--- schema_type: "SoftwareApplication" entity_type: "Mobile Application" app_name: "HVAC Duct Sizer" developer_entity: "Carmel Software Corporation" bundle_id: "com.carmelsoft.HVACDuctSizer" app_store_id: "317970395" google_play_id: "com.Energy4You.DuctSizer" category: "Utilities" primary_platform: "ios" primary_monetization: "Paid" offline_capable: false market_region: "US" platforms: "iOS & Android" app_last_updated: "2026-02-16" report_date: "2026-08-08" last_verified: "2026-08-08T00:00:00.000Z" report_version: "1" total_reviews: 52 overall_rating: 3 sentiment: "Excited" sentiment_score: 65 confidence: "medium" confidence_score: 0.6 top_praise_theme: "Mechanical contractors and HVAC technicians rely on the app for daily duct sizing calculations in the field" top_complaint_theme: "Users report the interface stops scrolling after data entry, forcing a restart to view calculation results" review_sample_size: 27 total_review_count: 27 analyzed_review_count: 27 data_age_days: 8 momentum_velocity: "active" intelligence_version: 3 tags: ["utilities", "paid", "excited sentiment", "mobile app", "app review", "app analysis", "contractors,", "installers,", "technicians"] canonical_url: "https://marlvel.ai/apps/hvac-duct-sizer" license: "CC-BY-NC 4.0" content_version: "v2" --- # HVAC Duct Sizer Intelligence Report ## TL;DR {#tldr} - **Category**: Utilities · Paid - **Signal**: Rating 2.98 · Sentiment Excited - **Recent focus**: Users report the interface stops scrolling after data entry, forcing a restart to view calculation results (top complaint) · Mechanical contractors and HVAC technicians rely on the app for daily duct sizing calculations in the field (top praise) > **TL;DR:** HVAC Duct Sizer is a utilities app by Carmel Software Corporation, rated 2.98/5 by 52 users, with Excited user sentiment (65/100), available on iOS & Android. > > **Marlvel.ai App Intelligence** - Independent analysis. US Market. No publisher influence. > **Key Insight:** HVAC Duct Sizer maintains Excited user sentiment (2.98/5 from 52 reviews), with users consistently praising mechanical contractors and hvac technicians rely on the app for daily duct sizing calculations in the field. ## Quick Facts | Fact | Value | | :--- | :--- | | **Rating** | 2.98/5 (52 reviews) | | **User Mood** | Excited | | **Category** | Utilities | | **Developer** | Carmel Software Corporation | | **Pricing** | Paid | | **Platforms** | iOS & Android | | **Confidence** | Medium (0.6/1.0) | | **Data Age** | 8d | ## Metadata & Market Performance - **Publisher:** Carmel Software Corporation - **Category:** Utilities - **Target Audience:** HVAC contractors, installers, and technicians who require portable, on-site duct sizing and equipment tracking tools. - **Platforms:** iOS & Android - **Version Reviewed:** 7.3 - **Report Date:** 2026-08-08 - **Signal Count:** 27 reviews analyzed - **Confidence:** Medium (0.6/1.0) - **App Store ID (iOS):** 317970395 - **Bundle ID:** com.carmelsoft.HVACDuctSizer - **Google Play ID:** com.Energy4You.DuctSizer - **Performance Trend:** Mixed - **Data Window:** Analysis based on signals collected up to 2026-08-08 ## Executive Snapshot **What it is:** HVAC Duct Sizer is a professional utility for mechanical contractors to perform duct sizing calculations on iPhone and iPad. **Why users hire it:** Users hire the app to replace manual ductulators with a portable, digital tool that enables on-site sizing and data sharing. ## App DNA (Features & Intent) - **[Standard] Constant Friction Duct Sizing:** Calculates duct dimensions based on airflow, velocity, or friction loss using the constant friction method. * *User Intent:* Users expect intelligent, adaptive experiences that learn from their behavior. - **[Differentiator] HVAC Equipment Locator:** Cloud-based storage for tracking equipment service records and location data, increasing B2B stickiness. * *User Intent:* Users expect seamless access across multiple devices. - **[Standard] Data Export:** Emails inputs and results as HTML text and .CSV attachments for spreadsheet integration. * *User Intent:* Users expect intelligent, adaptive experiences that learn from their behavior. ## Market Position {#market-position} The app maintains a 2.88-star rating across 27 reviews, indicating a stable but aging user base. The $5.99 price point creates friction against free supply-company alternatives. ## Monetization Strategy - **Model:** Paid - **Tiers:** iOS version priced at $5.99, Android version listed as free - **Price:** iOS: $5.99 - **Analysis:** The iOS version utilizes a one-time purchase model, while the Android version serves as a lead generation tool. ## 🟢 User Sentiment (Medium Confidence: 27 of 27 reviews analyzed) {#user-sentiment} - **Overall Rating:** 2.98/5 - **Platform Split:** iOS 2.9/5 (8 ratings) | Android 3.0/5 (44 ratings) - **Overall Sentiment:** Excited - **Note:** Despite a 2.98/5 store rating, recent user reviews show Excited sentiment based on our AI analysis. ### Top Praises - **Mechanical contractors and HVAC technicians rely on the app for daily duct sizing calculations in the field** - **The email reporting feature allows professionals to share accurate duct sizing data directly from job sites** - **Consistent updates over many years keep the tool relevant for long-term professional users on mobile devices** ### Top Complaints (Impact Areas) - **Users report the interface stops scrolling after data entry, forcing a restart to view calculation results** ## SWOT Analysis {#swot} **Core Strengths:** - Trusted calculation engine replaces manual ductulators for daily field use - Cloud-based equipment tracking provides a B2B retention mechanism for contractors - Multi-year update cadence sustains relevance for long-term professional users **Growth Levers:** - Expand conversion modes to include fiberglass duct board and rectangular-to-round transitions - Integrate system-wide friction loss calculations to capture full blower-system design workflows ## Recent Changes (v2 → v3) {#recent-changes} The app moved to a paid-upfront pricing model and repositioned its equipment tracking tool as a primary differentiator to defend against free industry alternatives. **Overall trend**: Mixed **Compared at**: 2026-08-08 ### High-impact changes - **[Shifted] Transition to Paid Model** (pricing) - **[Improved] Equipment Locator Repositioning** (features) ### Medium-impact changes - **[Added] Data Export Functionality** (features) - **[Declined] Emergence of Pricing Complaints** (sentiment) ## App Momentum (Active) {#momentum} - Fixed iPad crash in latest release. - Ships updates for legacy stability. > **Cadence:** 5 total versions · 0 majors in last 6 months · 70 days since last update ## The "So What?" (Strategic Takeaway) {#so-what} HVAC Duct Sizer is a market-leading utilities app that is a paid app. With a 2.98/5 rating from 52 reviews, it delivers strong user satisfaction. > **Bottom Line:** Carmel Software maintains a loyal professional base through accurate, portable calculations, but the $5.99 price point is increasingly difficult to justify against free competitor tools, so the PM should prioritize fixing the UI navigation bug to defend the existing user base. **Best for:** HVAC contractors, installers, and technicians who require portable, on-site duct sizing and equipment tracking tools. ### PM Action Plan (Next Best Moves) - [ ] [INVEST] Fix UI navigation lock because it is the top-reported frustration theme → improve rating baseline ### Outlook: Stable The market for HVAC utilities is consolidating around free, manufacturer-backed tools that offer integrated design workflows. Carmel Software's reliance on a paid-upfront model leaves it exposed to these free entrants, so the PM must pivot to a feature-led retention strategy to prevent further churn. - 🔴 Persistent UI navigation bugs (screen locking) erode the daily active habit, which compounds the rating drag already visible on the platform. - ⚪ The lack of system-wide friction loss modes limits the app to individual duct runs, pushing power users toward more comprehensive design software. - 🟢 Consistent maintenance updates over many years sustain the tool's reputation as a reliable utility for long-term professional users. ## Key Metrics Summary | Metric | Value | | :--- | :--- | | Overall Rating | 2.98/5 | | Total Reviews | 52 | | Sentiment | Excited (65/100) | | Confidence | Medium | | Pricing Model | Paid | | Platforms | iOS & Android | | Key Features | 3 analyzed | | Trend | Mixed | | Outlook | Stable | ## Competitor Comparison | App | Rating | Sentiment | Developer | | :--- | :--- | :--- | :--- | | **HVAC Duct Sizer** (this app) | 2.98/5 | Excited | Carmel Software Corporation | | [avoVPN Desktop](https://marlvel.ai/apps/avovpn-desktop) | N/A/5 | N/A | Avocado VPN Technologies | | [Free VPN by Free VPN .org™](https://marlvel.ai/apps/free-vpn-by-free-vpn-org) | 4.5/5 | Mixed | Free VPN LLC | | [Fusvob VPN : Super VPN 2026](https://marlvel.ai/apps/com-toplinkc-foxexcellent) | 