In very cold countries heating the home is a common practice. Man has used several methods to keep himself warm. Fire was lit and people gathered around it for warmth. Later fire places were built in homes were logs of wood was burnt to keep the whole room warm later hot water was circulated in metal pipes which had to be stopped because of corrosion and toxicity of the metal. A new method was devices with the advent of PEX material. These pipes are laid under the floor and heated water is passed through them. Lot of thought went into optimizing the system when the use of manifold was realized.
Manifold is a short piece of pipe of one inch diameter. It is made of copper. It has some side outlets with valves on them to which PEX pipes are attached. As the manifold is an open ended one it has a 3/4" inlet as well as outlet. PEX manifold w/ valves - open ends has outlets on the side which are of 1/2" The valves fitted to them are mechanical device which can be operated by turning the handle to close or open valve. The basic purpose of a valve is having control on the flow of the fluid or gas in it.
The valves of the manifold used in the radiant heating system are useful to control the flow of hot water. Manifolds come with multiple side outlet choices and all the outlets are evenly placed. The standard distance between two outlets is two inches. The length of the copper pipe is determined by the number of outlets it has. There are manifolds with four, five or six out lets. As the distance between two outlets is fixed it is easy to calculate the number of manifolds that would be required to lay the under floor pipes.
PEX manifolds w/ valves - open ends is device which has many advantages. Every line can be marked so that it becomes easier to control the flow of water to areas where it is not required. Rooms which are not occupied need not be heated. Water supply to those rooms can be suspended by turning off the valve.
Whenever a pipe has to be replaced or repaired water need not be stopped for the whole room, valve of that particular pipe can be closed so that the repair can be carried on. The very next pipe can have the water flowing through it. Combinations of manifolds are used to lay a floor heating system.