of ratings

Digiduct holds the better App Store score, 4.6 against 3.0. Both are backed by a comparable volume of ratings — 3 and 11 respectively.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 5, 2026 and October 16, 2026 respectively.

Scorecard4 real differences · 6 level
Greenheck Toolbox versus Digiduct: the parameters behind the verdict, then further details
ParameterGreenheck ToolboxDigiduct
PriceFreeFree
Rating3.0 (3 ratings)4.6 (11 ratings) — better
Positive reviews0.0% of reviews—
Number of ratings311 — better
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS7.0 — better26.2
Further details — not scored
Size2 MB4 MB
Age rating4+4+
DeveloperGreenheckSyska Hennessy Group

Customer experience

Greenheck Toolbox

All ratings3 ratings
Positive33.3%
Neutral33.3%
Negative33.3%
Written reviews9 reviews
Positive0.0%
Neutral22.2%
Negative77.8%

Digiduct

All ratings11 ratings
Positive90.9%
Neutral0.0%
Negative9.1%

In-app purchases

None

Greenheck Toolbox

No in-app purchases

None

Digiduct

No in-app purchases

Questions

Is Greenheck Toolbox free?
Greenheck Toolbox is free to download, with no in-app purchases.
Is Digiduct free?
Digiduct is free to download, with no in-app purchases.
Which has better reviews, Greenheck Toolbox or Digiduct?
Digiduct is rated higher. Greenheck Toolbox averages 3.0 out of 5 from 3 ratings, while Digiduct averages 4.6 from 11 ratings.
Do Greenheck Toolbox or Digiduct have ads?
Neither Greenheck Toolbox nor Digiduct shows ads.
Which is updated more often, Greenheck Toolbox or Digiduct?
Greenheck Toolbox ships an update every 2 months, and Digiduct every 2 months. Most recently, Greenheck Toolbox was updated on October 5, 2026 and Digiduct on October 16, 2026.

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