The key components of a conventional well system consist of a jet or submersible well pump, a pressure tank, and a pressure switch.
A submersible well pump is located down the well, typically 20 feet off the bottom. It must be sized appropriately for the well, taking into consideration the yield of the well and the depth at which the water level is while being pumped. An oversized pump may have a short life, while an undersized pump may not supply enough water.
The pressure switch allows the well pump to turn on and off as the pressure tank is filled and drained. It turns on at a lower pressure and shuts off at a higher pressure. Without this, the pump would never shut off potentially causing catastrophic failure of numerous components.
The tank must be sized correctly to allow the pump adequate runtime to provide proper cooling to the motor. The pressure tank is comprised of approximately 70% air. This captive air is what allows the bladder to expand as the well pump fills the tank. When the tanks bladder is compromised, the air is exchanged with water and the bladder can not expand fully. This results in shorter run times and shortens the life of the pump.
A constant pressure system, otherwise known as a variable speed well system, consists of the same components as a conventional system with a twist. Rather than relying on a simple pressure switch to turn the pump on or off, they use a sensor and control box to control not just when the pump should turn on or off, but how fast it should run to maintain the desired water pressure. This means the pump will run slower and produce less water when a toilet is flushed, compared to filling a bath.
The brains of the system. It is responsible for controlling the well pump speed as well as protecting it from avoidable damages. Most controllers are equipped with some form of the following:
The sensor is the eye of the control box. It relays the current water pressure reading to the control box indicating if the pump needs to speed up or slow down.
The bladder tank typically used in constant pressure applications is much smaller than that of a conventional system, it even mounts to the wall! Without needing to worry about volume, the tank is only used as a buffer for the well pump to help maintain water pressure.
A storage system combines a conventional and constant pressure system while harvesting hundreds of gallons of water for reserve.
The storage tank housing your reserve is filled by your existing conventional system. A float controls when the tank is filled and to what depth.
A variable speed pump draws water from the tank to feed the house. Similar to how a constant pressure system operates.