Beyond the "Rule of Thumb"
Why simplified estimates fail, and how our physics-based engine calculates the real load.
The Core Formula
Unlike other calculators that just multiply your square footage by a random number, we calculate the actual Heat Transfer Rate. This is the simplified version of the engineering standard known as ACCA Manual J.
1Delta T (ΔT)
The most critical factor. We pull the ASHRAE 1% Summer Design Temperature for your specific Zip Code. A home in Phoenix (108°F) has a much higher ΔT than a home in San Diego (82°F), drastically changing the load.
2U-Value
This represents your home's insulation efficiency. Instead of just asking for "Year Built," we now allow you to specify insulation quality to adjust the thermal conductivity of your walls and attic.
3Solar Gain
West-facing windows can admit 3x more heat than North-facing ones. Our new algorithm accounts for window orientation and glass type (Single vs. Double Pane) to calculate radiant heat gain.
New: Humidity (Latent Load) Factor
Air conditioners don't just cool air; they remove moisture. In humid climates like Florida or Houston, up to 30% of your AC's capacity is used just to dehumidify the air (Latent Load). Our calculator now automatically applies a humidity modifier based on your climate zone data.