About BTU Planner

BTU Planner answers the sizing questions that come up when you replace an air conditioner, add a room, or finally insulate the attic. How many BTU does this room need? Is the 4-ton unit in this quote too big? Will an 8-inch duct carry the air? How thick is R-49?

Each tool shows its formula, the table it uses and where that table came from, so you can check the result instead of trusting a black box. Where we had to make a modeling choice, such as how much heat an "average" house loses per degree, the page says so and the methodology shows the arithmetic.

Who builds it

The site is written and maintained by Nikita Klesh, who studied at the Kyiv Civil Engineering Institute (KISI), today's Kyiv National University of Construction and Architecture. Building physics (heat flow through walls, insulation and ventilation) is part of a civil engineering education. This site applies it to US houses, US codes and US units.

What we will not do

• We do not sell equipment or take referral fees from installers. A tool here never pushes you toward a bigger unit.
• We do not invent precision. A square-foot method stays an estimate, and every calculator says so next to the result.
• We do not copy other sites' charts. Tables are built from primary sources (ENERGY STAR, ASHRAE, the IECC) or computed by our own code.

Advertising

The site may show ads in the future to pay for itself. Ads will not change any number a calculator gives you.

Questions or corrections: [email protected].