Multi-tank water heater systems
A water heater system including two or more water storage tanks plumbed in series, parallel or a combination thereof and methods of controlling said water heater systems. The water heater systems may include one or more mixing valves and one or more temperature sensors for providing water at a desired temperature.
1. A water heater system for providing heated water to a hot water supply line of a building that distributes the heated water throughout the building, the water heater system comprising:
a first water storage tank having a first water inlet and a first water outlet, the first water storage tank controlled to a first setpoint temperature;
a second water storage tank having a second water inlet and a second water outlet, the second water storage tank controlled to a second setpoint temperature;
a water line fluidly connecting the first water outlet to the second water inlet for transporting water from the first water storage tank to the second water storage tank;
a mixing valve having a first inlet fluidly coupled to the second water outlet downstream of the second water storage tank, the mixing valve being controllable via a communications interface;
a cold water supply line in fluid communication with a second inlet of the mixing valve;
a mixed water outlet fluidly coupled to an outlet of the mixing valve, the mixed water outlet configured to be plumbed to the hot water supply line of the building;
a controller for controlling the mixing valve via the communications interface;
wherein the controller is further configured to monitor hot water usage from the second water storage tank to develop a hot water usage schedule of expected hot water demand; and
wherein the controller is further configured to adjust the first setpoint temperature of the first water storage tank in accordance with the hot water usage schedule.
2. The water heater system of claim 1 , further comprising a temperature sensor positioned in the mixed water outlet and in communication with the controller.
3. The water heater system of claim 2 , wherein the controller is configured to adjust a ratio of cold water entering the mixing valve from the cold water supply line to heated water entering the mixing valve from the second water outlet to achieve a desired temperature at the mixed water outlet.
4. The water heater system of claim 3 , wherein the controller is configured to adjust the ratio of cold water entering the mixing valve from the cold water supply line to heated water entering the mixing valve from the second water outlet based on feedback received from the temperature sensor.
5. The water heater system of claim 1 , wherein the first setpoint temperature of the first water storage tank is lower than the second setpoint temperature of the second water storage tank, and the second setpoint temperature of the second water storage tank is greater than a desired outlet water temperature of the water heater system.
6. The water heater system of claim 1 , further comprising a temperature sensor positioned in the cold water supply line and in communication with the controller.
7. A water heater system for providing heated water to a hot water supply line of a building that distributes the heated water throughout the building, the water heater system comprising:
a first water storage tank having a first water inlet and a first water outlet, the first water storage tank controlled to a first setpoint temperature;
a second water storage tank having a second water inlet and a second water outlet, the second water storage tank controlled to a second setpoint temperature;
a water line fluidly connecting the first water outlet to the second water inlet for transporting water from the first water storage tank to the second water storage tank;
a mixing valve having a first inlet fluidly coupled to the second water outlet downstream of the second water storage tank, the mixing valve being controllable via a communications interface;
a mixed water outlet fluidly coupled to an outlet of the mixing valve;
a controller for controlling the mixing valve via the communications interface; and
wherein the controller is further configured to store a hot water usage schedule of expected hot water demand, and to adjust the first setpoint temperature of the first water storage tank in accordance with the hot water usage schedule.
8. The water heater system of claim 7 , wherein the controller is further configured to adjust the second setpoint temperature of the second water storage tank in accordance with the hot water usage schedule.
9. The water heater system of claim 7 , wherein the controller is configured to monitor a hot water usage of the water heater system to develop the hot water usage schedule.
10. The water heater system of claim 7 , wherein the controller is configured to control a gas control unit of the first water storage tank in accordance with the first setpoint temperature.
11. The water heater system of claim 7 , wherein the controller is configured to control a gas control unit of the second water storage tank in accordance with the second setpoint temperature.
12. The water heater system of claim 7 , wherein the controller is configured to control a gas control unit of the first water storage tank in accordance with the first setpoint temperature, and to control a gas control unit of the second water storage tank in accordance with the second setpoint temperature.
13. The water heater system of claim 7 , further comprising a temperature sensor positioned in the mixed water outlet and in communication with the controller, and wherein the controller adjusts a ratio of cold water entering the mixing valve from a cold water supply line to heated water entering the mixing valve from the second water outlet to achieve a desired temperature at the mixed water outlet.
14. A water heater system for providing heated water to a hot water supply line of a building that distributes the heated water throughout the building, the water heater system comprising:
a first water storage tank having a first water inlet and a first water outlet, the first water storage tank controlled to a first setpoint temperature;
a second water storage tank having a second water inlet and a second water outlet, the second water storage tank controlled to a second setpoint temperature;
a water line fluidly connecting the first water outlet to the second water inlet for transporting water from the first water storage tank to the second water storage tank;
a mixing valve having a first inlet fluidly coupled to the second water outlet downstream of the second water storage tank;
a mixed water outlet fluidly coupled to an outlet of the mixing valve;
a controller configured to store a hot water usage schedule of expected hot water demand, and to adjust the first setpoint temperature of the first water storage tank in accordance with the hot water usage schedule.
15. The water heater system of claim 14 , wherein the controller is further configured to adjust the second setpoint temperature of the second water storage tank in accordance with the hot water usage schedule.
16. The water heater system of claim 14 , wherein the controller is configured to monitor a hot water usage of the water heater system to develop the hot water usage schedule.
17. The water heater system of claim 14 , wherein the controller is configured to control a gas control unit of the first water storage tank in accordance with the first setpoint temperature.
18. The water heater system of claim 14 , wherein the controller is configured to control a gas control unit of the second water storage tank in accordance with the second setpoint temperature.
19. The water heater system of claim 14 , wherein the controller is configured to control a gas control unit of the first water storage tank in accordance with the first setpoint temperature, and to control a gas control unit of the second water storage tank in accordance with the second setpoint temperature.
20. The water heater system of claim 14 , wherein the controller is further configured to control the mixing valve to achieve a desired water temperature at the mixed water outlet.