Comparison

DuctSizer vs HVAC Tools PT Chart

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

Head to head
About

DuctSizer

This utility app provides a quick and accurate ductulator for calculating equivalent round and rectangular duct sizes. It supports both Imperial and SI units, offering a simple finger-slide interface for fast computations.

Highlights
  • Quick duct size calculations
  • Accurate results
  • Equivalent round and rectangular sizes
  • IP and SI unit support
  • Finger slide interface
Features
Read full description

The Duct Sizer is a productivity app developed by Nopparat Katkhaw. The app is a simplest and quickest ductulator. Perform quick calculation and accurate results. Use the finger slide for quick calculations. Shows equivalent round and rectangular duct sizes. Compatible with IP and SI units. We would very much like your feedback! Pleas contacts Facebook page: https://www.facebook.com/UP.Energy4You

About

HVAC Tools PT Chart

Features
Read full description

Gauge is a field toolkit for HVAC and refrigeration technicians: a pressure-temperature chart for 10 refrigerants, superheat and subcooling calculators, troubleshooting checklists and a service call log with PDF reports. PT CHART - R-410A and R-22 free; R-134a, R-407C, R-404A, R-32, R-454B, R-290, R-438A and R-422D with Pro - Look up the saturation temperature for a pressure, or the pressure for a temperature - Scroll the full table from -40ยฐF, with safety notes for the A2L (R-32, R-454B) and A3 (R-290) refrigerants CALCULATORS - Superheat: suction pressure and suction line temperature give the saturation temperature and the superheat - Subcooling: liquid line pressure and liquid line temperature - Temperature split: return and supply air - Ohm's Law: enter any two of volts, amps, ohms and watts - Pro: airflow (required CFM from BTU/h or tons and the temperature split), duct sizing (round and rectangular sizes from CFM and air velocity), capacitor check (measured against rated ยตF) and voltage drop (copper wire by AWG, one-way length, amps and supply voltage) Superheat, subcooling, temperature split, capacitor and voltage drop results are color-coded against typical ranges, with what to check next. SERVICE CALL LOG - Customer or address, complaint, system type, make and model - Suction and liquid pressure, superheat, subcooling, suction line, liquid line, supply and return air temperatures, compressor amps - Your diagnosis, the work performed, refrigerant type and amount, parts, notes, cost and time on the job - Free: up to 10 service calls. Pro: unlimited calls, search, and a PDF service report with your name and certification that you can share with the customer REFERENCE - Step-by-step checklists: AC not cooling (free), furnace not heating and heat pump not heating (Pro) - Typical ranges for superheat, subcooling, temperature split and compressor amps - Refrigerant facts: GWP, A2L or A3 safety class and phase-down status - System types, a copper wire ampacity table and an EPA 608 overview (certification types and key rules) AI ADVISOR (PRO) Describe a symptom or a set of readings and get a short written answer from an AI model. It sends only the message you type and needs an internet connection. AI answers can be wrong: check them against your own readings and the equipment manufacturer's data. GOOD TO KNOW - Gauge works in US units: ยฐF, psig, CFM, inches, feet, AWG and pounds - The PT chart, calculators, reference and service log work without a connection GAUGE PRO Free: the PT chart for R-410A and R-22, the superheat, subcooling, temperature split and Ohm's Law calculators, up to 10 service calls, the AC checklist and the reference tables. Pro adds the other 8 refrigerants, the airflow, duct sizing, capacitor and voltage drop calculators, unlimited service calls with search and PDF reports, the furnace and heat pump checklists and the AI Advisor. In the US, Gauge Pro is $4.99 a month or $39.99 a year (US prices; other countries see their own price in the app). Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period. Manage them in your App Store account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

DuctSizer4 screens
HVAC Tools PT Chart4 screens

Verdict

The call

The clearest difference is price: HVAC Tools PT Chart at Free against DuctSizer's $4.99. DuctSizer's advantage is in-app purchases (none vs 3) and update cadence (every 4 days vs every 3 months). On ads there is nothing between them.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

HVAC Tools PT Chart is free to download; DuctSizer costs $4.99 up front. HVAC Tools PT Chart sells 3 in-app purchases, starting at $4.99 per month. DuctSizer asks for nothing beyond the download.

UpkeepUpdate frequency

DuctSizer ships an update every 4 days, HVAC Tools PT Chart every 3 months. The most recent releases landed on October 14, 2026 and October 20, 2026 respectively.

Scorecard5 real differences ยท 3 level
DuctSizer versus HVAC Tools PT Chart: the parameters behind the verdict, then further details
ParameterDuctSizerHVAC Tools PT Chart
Price$4.99Free โ€” better
Positive reviews100.0% of reviewsโ€”
Update frequencyEvery 4 days โ€” betterEvery 3 months
AdsNoNo
In-app purchasesNo โ€” betterYes
MonetizationPaidโ€”
DevicesiPhone, iPad, iPod โ€” betteriPhone
Requires iOS12.0 โ€” better18
Further details โ€” not scored
Size57 MB9 MB
Age rating4+4+
DeveloperMulberrysoftKarol Jaworski

In-app purchases

None

DuctSizer

No in-app purchases

3 purchases

HVAC Tools PT Chart

Subscriptions3
  • Gauge Pro$4.991 Month
  • Gauge Pro1 Year trial$39.991 Year
  • Gauge Pro$39.991 Year

Questions

Is DuctSizer free?
DuctSizer costs $4.99, with no in-app purchases.
Is HVAC Tools PT Chart free?
HVAC Tools PT Chart is free to download, with in-app purchases available.
Do DuctSizer or HVAC Tools PT Chart have ads?
Neither DuctSizer nor HVAC Tools PT Chart shows ads.
Which is updated more often, DuctSizer or HVAC Tools PT Chart?
DuctSizer ships an update every 4 days, and HVAC Tools PT Chart every 3 months. Most recently, DuctSizer was updated on October 14, 2026 and HVAC Tools PT Chart on October 20, 2026.

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