Let's say your trusty old furnace is at the end of its life. You've got to buy a new one, so you call your HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. company and they rush over to make sure you don't freeze during the next cold snap. They go and take a look at your furnace and find its capacity. They come back and tell you that you have a furnace rated for 60,000 BTUBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules.
per hour and then talk to you about some of the options.