Carmel Software Corp.

What Carmel Software Corp. does

Carmel Software Corporation is a privately held software company founded in 1995 and headquartered in San Rafael, California, that develops HVAC engineering software for mobile, web, and desktop platforms. Its portfolio spans 40+ iOS and Android apps (cumulatively licensed 350,000+ times worldwide as of December 2021), including the ACCA-approved HVAC ResLoad-J load calculation engine, the HVAC Equipment Locator for equipment nameplate and maintenance tracking, and bundles such as HVAC Toolkit Ultimate (14 apps, $60) and HVAC Load Calc Bundle Plus (7 apps). Core technology includes the proprietary ESS Physics Engine — a custom equipment selection template developed over 20 years for 50+ HVAC manufacturers — and gbXML/IFC schema extensions contributed under ASHRAE 1815-TRP research. The cloud-based ResLoad-J and Equipment Locator services add project synchronization with role-based access (freemium for 2 cloud projects, paid tiers beyond).

The company operates three distinct go-to-market motions: consumer app store distribution via Apple App Store and Google Play at one-time license price points ($24–$60 per bundle); a sales-led custom software development practice serving Fortune 500 OEMs (Carrier, Trane Technologies, Honeywell, Mitsubishi Electric, Johnson Controls), industry associations (ASHRAE, SMACNA, IBPSA-USA, SFPE Foundation), and U.S. government agencies (DOE, U.S. Army); and a channel/white-label motion in which manufacturers and standards bodies co-brand or distribute Carmel-built applications. Revenue is generated through one-time mobile app licenses, tiered cloud subscriptions, professional services for custom development contracts, and licensing/white-label royalties. Sub-brands include Hands Down Software (desktop psychrometric software acquired 2024), BIMDrop (parts catalog platform launched 2019), and Schema Server (DOE-funded building energy auditing interoperability tool). In 2010, Carmel divested desktop engineering software source code to Autodesk (implemented into Revit MEP), retaining mobile and web rights, and has since rebuilt a desktop presence via the Hands Down Software acquisition.

Name

Carmel Software Corp.

Legal name

Carmel Software Corporation

Website

https://carmelsoft.com

Company type

Private

Founded year

1995

Operating status

Operating

Headcount range

11–50 employees

Short description

Carmel Software Corporation develops HVAC engineering and design software for mobile, web, and desktop platforms, serving HVAC professionals, manufacturers, standards organizations, and government agencies with 40+ calculation, sizing, and equipment selection tools.

Ownership category

akta.pro rank

Product category

HVAC Engineering Software

NAICS

Software Publishers (513210)

SIC

Services-Computer Programming Services (7371)

akta.pro primary industry

HVAC Controls & Optimization (Smart Thermostats, VAV, Chillers/Boilers Controls) (BPABAGAB)

akta.pro secondary industry

Demand Response, Utility Program Enrollment & Smart HVAC Optimization (HSAOANAJ)

Keywords

• Hvac calculation software
• Mobile engineering apps
• Hvac equipment selection
• Building energy analysis
• Custom software development

Headquarters

HQ city

San Rafael

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B and B2C

Offering type

Software

Cost components

Personnel, Technology or R&D, Marketing or Sales, Infrastructure, Operations

Revenue model

1. Mobile App Sales: Individual and bundled iOS/Android apps sold through Apple App Store and Google Play. Apps include HVAC load calculations, equipment sizing, psychrometrics, and equipment management.
2. Cloud Services Subscription: Tiered cloud storage and synchronization services for ResLoad-J and Equipment Locator projects. Free tier (2 projects), paid tiers for additional storage and team features.
3. Custom Software Development: Contracted software development services for OEMs, manufacturers, and government agencies. Projects include equipment selection software, IoT applications, and web-based tools.
4. Licensing and White-Label: Co-branded and white-labeled applications for ASHRAE, SMACNA, and other industry partners. Royalties and licensing fees from major HVAC manufacturers.

Pricing tiers

Go-to-market motion3 records

Distribution channels5 records

Marketing channels6 records

Core offering

Carmel Software Corp. develops, markets, and sells HVAC and engineering software products, including 40+ native iOS and Android mobile applications for field-based load calculations, duct/pipe sizing, psychrometric analysis, and refrigerant charging. In addition to packaged apps sold through Apple App Store and Google Play, the company provides custom software development services for HVAC manufacturers, industry associations, and government agencies, producing co-branded applications, equipment selection software powered by its proprietary ESS Physics Engine, BIM interoperability tools, and web-based portals for building energy compliance.

