Horsepower-hour and Heat unit

Horsepower-hour noun - A unit of work equal to the work done by one horsepower in one hour.

Heat unit and horsepower-hour are semantically related. In some cases you can use "Heat unit" instead a noun phrase "Horsepower-hour".

Heat unit noun - A unit of measurement for work.

Horsepower-hour and heat unit are semantically related. Sometimes you can replace phrase "Horsepower-hour" with "Heat unit", this phrases are similar.