Sir John Harington, a godson to Queen Elizabeth, invented the first water closet in 1596. He was largely ridiculed for the device, which was not reinvented again until Alexander Cummings perfected the device and added the first sliding valve for waste elimination.
The washdown water closet is the least expensive among the three types of residential water closets. The trapway is relatively small and at the front of the bowl. This unit is a little less effective than the other water closets.
The trapway for the reverse-trap water closet is at the back. This type of water closet tends to be quieter than the washdown version. Siphon jet water closets, the most common type, discharge water from the flushing rim and pull the contents down by centrifugal force.
A person may consider using a blowout water closet, which is mainly used commercially in airports, hospitals and schools. This unit will need to be installed in the wall as it does not contain a water tank.
A person must allow enough space for a water closet, so it is important to obtain the footprint and right dimensions of the water closet before installation. If someone changes from one type of water closet to another, he will also need to change the outlet pipe and closet bend.