Product overview

Carmel Software Corp. is a software company specializing in HVAC and engineering design tools, offering a portfolio of 40+ mobile, desktop, and web-based software products. The core offerings include HVAC ResLoad-J (ACCA-approved Manual J8 load calculation app), HVAC Equipment Locator (equipment tracking and maintenance management), and HVAC Toolkit Ultimate (comprehensive bundle of 14 calculation tools). The company provides both consumer-facing mobile apps and custom software development services for enterprise clients including ASHRAE, SMACNA, Trane, Johnson Controls, and the U.S. Department of Energy. Services include HVAC equipment selection software, IoT development, gbXML support, and BIM family creation. The company has developed specialized tools such as ASHRAE Building EQ Web Portal, BIMDrop, and Schema Server for building energy analysis and interoperability. Carmel acquired Hands Down Software (psychrometric chart software) in 2024 and has licensed over 350,000 mobile apps worldwide.

Differentiator

Problem solved

Functional benefit

Brands

• Hands Down Software: Desktop psychrometric chart software acquired by Carmel in 2024
• BIMDrop
• Schema Server

Products and services

• HVAC ResLoad-J ACCA-approved HVAC cooling and heating load calculation mobile app that performs peak cooling and heating load calculations per ACCA Manual J8 for residential and light commercial buildings; includes cloud sync for project backup and sharing.
• HVAC Equipment Locator Mobile application for tracking, sharing, and customizing HVAC and building equipment nameplate and maintenance data across devices, with cloud synchronization for authorized user sharing; targets HVAC technicians and building maintenance managers.
• HVAC ResLoad-J Cloud Cloud synchronization and storage service for HVAC ResLoad-J projects, enabling backup, sharing, and multi-user collaboration with role-based access control (admin, technician, client). Free tier supports 2 cloud projects; paid tiers provide additional storage and team features.
• HVAC Residential Load Calcs HD iPad app for performing detailed heating and cooling load calculations for small commercial and residential buildings based on abridged Manual J8 methodology.
• HVAC Residential Load Calcs iPhone app for performing detailed heating and cooling loads based on Manual J8 methodology for residential buildings.
• HVAC Load Plus iPhone app for performing Manual J8 (abridged) load calculations for residential buildings.
• HVAC Quick Load Rule-of-thumb HVAC cooling and heating load calculation app for commercial, industrial, institutional, and residential buildings, providing fast approximation calculations.
• HVAC Duct Sizer Duct sizing calculator for quickly sizing HVAC duct runs with support for rectangular, round, or oval ducts, including velocity and friction loss calculations.
• HVAC PT Chart Pressure-temperature chart application displaying thermodynamic properties of 100+ refrigerants, including bubble and dew versions for azeotropic mixtures.
• HVAC Refrigerant Charge Refrigerant charging calculator for performing superheat and subcooling calculations, supporting 100+ refrigerants.
• Steam Tables Steam properties calculator for saturated and superheated steam, with 23+ input parameter combinations and steam-table-formula powered calculations.
• HVAC Psychrometric Plus Psychrometric calculation app for single-state and mixed-air calculations, with 20 input parameter combinations for each mode.
• HVAC Psychrometric LT Lite version of the psychrometric calculation app focused on single-state calculations with 20 input parameter combinations.
• HVAC Psych HD Interactive graphical psychrometric chart for iPad with customizable graph appearance, point plotting, process lines, and sensible heat ratio visualization.
• HVAC Pipe Sizer Plus Comprehensive pipe sizing bundle combining liquid, steam, and gas pipe sizing modules with built-in fitting equivalent length tables.
• HVAC Pipe Sizer Gas Plus Gas pipe sizing app for low (≤1.5 psi) and high (>1.5 psi) pressure gas piping systems.
• HVAC Pipe Sizer Gas High High pressure gas piping system sizing app for systems ≥1.5 psi.
• HVAC Pipe Sizer Gas Low Low pressure gas piping system sizing app for systems <1.5 psi.
• HVAC Pipe Sizer Liquid Liquid pipe sizing application for hydronic and other fluid pipe systems, supporting various pipe materials and fittings.
• HVAC Pipe Sizer Steam Steam pipe sizing application with bonus steam table calculator for saturated and superheated steam.
• HVAC ASHRAE 62.1 Commercial building ventilation calculator based on ASHRAE Standard 62.1-2016/2019 for minimum ventilation rate compliance.
• HVAC ResVent 62.2 Residential building ventilation requirements calculator following ASHRAE 62.2-2007 and 62.2-2010 standards.
• ASHRAE HVAC Psychrometric Chart Co-branded ASHRAE interactive graphical psychrometric chart app for iPad, available in IP and SI units.
• HVAC ASHRAE DFDB ASHRAE Duct Fitting Database app with 240+ fittings from the 2021 ASHRAE Handbook of Fundamentals for pressure loss calculations.
• ASHRAE 90.1 Web App Web-based Energy Cost Budget (ECB) Method compliance calculator for ASHRAE 90.1-2010 standard using the performance path approach.
• Custom Software Development Services Custom software development services for engineering and construction industries, including equipment selection software, HVAC IoT development, mobile energy auditing apps, and building energy analysis tools targeting manufacturers, government agencies, and standards bodies.
• HVAC Equipment Selection Software Custom HVAC equipment selection software development service powered by Carmel's ESS Physics Engine template, supporting humidification, dehumidification, VRF, and grow room equipment selection for manufacturers.
• ASHRAE Building EQ Web Portal Building energy benchmarking portal providing quick energy analysis to benchmark a building's energy performance against ASHRAE standards.
• BIMDrop Online parts-catalog and advertising engine specifically geared toward the building trades.
• Schema Server DOE-funded web-based tool that helps different DOE and private-company software tools share building energy auditing information through a unified schema server.
• MeeFog Energy Analysis Tool Desktop software tool for calculating energy usage and costs for adiabatic humidification equipment, performing 8760 hourly energy analysis.
• SMACNA Ductulator Web-based HVAC ductulator application developed for SMACNA and distributed through the SMACNA website.
• SMACNA Exhaust Design Graphical HVAC exhaust design software tool developed for SMACNA.
• HDPsyChart Desktop psychrometric chart software by Hands Down Software, acquired by Carmel in 2024; Version 9 released in April 2025.

