Home Energy

Estimate room AC size in BTU per hour from square feet, ceiling height, sun, people, kitchen heat, insulation, and summer heat.

Estimate cooling load and a nominal mini-split size for one room or open zone using area, ceiling height, sun, and room use.

Estimate furnace BTU/h input size from home area, climate, insulation, AFUE, model sizes, and an optional quote comparison.

Calculate room AC capacity by area and conditions, or convert a documented whole-home cooling load into BTU/hr and tons.

Estimate home heating load, cooling load, AC tons, airflow, and standard AC size from simple home details.

Calculate heat pump COP from heat output and electric power, plus optional gas break-even and Carnot temperature checks.

Estimate whole house fan CFM, attic net free vent area needed, vent gap, and the largest fan your vents can support.

Estimate ceiling fan cost per day, running month, and year using fan watts or an EnergyGuide yearly cost label.

Estimate furnace fuel cost by BTU rating, efficiency, run time, fuel price, and optional blower electricity.

Estimate space heater running cost from watts, hours, days, electricity rate, heater count, thermostat on-time, and months used.