Mr Kilowatt
How many kilowatts needed to heat water in water heater
Home
Search waterheatertimer.org / all results
Search using Find button  
 
Use 6 wraps teflon tape
? White for water lines
? Yellow for gas lines

Buy:
Teflon tape at Amazon

Buy:
Pipe wrench at Amazon
Channel locks

Resources:
How to remove rusted element


Buy:
Knipex channel locks
Irwin pliers
replace anode rod
Inspect anode each 2-5 years
Anode rod prevents tank from rusting
Buy:
Anode rods at Amazon

Resources:
Replace anode rod
How to maintain water heater

Buy:
Impact wrench at Amazon

Resources:
Replace anode rod
How to remove short water heater nipple
Water pressure gauge

Pressure gauge/ attach to water heater drain valve
Pressure over 80 psi can damage water heater and household plumbing
Buy:
Water pressure gauge
Temperature-pressure gauge

Resources:
Identify water heater valves
Troubleshoot water pressure
Automatic water heater shut off valve
Prevent flood
Automatic water shut off valve
Buy:
Water detectors at Amazon
Automatic water heater leak shut off at Amazon
Resources:
Leaking water heater/ steps
Pressure reducing valve
Pressure reducing valve
Pressure over 80 psi can damage water heater and household plumbing
Buy:
Pressure reducing valve

Resources:
Identify water heater valves
Troubleshoot water pressure
Sharkbite pressure gauge
Sharkbite pressure gauge

Buy:
Sharkbite pressure gauge

Resources:
Water heater valves

Water heater circulation system

Buy:
Grundfos at Amazon

Resources:
How to install recirculation system
COLD side Sharkbite flexible water heater connector
COLD side Sharkbite flexible water heater connector

Buy:
Sharkbite water heater connection
Braided water heater line
Stainless steel flexible connection

Resources:
How to install electric water heater
How to install gas water heater
Leaking water heater
HOT side Sharkbite flexible water heater connector
HOT side Sharkbite flexible water heater connector

Buy:
Sharkbite water heater connection
Braided water heater line
Stainless steel flexible connection
Braided water heater line
Flexible water heater connection

Resources:
How to install electric water heater
How to install gas water heater
Leaking water heater
89T thermostat kit
Electric water heater thermostats
Thermostats stick,& melt and come out of calibration... replace thermostat
Symptoms: Cold water, uneven temperatures, reset tripping, TP releasing water
Buy:
Water heater thermostats at Amazon

Resources:
How to replace electric water heater thermostat
Add another thermostat to water heater
How to wire thermostats
Marathon water heater thermostats
Two water heaters
Troubleshoot electric water heater
Icon gas valve   
Gas water heater thermostats
If tank is overheating or not heating correctly, replace thermostat
Symptoms: Cold water, uneven temperatures, TP releasing water
Buy:
Gas water heater thermostats at Amazon

Resources:
How to replace gas water heater thermostat
Add another thermostat to water heater
Troubleshoot gas water heater
Kilowatt hours of electricity needed to heat water ... the math formula:
1.) Basic formula > it takes .0002931 Kwh to raise 1 pound of water 1°F

2.) Basic number >A gallon of water weighs 8.34 lbs (pounds)

3.) "A BTU is amount of heat needed to raise 1 pound of liquid water by 1° from 60° to 61° F at constant pressure of one atmosphere. Other definitions of BTU exist which are based on different water temperatures and cause the results to vary by .5%." (For analysis of water heaters, .5% is ignored. Variation in atmospheric pressure is also ignored. Water heater 'science' is an approximation since calcium carbonate in tank will vary electrical efficiency and tank capacity.)
Formula for heating water inside tank:

4.) BTU formula > 1 BTU = 2.931 x 10–4 Kwh (kilowatt hours).
     BTU = 2.931 x .0001 = .0002931 Kwh
     Therefore it takes .000293 Kwh to raise 1 pound of water 1° F
 
5.) 30 Gallons of water x 8.34 = 250.2 lbs
     40 Gallons of water x 8.34 = 333.6 lbs