Quantifiable outcome

• ACCA-approved load calculations accepted by municipalities and building authorities
• +1 more outcomes

Named customers14 records

Segments6 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

16 partnerships are on record, tiered core and minor.

• Hands Down SoftwarecoreStrategic or Co-development Partner · 1 January 2024In 2024, Carmel acquired Hands Down Software, a leader in desktop psychrometric chart software. This acquisition expanded Carmel's product portfolio in psychrometric analysis tools.
• SMACNAcoreStrategic or Co-development Partner · 1 January 2022SMACNA (Sheet Metal and Air Conditioning Contractors' National Association) awarded Carmel two software development contracts for a web-based HVAC ductulator and graphical HVAC exhaust design software tool.
• AutodeskcoreStrategic or Co-development Partner · 1 January 2010In 2010, Autodesk acquired Carmel Software's desktop-based engineering software assets. The acquired source code was implemented into Autodesk Revit MEP to perform building thermal analysis. Carmel retained rights to continue developing mobile and web versions of the software.
• ASHRAEcoreStrategic or Co-development PartnerLong-standing partnership where Carmel develops and maintains multiple co-branded mobile applications for ASHRAE standards (62.1, 62.2, 90.1, 140), the ASHRAE Building EQ Web Portal, and ongoing research contracts for schema development.
• IBPSA-USAminorStrategic or Co-development PartnerIBPSA-USA awarded Carmel a contract to develop a web-based software portal for ASHRAE Standard 140 compliance and validation, later expanded to include ASHRAE Standard 90.1-2019 PRM and ECB methods.
• SFPE FoundationminorStrategic or Co-development PartnerSociety of Fire Protection Engineers Foundation awarded Carmel a research grant to study integration of fire protection systems with BIM. Final report published March 2024.
• Carrier Corp.coreOEM/ Whitelabel/ Licensing PartnerCarrier licenses custom versions of Carmel apps and Carmel developed custom equipment selection software for Carrier Corporation (2018-2021).
• Trane TechnologiescoreOEM/ Whitelabel/ Licensing PartnerTrane Technologies (Ingersoll-Rand) partnered with Carmel for MAP iPad software integration and custom mobile applications for their distribution network.
• HoneywellcoreOEM/ Whitelabel/ Licensing PartnerHoneywell's Phoenix Controls division co-developed a comprehensive HVAC system energy analysis software tool (PC Optimizer) with Carmel. Also developed custom psychrometric calculator.
• Mitsubishi ElectriccoreOEM/ Whitelabel/ Licensing PartnerMitsubishi Electric hired Carmel to develop Diamond System Builder, a comprehensive VRF equipment selection software tool for their entire line of HVAC equipment.
• Johnson ControlscoreOEM/ Whitelabel/ Licensing PartnerJCI hired Carmel to develop a web-based JavaScript HVAC psychrometric calculator to aid in selection of their residential line of HVAC equipment.
• U.S. Department of EnergycoreStrategic or Co-development PartnerMultiple DOE-funded projects including SBIR grants for energy auditing software interop tools (Schema Server), gbXML development with NREL/PNNL, and building energy analysis tools. Won 2020 DOE grant for Schema Server development.
• MeeFog SystemsminorStrategic or Co-development PartnerIn Summer 2025, Carmel was awarded a contract by MeeFog Systems to develop a desktop software tool for adiabatic humidification equipment energy analysis, performing 8760 hourly energy analysis.
• Rinnai AmericaminorOEM/ Whitelabel/ Licensing PartnerRinnai America hired Carmel to develop a web-based heat load calculator for their residential and commercial product lines.
• SG AmericaminorOEM/ Whitelabel/ Licensing PartnerSG America hired Carmel to develop a web-based equipment selection software tool for their line of air-to-air heat exchangers for energy recovery ventilation equipment.
• DriSteemminorStrategic or Co-development PartnerDriSteem, a manufacturer of evaporative cooling and humidification equipment, hired Carmel to develop a web-based psychrometric chart software tool and API.

