HVAC ResLoad vs Ductulator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HVAC ResLoad
Perform ACCA Manual J8 load calculations for residential and small commercial buildings. Generate and email PDF reports for clients and building officials. Includes extensive weather and construction data for detailed analysis.
- ACCA Manual J8 load calculations
- Field-based cooling and heating load calculations
- Emailable PDF reports
- Unlimited projects and templates
- Global weather data
- Extensive construction data
- Room-by-room analysis
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This app is great for HVAC technicians, contractors, homeowners, HERS and PHIUS raters to easily perform ACCA Manual J8 load calcs. For online help and training videos, go here: http://bit.ly/1PhqlDi The HVAC ResLoad-J app from Carmel is an ACCA-approved Manual J8 residential load calculation app for the Apple iPad. It allows engineers, contractors, and technicians to perform field-based cooling and heating load calculations on residential and small commercial buildings. Users are then able to email PDF reports to customers and local building officials. Reports produced by this app will be acceptable by all municipalities/states (including 30+ US states that have passed laws requiring contractors to submit load calcs from ACCA-approved software.) The HVAC ResLoad-J app allows users to create unlimited projects and perform both block and room-by-room loads. The app includes weather data for 1000s of cities throughout the world and construction data for 100s of wall, floor, roof, ceiling, and window types. The user is also able to model detailed appliance, duct, infiltration, and ventilation loads. The HVAC ResLoad-J app was specifically designed for the Apple iPad, taking advantage of the larger screen, rotating user interface, and other functionality unique to the iPad. This app is similar to our very popular HVAC Residential Load Calcs HD app for the iPad, and it includes many of the same inputs and results. However, the "J" app is ACCA-approved, and thus requires much more detailed analysis of the building. Other features include: 1. Includes a 1000+ world-wide city weather database 2. Allows you to create and store an unlimited number of projects. You can also re-use existing projects as templates for new projects. 3. Includes data for 100s of construction types for walls, roofs, floors, doors, windows, skylights, and ceilings. 4. Allows you to specify an unlimited # of building envelope types (i.e. – doors, walls, roofs, floors, ceilings), window types, and skylight types for each building. 5. Allows you to input individual home appliance information. 6. Allows you to instantly view total heating and cooling load results as you update input data. 7. Allows you to view comprehensive cooling and heating load breakdown reports including breakdown by envelope load, window load, skylight load, infiltration load, ventilation load and internal load contributions. 8. Also performs room-by-room cooling and heating load calc analysis 9. Includes the ability to display a wide variety of on-screen reports including checksum reports (ie – BTUh/SqFt, SqFt/Ton, etc.), complete heating and cooling load breakdown reports, and even graphically-pleasing pie charts showing cooling and heating load breakdowns. These reports can be converted to PDFs and emailed from right within the app. 10. Includes the ability to display a comprehensive HTML report that you can email to yourself or others, and it also includes a spreadsheet attachment that you can open in Excel to create customized reports. 11. Includes the ability to display units in either English (IP) or Metric (SI). 12. As of 2020, includes new project input reports that allow you to print or export to PDF via email. The benefits of using this app are numerous including: 1. Great for use out in the field. Quickly size heating and cooling equipment, show the client, then email the results back to your office for further analysis. 2. Show off your advanced on-screen reports to clients convincing them you are using cutting-edge technology. 3. Save time by inputting information in the field and then returning to your office to perform more in-depth analysis. 4. Submit reports to local municipalities that require ACCA-approved Manual J8 residential load calcs for equipment replacement. Bonus: The HVAC ResLoad-J app now includes our popular HVAC Equipment Locator app built right in! Click here for details about that app: http://bit.ly/1a2RskH
Ductulator
Instantly calculate HVAC duct sizes based on airflow, friction rate, or velocity. This tool provides accurate duct dimensions in seconds without needing charts, supporting various duct types and units.
- Instant duct sizing
- Friction rate or velocity calculation
- Multiple valid duct dimensions
- IP and SI units support
- Detailed sizing mode
- Rectangular, circular, and flexible ducts
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Size HVAC ducts instantly using airflow, friction or velocity. Get accurate duct dimensions in seconds — no charts required. • Get a range of suitable duct sizes based on friction rate or velocity. • Get multiple valid duct dimensions instantly. • Tap on Friction Rate or Velocity to toggle between calculation methods. • IP and SI units. • Detailed sizing mode to adjust the duct dimensions and air flow rates. • Supports rectangular, circular and flexible ducts. • Automatic friction and velocity updates. Calculations are based on standard air 0.075 lb/ft3 (1.2 kg/m3) in clean galvanized steel or non-metallic flexible ducts. Any feedback is welcome, and will be the basis for future updates.
Screenshots
Verdict
The clearest difference is price: Ductulator at $3.99 against HVAC ResLoad's $199.99. Ductulator also leads on rating (4.7 vs 3.4) and ratings volume (361 vs 8). HVAC ResLoad's advantage is iOS requirement (15.6 vs 18.6). On review sentiment, ads, in-app purchases and device support 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
HVAC ResLoad costs $199.99 and Ductulator $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Ductulator holds the better App Store score, 4.7 against 3.4. That said, the two scores are not equally well evidenced: Ductulator has 361 ratings behind it against 8, so its average is the more settled of the two. Written reviews split almost evenly too, at 50% and 50% positive.
HVAC ResLoad ships an update every 4 months, Ductulator every 2 months. The most recent releases landed on October 29, 2026 and November 3, 2026 respectively.
| Parameter | HVAC ResLoad | Ductulator |
|---|---|---|
| Price | $199.99 | $3.99 — better |
| Rating | 3.4 (8 ratings) | 4.7 (361 ratings) — better |
| Positive reviews | 50.0% of reviews | 50.0% of reviews |
| Number of ratings | 8 | 361 — better |
| Update frequency | Every 4 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Best chart rank | — | #123 — better |
| Devices | iPad | iPhone, iPad — better |
| Requires iOS | 15.6 — better | 18.6 |
| Further details — not scored | ||
| Size | 23 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Carmel Software Corporation | Wassim Murr |
Customer experience
HVAC ResLoad
Ductulator
Bugs and requests
HVAC ResLoad
Not enough reviews yet to summarise bugs or requests.
Ductulator
Reported bugs
4 issues- Decimal point doesn't work on calculator
- New flex option isn't working properly
- Friction rate can't be changed in the latest version
- Skips duct sizes (e.g., 24-26)
Requested features
5 requests- Ability to pick duct size and see CFM
- Include flat oval ducts
- Option to select round or square duct
- Ability to enter duct size and get CFM
- Option for flex duct
In-app purchases
HVAC ResLoad
No in-app purchases
Ductulator
No in-app purchases
Questions
Is HVAC ResLoad free?
Is Ductulator free?
Which has better reviews, HVAC ResLoad or Ductulator?
Do HVAC ResLoad or Ductulator have ads?
Which is updated more often, HVAC ResLoad or Ductulator?
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