Plain-language meaning
BTU stands for British thermal unit. It is a unit of heat energy and is commonly used for heating, cooling and fuel comparisons.
Example
Air conditioners and heaters are often described in BTU per hour. About 3.412 BTU per hour equals 1 watt, so a 1,000 watt heating load is about 3,412 BTU per hour.
BTU vs BTU per hour
BTU is an amount of energy. BTU per hour is a rate of heat transfer or heating/cooling capacity. Many product labels use BTU/h even when they casually say BTU.
Limitations
Choosing HVAC equipment needs more than a unit conversion. Room size, insulation, climate, ceiling height, windows, air leakage and occupancy all affect the required capacity.
FAQ
Can BTU be converted to watts?
Yes. For power comparisons, BTU per hour can be converted to watts using a fixed conversion factor.
Is a larger BTU rating always better?
No. Oversized equipment can cycle inefficiently and may not control humidity well.