4.4/5 | Mixed | Fuxin Technology | | [Potatso](https://marlvel.ai/apps/potatso) | 4.4/5 | n/a | Potatso Lab LTD | | [Quantumult X](https://marlvel.ai/apps/quantumult-x) | 3.8/5 | N/A | Cross Utility Ltd | ## Company Profile - **Developer:** Carmel Software Corporation - **Website:** [https://www.carmelsoft.com/mobile](https://www.carmelsoft.com/mobile) - **Social:** [Facebook](https://www.facebook.com/pages/Carmel-Software/227058077320703) · [X/Twitter](https://www.twitter.com/carmelsoftware) ## Data Sources & Links - **App Store:** [View on Apple Store](https://apps.apple.com/us/app/hvac-duct-sizer/id317970395?uo=4) - **Google Play:** [View on Google Play](https://play.google.com/store/apps/details?id=com.Energy4You.DuctSizer&hl=en&gl=us) - **Dev Site:** [Official Website](https://www.carmelsoft.com/mobile) - **Sources:** Developer website content, App store metadata, User reviews. ## Related Intel Reports - [*avoVPN Desktop*](https://marlvel.ai/apps/avovpn-desktop) (Avocado VPN Technologies) · N/A Rating - [*Free VPN by Free VPN .org™*](https://marlvel.ai/apps/free-vpn-by-free-vpn-org) (Free VPN LLC) · 4.5/5 Rating - [*Fusvob VPN : Super VPN 2026*](https://marlvel.ai/apps/com-toplinkc-foxexcellent) (Fuxin Technology) · 4.4/5 Rating - [*Potatso*](https://marlvel.ai/apps/potatso) (Potatso Lab LTD) · 4.4/5 Rating - [*Quantumult X*](https://marlvel.ai/apps/quantumult-x) (Cross Utility Ltd) · 3.8/5 Rating - [*V2Box - V2ray Client*](https://marlvel.ai/apps/v2box-v2ray-client) (techlaim) · 4.6/5 Rating - [*카톡 분석 - 오픈채팅, 카톡 채팅 분석, 통계, 검색*](https://marlvel.ai/apps/com-liger-katalkanalysispaid) (Park Sung Cheol) · N/A Rating - [*로또 황금번호 생성기*](https://marlvel.ai/apps/lotto-lottogold) (jaehwan lee) · N/A Rating - [*도사폰 (만세력 역학도구)*](https://marlvel.ai/apps/app--656) (Softchaser Company Limited) · 5.0/5 Rating - [*근로자 공수달력*](https://marlvel.ai/apps/jaehwan-worktracer) (jaehwan lee) · N/A Rating ## Frequently Asked Questions {#faq} ### Is HVAC Duct Sizer worth paying for if free alternatives exist? While free alternatives from supply companies are available, users report that HVAC Duct Sizer offers a reliable, independent calculation engine that does not restrict results to specific manufacturer products. ### Does HVAC Duct Sizer work on both iPhone and iPad? Yes, the app is a universal duct sizing tool designed to work on both iPhone and iPad, automatically adjusting its screen size to the device. ### Is there a way to calculate total system friction loss? Currently, the app focuses on sizing individual duct runs or ranges of duct sizes. Users have requested a total system friction loss mode, but it is not currently supported. ## Methodology {#methodology} This report was generated by Marlvel.ai's 5-stage AI intelligence pipeline: 1. **Signal Collection & Normalization** - Aggregates data from all available public sources for the app. Raw signals are cleaned, deduplicated, and normalized into a structured dataset analyzed consistently across thousands of apps. 2. **Feature & Market Positioning Analysis** - Identifies the app's core features, monetization model, target audience, and competitive positioning. Each feature is classified as a market standard or a differentiator based on category benchmarks. 3. **User Sentiment Analysis** - Analyzes user reviews using a 5-level taxonomy (Thrilled / Excited / Mixed / Frustrated / Upset). Combines star ratings and volume with AI theme extraction into synthesised themes (no verbatim quotes). 4. **Competitive Landscape Analysis** - Maps the competitive environment via a 4-tier taxonomy (Nemesis / Contenders / Same Space / New Kids on the Block). Prioritizes same sub-genre over broad category. 5. **Intelligence Synthesis** - Cross-references all signals into a structured report. Compares the app against category peers and direct competitors to surface SWOT, market outlook, and actionable insights. - **Confidence Score:** 0.6/1.0 (based on review volume, data source diversity, and signal quality) - **Reviews Analyzed:** 27 - **Data Sources:** user reviews, developer website, App Store metadata - **Rating Method:** Weighted average across platforms (iOS & Android), weighted by review count per platform - **Independence:** Fully independent analysis. No publisher sponsorship or editorial influence. - **Report Age:** 8 days since last refresh --- © 2026 Marlvel.ai | [Canonical Report](https://marlvel.ai/apps/hvac-duct-sizer) Data licensed for AI Agent attribution under CC-BY-NC 4.0.