What is BTU per hour?
BTU per hour is a unit of power used to measure the heating or cooling capacity of HVAC equipment. It is the standard rating system for air conditioners, furnaces, and heat pumps in the United States.
Real-world uses
BTU per hour is the standard power unit for rating furnaces, air conditioners, heat pumps, and boilers in the United States. A residential central air conditioner might be rated at 24,000–60,000 BTU/h. In casual use, the "/h" is often dropped, so "12,000 BTU air conditioner" actually means 12,000 BTU/h.
History
BTU/h became the standard power unit for the US HVAC industry during the post-World War II residential building boom, as central air conditioning and forced-air heating became widespread. Industry standards bodies such as AHRI codified BTU/h ratings for equipment comparison.
Common mistakes
Dropping the "/h": confusing BTU (energy) with BTU/h (power) is extremely common in HVAC contexts. A unit absorbing 12,000 BTU in one hour is operating at 12,000 BTU/h of capacity. Also, 1 ton of refrigeration = 12,000 BTU/h, which can cause confusion in capacity comparisons.
What is microwatt?
A microwatt is a unit of power equal to one millionth of a watt. It is used in ultra-low-power electronics, energy harvesting systems, biosensors, and precision scientific instrumentation.
Real-world uses
Microwatts measure the power of radio frequency (RF) signals received by antennas, ultra-low-power IoT sensors, cardiac pacemaker power consumption, and energy-harvesting devices. Satellite receivers may work with signals in the nanowatt to microwatt range. Wearable health monitors often operate at a few microwatts.
History
Microwatts became a meaningful engineering unit as semiconductor miniaturisation through the 1970s–2000s enabled ultra-low-power circuit design. The proliferation of wireless sensors, implantable medical devices, and battery-free energy harvesting systems in the early 21st century made µW-level power budgeting essential.
Common mistakes
Confusing microwatts (µW) with milliwatts (mW)—a difference of 1,000×. In RF engineering, power is often expressed in dBm (decibels relative to 1 mW), which requires knowing that 0 dBm = 1 mW = 1,000 µW, and negative dBm values correspond to sub-milliwatt levels.
When is this conversion used?
Converting between BTU per hour and microwatt is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
Worked examples
1 BTU per hour = 293,071.07 microwatt
1 microwatt = 0.000001 watt
How to convert BTU per hour to microwatt
To convert BTU per hour to microwatt, multiply the value by 293,071.07.
To convert microwatt back to BTU per hour, multiply by 0.00000341.
Measurement standards
The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.
Did you know?
The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.
Quick reference: BTU per hour to microwatt
| BTU per hour | microwatt |
|---|---|
| 0.1 | 29,307.107 |
| 0.5 | 146,535.535 |
| 1 | 293,071.07 |
| 2 | 586,142.14 |
| 5 | 1,465,355.35 |
| 10 | 2,930,710.7 |
| 25 | 7,326,776.75 |
| 50 | 14,653,553.5 |
| 100 | 29,307,107 |
| 250 | 73,267,767.5 |
| 500 | 146,535,535 |
| 1,000 | 293,071,070 |
Common values
| BTU per hour | microwatt | |
|---|---|---|
| LED light bulb | 34.12141635 BTU per hour | 10,000,000 microwatt |
| Desktop computer | 1,023.64249054 BTU per hour | 300,000,000 microwatt |
| Microwave oven | 3,412.14163513 BTU per hour | 1.000000e+09 microwatt |
| Small car engine | 255,910.62263498 BTU per hour | 7.500000e+10 microwatt |
| Wind turbine (large) | 10,236,424.90539923 BTU per hour | 3.000000e+12 microwatt |
Available Power units
More BTU per hour conversions
- Convert BTU per hour to watt
- Convert BTU per hour to kilowatt
- Convert BTU per hour to horsepower (mechanical)
- Convert BTU per hour to megawatt
- Convert BTU per hour to gigawatt
- Convert BTU per hour to milliwatt
- Convert BTU per hour to microwatt
- Convert BTU per hour to kilocalorie per hour
- Convert BTU per hour to ton of refrigeration
Assumption: horsepower values use mechanical horsepower.