Method for operating a water heater appliance
A method for operating a water heater appliance is provided. The method includes establishing a temperature drop of water within a tank of the water heater appliance during a time interval. A volume of heated water within the tank is estimated based at least in part on the temperature drop of water within the tank of the water heater appliance during the time interval and a set temperature of the water heater appliance. A related water heater appliance is also provided.
1. A method for operating a water heater appliance comprising a tank and a heating element to heat water within the tank, the method comprising:
measuring a temperature of water within the tank of the water heater appliance at a first time during a time interval;
measuring the temperature of water within the tank of the water heater appliance at a second time during the time interval;
establishing a temperature drop of water within the tank of the water heater appliance during the time interval, the step of establishing a temperature drop comprising
calculating a difference between the temperature of water within the tank of the water heater appliance at the first time and the temperature of water within the tank of the water heater appliance at the second time, and
comparing the difference in temperatures to one or more functions of a set temperature, t s , the set temperature t s of the water heater appliance being greater than one hundred and twenty degrees Fahrenheit;
estimating that the volume of heated water within the tank is half a volume of the tank if the temperature drop of water within the tank of the water heater appliance from said step of establishing is greater than a first function of the set temperature t s of the water heater appliance, and
estimating that the volume of heated water within the tank is one-quarter of the volume of the tank if the temperature drop of water within the tank of the water heater appliance from said step of establishing is greater than a second function of the set temperature t s of the water heater appliance; and
activating the heating element to heat water within the tank based on the estimated volume of heated water.
2. The method of claim 1 , wherein said step of measuring comprises measuring the temperature of water within the tank of the water heater appliance with a temperature sensor of the water heater appliance, wherein said step of gauging comprises gauging the temperature of water within the tank of the water heater appliance with the temperature sensor of the water heater appliance.
3. The method of claim 1 , wherein a temperature sensor of the water heater appliance is positioned at a top portion of the tank of the water heater appliance.
4. The method of claim 1 , wherein the first function of the set temperature it of the water heater appliance comprises
F
1
(
t
s
)
=
6
+
4
15
(
t
s
-
120
)
or
F
1
(
t
s
)
=
7
+
1
3
(
t
s
-
120
)
.
5. The method of claim 4 , wherein the second function of the set temperature t s of the water heater appliance comprises
F
2
(
t
s
)
=
10
+
1
3
(
t
s
-
120
)
.
6. The method of claim 1 , wherein the first function of the set temperature t s of the water heater appliance comprises
F
1
(
t
s
)
=
3
+
1
15
(
t
s
-
120
)
.
7. The method of claim 4 , wherein the second function of the set temperature t s of the water heater appliance comprises
F
2
(
t
s
)
=
10
+
7
15
(
t
s
-
120
)
.
8. The method of claim 1 , wherein the time interval is an hour.
9. A water heater appliance, comprising:
a tank defining an interior volume;
means for heating water within the interior volume of the tank to a set temperature, t s ;
a temperature sensor positioned adjacent a top portion of the tank and configured for measuring a temperature of water within the interior volume of the tank;
a controller in communication with the temperature sensor and the means for heating water, the controller configured for
measuring the temperature of water within interior volume of the tank with the temperature sensor at a first time during a time interval;
measuring the temperature of water within interior volume of the tank with the temperature sensor at a second time during the time interval;
establishing a temperature drop of water within the interior volume of the tank during the time interval, the step of establishing a temperature drop comprising
calculating a difference between the temperature of water within the tank of the water heater appliance at the first time and the temperature of water within the tank of the water heater appliance at the second time, and
comparing the difference in temperatures to one or more functions of a set temperature, t s , the set temperature t s of the water heater appliance being greater than one hundred and twenty degrees Fahrenheit;
estimating that the volume of heated water within the tank is half a volume of the tank if the temperature drop of water within the tank of the water heater appliance from said step of establishing is greater than a first function of the set temperature t s of the water heater appliance, and
estimating that the volume of heated water within the tank is one-quarter of the volume of the tank if the temperature drop of water within the tank of the water heater appliance from said step of establishing is greater than a second function of the set temperature t s of the water heater appliance; and
activating the means for heating water based on the estimated volume of heated water.
10. The water heater appliance of claim 9 , wherein the temperature sensor is mounted to the tank at a top portion of the tank.
11. The water heater appliance of claim 9 , wherein said step of establishing comprises calculating a difference between the temperature of water within the tank of the water heater appliance at the first time and the temperature of water within the tank of the water heater appliance at the second time.
12. The water heater appliance of claim 9 , wherein the first function of the set temperature t s comprises
F
1
(
t
s
)
=
6
+
4
15
(
t
s
-
120
)
or
F
1
(
t
s
)
=
7
+
1
3
(
t
s
-
120
)
.
13. The water heater appliance of claim 9 , wherein the second function of the set temperature t s comprises
F
2
(
t
s
)
=
10
+
1
3
(
t
s
-
120
)
.
14. The water heater appliance of claim 9 , wherein the first function of the set temperature t s comprises
F
1
(
t
s
)
=
3
+
1
15
(
t
s
-
120
)
.
15. The water heater appliance of claim 9 , wherein the second function of the set temperature t s comprises
F
2
(
t
s
)
=
10
+
7
15
(
t
s
-
120
)
.
16. The water heater appliance of claim 9 , wherein the time interval is about an hour.