Scale indicators6 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Wrightsoft Right-Suite Universal: Wrightsoft's Right-Suite Universal is a long-standing residential HVAC design suite (Manual J/S/T/R/D plus energy) that overlaps closely with Carmel's HVAC ResLoad-J, Quick Load, and Duct Sizer apps in the same small-engineer and contractor segment.
• Elite Software: Elite Software publishes design and analysis programs (e.g., CHVAC, DUCTSIZE, HEAT) for HVAC load calculations and duct/pipe sizing. It competes head-to-head with Carmel's HVAC Toolkit Ultimate, Duct Sizer, and Pipe Sizer lines on desktop engineering desktops.
• Cool Calc / WATS4HVAC: Cool Calc and WATS4HVAC offer Manual J/S/D residential HVAC load calculation and duct sizing tools, directly competing with Carmel Software's HVAC ResLoad-J and HVAC Toolkit Ultimate products for the same HVAC engineer/contractor audience.
• EnergyGauge USA: EnergyGauge USA is a residential energy-rating/load calculation program built on DOE-2 that competes in the same ACCA-aligned residential HVAC and energy-auditing workflow as Carmel's ResLoad-J and ASHRAE 90.1 ECB Method app.

Broad incumbents

• DesignBuilder: DesignBuilder is an EnergyPlus-based building performance simulation suite used for ASHRAE 90.1 compliance and detailed energy modeling. It overlaps with Carmel's ASHRAE 140 validation portal, Building EQ, and energy-auditing tooling at the commercial simulation tier.
• Autodesk Revit MEP: Autodesk acquired Carmel's desktop HVAC source code in 2010 and embedded it into Revit MEP for building thermal analysis. Revit MEP is a broad-incumbent BIM platform whose HVAC thermal analysis features compete directly with Carmel's HVAC engineering suite in design firms.
• Carrier HAP (Hourly Analysis Program): Carrier's HAP is a commercial building HVAC load and energy analysis tool from one of Carmel's biggest OEM customers. It overlaps with Carmel's ASHRAE-aligned load calc, Building EQ, and energy analysis offerings, but sits inside a much broader Carrier enterprise software suite.
• Trane TRACE 700 / TRACE 3D Plus: Trane's TRACE platform is a full building energy modeling suite from another major Carmel OEM customer. It competes with Carmel's ASHRAE 90.1 ECB Method, Building EQ Portal, and custom energy analysis work in the commercial energy analysis market.

Emerging players

• Sefaira (by Trimble/Autodesk): Sefaira is an early-stage energy and HVAC sizing plugin that runs inside SketchUp and web tools. It intersects with Carmel's design-stage HVAC calculations and AS HRAE 90.1 checks as a SaaS-style competitor targeting architects and engineers.
• cove.tool: cove.tool is a cloud-based building performance analysis platform that focuses on early-stage architectural energy, daylighting, and HVAC sizing. It is an emerging alternative to Carmel's heavy-custom mobile/AS HRAE-load products for architects and designers.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/carmel-software-corporation

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Subsidiaries1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Carmel Software Corp.