U-Value Calculator: Calculate Wall & Window Heat Loss (Free Tool) You are choosing insulation for a wall. You see R-19 on one product and U-0.05 on another. Which one is better? You cannot compare them directly because they measure different things. R‑value measures resistance to heat flow (bigger is better). … Read more
R-Value Converter: Compare Insulation & U-Values Instantly (Free Tool) You see “R-19” on a roll of insulation. The building code calls for “R-15” in the walls. But you are looking at a European window with a U‑value of 1.5 W/m²·K. How do you compare them? R‑value and U‑value are the … Read more
GPM to Tons Calculator: Convert Water Flow to Cooling Capacity (Free Tool) You are designing a chilled water system. You know the flow rate is 100 GPM. The temperature drop across the chiller is 10°F. How many tons of cooling capacity does that represent? In the HVAC industry, tons and … Read more
Exhaust Fan CFM Calculator: Size Your Ventilation System (Free Tool) You need an exhaust fan for your bathroom, kitchen, or workshop. You walk into the store and see fans with CFM ratings: 50 CFM, 110 CFM, 200 CFM. How do you know which one is right for your space? Buying … Read more
Humidity Ratio Calculator: Measure Moisture in Air (Free Tool) You walk into a building. It feels damp and clammy. You wonder: how much moisture is actually in the air? Relative humidity tells you a percentage. But it changes with temperature. A 50% RH room at 75°F has more moisture than … Read more
CO2 Ventilation Rate Calculator: Measure Your Indoor Air Quality (Free Tool) You walk into a meeting room. It feels stuffy. People are yawning. You wonder: is there enough fresh air? Carbon dioxide (CO2) is the best indicator of ventilation effectiveness. As people breathe, they exhale CO2. If the CO2 level … Read more
Room Ventilation Calculator: Design Healthier Indoor Spaces (Free Tool) You are designing a new classroom. You are setting up a home office. You are renovating a commercial kitchen. How much fresh air do you need? Ventilation is the process of bringing outdoor air into a building and distributing it throughout … Read more
Air Quality Index Calculator: Understand Your Air Quality (Free Tool) You check the weather app. You see a number like 85 or 150 next to “AQI.” What does it mean? Is it safe to go outside? Should you close your windows? The Air Quality Index (AQI) is the standard way … Read more
EER to SEER Calculator: Convert HVAC Efficiency Ratings (Free Tool) You are comparing air conditioners. One has an EER of 12. Another has a SEER of 18. Which is more efficient? You cannot compare them directly. EER and SEER measure efficiency under different conditions. EER is a snapshot at a … Read more
SEER2 Calculator (New 2023 Standard): Convert & Compare HVAC Efficiency (Free Tool) You are shopping for a new air conditioner or heat pump. You see “SEER2” on the label. But you remember “SEER” from before. What is the difference? How do they compare? On January 1, 2023, the U.S. Department … Read more