Calculation using 40 Gallon water heater:
> Ordinary 40 gallon water heater in attic. Temperature in attic = 50° F. Temperature of water in tank = 50° F.
> Water in tank weighs 333.6 lbs.
> How much electricity is needed to raise temperature of full tank to 120° F.
> 120° minus 50°  = 70° > so the temperature needs to go up 70°
> Multiply 333.6 x 70 x .0002931 = 6.84 Kwh

Calculation using 30 Gallon water heater:
> Same problem as above
> Water in tank weighs 220.2 lbs
> Multiply 250.2 x 70 x .0002931 = 5.13 Kwh
Formula for heating water inside tank:
The number of gallons of water that are heated Per Hour (for Electric heater) = (Kw rating of element x 3413) divided by (temperature rise x 8.34)
8.34 is weight of 1 gallon water. Resource: Water heater formulas and terminology .pdf

Calculation #1
Let's say you have 5500 watt elements which are 55 Kw.
Let's say incoming water temperature is 65°F and you want to heat tank to 105°, or 40° rise in temperature. (40 temp rise not shown on the AO Smith chart)

5500 watt or 5.5Kw elements x 3413 = 18771.5
40 degree temperature rise x 8.25 = 333.6
So 18771.5 divided by 330 =
So in this specific situation, the element would heat 56.26 gallons per hour

Calculation #2
If you have 4500 watt elements and incoming water temperature is 55°, and you want to heat to 120°, then the temperature rise is 65° (65 temp rise is not shown on chart)
4.5 KW x 3413 = 15358.5
65 degree temperature rise x 8.34 = 542.1
15358.5 divided by 536 = 28.
So one element would heat 28.33 gallons per hour.
Note: the chart shows 30.8 for 60° rise, so you would expect 65 rise in temperature would result in lower output than 60. This says that reasonable estimates can be made using the AO Smith chart.

Measuring water temperatures can be accomplished using a PID sensor taped to pipe and covered with insulation, or by installing temperature gauge on pipe, or bleed water out of TP valve and use cooking thermometer.
Buy:
Winters Temperature gauge
Temperature-pressure gauge for boiler
Pocket thermometer
Kitchen Thermometers
PID proportional integral device
Resource:
Control water heater with PID

Considerations
Calculations do NOT consider heat loss from tank, ambient room temperature, thickness of insulation, low voltage, approximate calibration of thermostats, and inefficiencies such as elements coated with sediment etc. There are too many variables to make any calculation exact, so all number for heating water are approximations which help determine actual performance vs potential problems with heater.
The number of gallons per hour is per EACH element, but remember, with residential simultaneous tank, only ONE element is ON at one time.
Upper element is ON, or lower element is ON, or BOTH elements are off. At no time are both elements on, unless heater is wired for simultaneous operation.
Resource:
How to wire simultaneous water heater thermostats
KW Required for water heater = (GPH gallon per hour x 8.25 x Temp. Rise x 1.0) divided by (3413)
One kilowatt is equal to 3,413 BTU

Volts x amps = watts
Watts x 1000 = Kilowatt (power)
Kilowatt is a static measure of power delivered to load
Kilowatt hour (Kwh) is a dynamic measure of billable power usage for 1 hour of load operation

0.0002931 Kwh to raise 1 pound of water 1°F
0.0024444 Kwh to raise 1 gallon of water 1°F
0.146666  Kwh to raise 1 gallon of water 60°F (60-120°F)
5.866689  Kwh to raise 40 gallons of water 60°F (60-120°F)
1 Kw = 3413 BTU
2.42 watt required to raise 1 gallon water 1 degree
1 Kwh will raise 6.8 gallon water 60 degrees F
8.33 BTU will raise 1 gallon of water 1 degree at 100% efficiency
11 BTU required to raise 1 gallon of water 1 degree at 75% efficiency (gas)
1 cubic foot natural gas = 1000 BTU
1 therm 100,000 BTU or 100 cubic feet
1 cubic foor propane = 2500 BTU
1 gallon propane = 91,250 BTU
More formulas

Water heater formulas and terminology/ pdf
Electrical formulas /pdf
water consumption bathtub
Take showers instead of bath.
Regular bath uses 13- 17 gallons hot water (20 gal water total)
Set water heater timer for 45-60 minutes for hot bath

