FieldCalc HVAC vs Meridian
Side-by-side comparison of features, pros & cons, pricing, and community votes (2026).
🏆 Meridian leads with 463 upvotes

Offline HVAC calculator: R-454B PT, superheat, duct, load
FieldCalc HVAC is a robust offline calculator designed specifically for HVAC professionals working in the field. It offers comprehensive tools for R-454B PT charts, superheat and subcooling calculations, duct sizing, load estimates, and psychrometrics, all accessible without an internet connection. Its offline capability makes it ideal for technicians on rooftops or in remote locations where connectivity is limited. The app provides free access to essential PT charts for R-454B, R-32, and R-410A refrigerants, along with a unit converter for quick conversions. For more advanced features, users can opt for a one-time purchase of $9.99, unlocking all calculators, support for 13 refrigerants, and PDF export options. Designed with simplicity and efficiency in mind, FieldCalc HVAC is a must-have tool for HVAC techs seeking reliable, offline calculations that streamline their workflows and improve accuracy.
Pros
- Offline functionality ensures usability in remote or connectivity-challenged environments
- One-time purchase model with no subscriptions, ads, or tracking
- Wide range of features including refrigerant charts, load calculations, duct sizing, and psychrometrics
- Supports multiple refrigerants and offers PDF export for documentation
- Free basic PT charts and unit converter for quick reference
Cons
- Limited to HVAC-specific calculations; not a general-purpose tool
- One-time fee may be a barrier for some users expecting free or subscription-based models
- Interface may be basic compared to more comprehensive software solutions
Best for
- • Performing refrigerant superheat/subcooling calculations on-site
- • Sizing ducts accurately during installation or maintenance
- • Estimating cooling or heating loads in the field
- • Consulting PT charts for R-454B, R-32, and R-410A refrigerants offline
Pricing: FieldCalc HVAC appears to operate on a freemium model, offering free access to basic PT charts and a one-time purchase option for full features at $9.99. There is no subscription, making it a cost-effective choice for HVAC professionals needing reliable offline tools.

Don't let your work go unnoticed. Get promoted!
Meridian is an open-source AI work journal designed to streamline daily work documentation without relying on cloud storage or accounts. Installed locally on your device, it automatically captures and summarizes your daily activities in plain English, providing a comprehensive overview of your work by the end of each day. Its seamless integration with project management tools like Jira allows users to generate draft updates that are ready for review and posting, saving time and reducing manual entry. Meridian is ideal for professionals who value privacy, control over their data, and efficient work tracking. Its open-source nature and offline functionality make it a unique choice for developers, remote workers, and teams seeking a secure, customizable tool that enhances productivity without external dependencies.
Pros
- Local, offline operation ensures complete data privacy and security
- Automatic daily summaries save time and improve work recall
- Integrates smoothly with project management tools like Jira
- Open-source and MIT-licensed, offering customization and transparency
- No account or cloud setup required, simplifying onboarding
Cons
- Limited to users comfortable with open-source and local software
- May require technical knowledge to customize or troubleshoot
- No commercial support or dedicated customer service
Best for
- • Daily work logging for remote software developers
- • Automated project updates for project managers
- • Personal productivity tracking and reflection
- • Secure, private work journaling for sensitive projects
Pricing: Free and open-source software, with no cost for download or use. Users may incur costs if they choose to customize or host locally, but there are no subscription fees or paid plans.