Shower uses 6 - 8 gallons of hot water (10 gal water total)
Set water heater timer for 20-30 minutes for hot shower


Resources:
How much hot water for bath or shower
Compare water heater timers
Off peak water heater options

Buy:
Bathtubs and shower stalls at Amazon
Shower stalls at Amazon
Home energy savings books at Amazon
Cost for 1 bath
15 gallons hot for bath x 8.34 llb per gallon x 60 degree rise in temperature x .14 cets per kwh = 1050
 3413 BTU content of fuel x .95 efficiency rating of heater = 3139
1050 divided by 3193
= 33¢ cost of hot water per bath inside standard 15' x 30" x 60" Princeton bathtub.

9 gallon shower cost 19.8¢
Temperature of water
Cost if you use 40 Gallon per day Cost if you use 30 Gallon per day
Raise from 32° to 120° 8.60 Kwh x 14¢ = $1.20 6.45 Kwh x 14¢ = 90¢
Raise from 50° to 120° 6.84 Kwh x 14¢ = 96¢ 5.13 Kwh x 14¢ = 72¢
Raise from 70° to 120°> 4.88 Kwh x 14¢ = 68¢ 3.66 Kwh x 14¢ = 51¢
Raise from 85° to 120° 3.42 Kwh x 14¢ = 48¢ 2.56 Kwh x 14¢ = 36¢

See Family chart for setting water heater timer
Resources:
Calculate first hour delivery
Calculate recovery

Batch solar water heater uses no electricity

Resource
Batch solar water heater
Closed loop system recirculates solar-heated water
Consumes various amounts of electricity depending on conditions, location etc.
This type system does extremely well in naturally warm environments such as Hawaii.

Resource
Ask questions before buying closed loop
Photovoltaic water heater Do it yourself PV solar panel
This is best option for lowering electric bill and supplying hot water

Resources
Convert AC water heater to DC/ high voltage
Convert AC water heater to DC/ low voltage
Install meter on electric water heater
Fuse on power pole Price of water

No water/ no electricity/

Read about electric generation/ What is 3-phase electricity
Support the economy:
Buy water heaters from my associate links:

50 gallon Gas water heaters at Amazon
40 gallon gas water heaters at Amazon
50 gallon Electric water heaters at Amazon
40 gallon electric water heaters at Amazon
Hybrid / heat pump/ water heaters at Amazon

Resources:
How to install gas water heater
How to install electric water heater
Troubleshoot gas water heater
Troubleshoot electric water heater
Point of use water heaters
Resources:
Troubleshoot Gas valves with manuals
Icon gas valve

How to replace water heater element Waste King disposal
How to wire tankless electric

How to install tankless recirculation


Install point of use water heater
Titan tankless

Contactors/ relays
Install and troubleshoot garbage disposal Waste King disposal
Programmable timers

Woods timers
surge protection
Anode rods anode rods
Recirculation system

Tankless recirculation
Point of use water heater
Type 1 and type 2 surge protection surge protection
Buy
Electronic parts

Industrial supplies

Tools and home improvement

Home and garden

Hayward pool
Pentair pool

Southwire electric
Buy
Tools

DEWALT
Black and Decker
Stanley
SKIL
Makita
Porter-Cable
Bosch

Irwin Hand tools
Klein hand tools
Fluke electrical testing
Dremel hobby tools

Campbell Hausfeld air powered
Tekton automotive

Powerbuilt automotive
Saws and saw blades
box timers Resource:
Compare box timers
DPDT timers
Intermatic
Control water heater w/ Z-wave
Intermatic control centers Resource:
Intermatic control centers: and parts
Digital control centers and parts
Tork control centers and parts
Subpanels
All control centers and parts
Enclosures
programmable timer Resource:
Programmable timers
Countdown timers
Off delay timers
On delay timers
Timer modules
Din rail
Twin & one-shot
Woods
Intermatic
Tork
Low voltage power packs Recirculation systems
Enter Amazon from my links
Amazon

E-mail: geno03245w@gmail.com
My response might end up in spam folder, check email folders
Waterheatertimer on Twitter