The heat capacity is largely constant in the temperature range that the calculators work (34-210°F or 1-99°C). We normally see energy in our electricity meter and bill as kilo-watt hours, rather than kilo-joules, so we have to divide by 3,600 (the number of seconds in an hour) to convert them — so 18,900 KiloJoules is 5.25 kilowatt-hours (18900 ÷ 3600 = 5.25) So basically I use 5.25 electricity credits every day heating up water. But I have an idea. For practical purposes, it should be precise enough. Let’s make a calculation example for a tub with 250 us gallons that cools down from 105f to 103f in 2 hours. I am tasked to maintain a 110L aquarium at 22-24C outdoors in Texas. how to calculate power required to heat water. For an electrical heater that can be a good assumption, but not for a gas heater. However, oil needs a much lower watts density element than water, as described in the “How to choose an oil heater” article. One Btu is 0.000293 kWh. Thermal radiation losses are responsible for 20%-30% of heat energy loss in the swimming pool. Also we can use this information to extrapolate both ways. Energy rates as of November 1, 2020. 1) thermal transfer from heat source to water 2) As the water is heating up, the loss of water temperature due to conduction to the cooler surrounding air. Start temp as final and end temp as start. I'm heating a liter of water from 25C to 60C. How do I calculate btu size for heating a swimming pool? Since water gets lighter when heated it will start to ascend around the coil and cold water will flow to the coil from below. EDIT: My gas is billed in 15kg gas cylinders, but feel free to allow for liters of gas. When using a simple coil submerged in water, then it will start to heat the water just around it. The power in watts is then found by: energy (joules) / time (seconds) To convert that answer to kilowatts, divide by 1000. This calculator tells you how long it takes to heat water from start to end temperature with a given heating power. There are others who need guidance and advice as to what they need. One kilo calorie is the amount of heat needed to raise the temp. heat of vaporization of water is 2256 kJ/kg. Converesely, if we only use half the heating power, 1.75kW, it will take twice as long to heat up to desired temperature, ie, 2 hours. Only input whole numbers, do not use a comma or point. This is for a hot tub, I do not need to increase or decrease the temperature. The mass of the one liter of H2 produced by a typical "HHO" scam device in one minute: .000089 kg = .089 grams = 89 milligrams. 1758120 kilojoule/hour = 488.36666667 kilowatt hour To heat the water to boiling: E = 4.186 kJ/kgC x 0.998 kg x 76C = 317.5 kJ = 0.088 kW-hr. How long would it take a kettle with a 1kW heating element to heat 1 litre of water? Water Litre to kg: 1 Litre = 0.999975 kg, so for all practical purposes 1 L = 1 kg Water kg to Litre: 1 kg = 1 litre Example: LPG Gas 14.2 kg Equals How Many Liters with 75% Butane For LPG (propane) 1 kg = 1.96 L. Therefore, 14.2 kg = 27.832 L. For LPG (butane) 1 kg = 1.724 L. Therefore, 14.2 kg = 24.48 L 1 kilowatt hour (kWh) = 3.6 megajoules 1 megawatt hour (MWh) = 3.6 gigajoules 1 kJ = 0.278 Wh 1 MJ = 0.278 kWh 1 GJ = 278 kWh 1 TJ = 278 MWh 1 PJ = 278 GWh 1 kWh = 3.60 MJ 1 calorie (c) = 4.19002 Joules Note 1 calorie is (approximately) the amount of heat required to raise the temperature of one ml of water by 1 degree Celsius. According to "latent heat of vaporization of water" it would take around 0.62 kWh/liter but I'm not sure...please help! Please remember, that the calculators above assume 100% conversion efficiency. Cost To Heat Water Using Electricity A typical electric water heater is 90.4 to 95% efficient or 92.7% average efficiency. Where C p is the heat capacity of water (1 BTU/lb/F) and m is the mass of the water (Assume 1 gal has 8.3 lb of water and the 3,412 BTU = 1 kWh) Solution: Energy required for heating the water to 120°F: = m × C p × ΔT = 100 gal day × 8.3 lb gal ︸ m × 1 BTU lb °F ︸ C p × (120 − 65) °F ︸ ΔT = 100 gal day × 8.3 lb gal × 1 … 98°C to 102°C) this does not hold true any more. Posted on March 13th, 2016
Hence, the energy needed is 34/3.6 = 9.5 kWh. Heating water to have a bath can be a major cost on your energy bills depending on how you heat the water and how much water you use. … There are those who tell us what they want as they know their exact requirements. I’m trying to figure out what would it take to heat my pool using a heating pipe after the filtration pump. Example - Batch Heating with Steam . of 1kg water by 1˚C . For rocket science one might want to calcualte it more accurately. Think of power as the rate at which energy is used. Boil or evaporate? If i change the power to 1.6kw . Also, you should have some extra power available, just to be sure. 3412 BTU = 1 kWh. Often, energy is measured in kWhs The calculators support Celcius/Centigrade, Fahrenheit, Watts (w), Kilowatts (Kw), Btuh, Joule, British termal unit (Btu), liter, gallon, kg, lb, cubic inch, cubic foot etc. The increase in temperature is 45 Kelvin (60-15) So the energy needed is 180,000 x 45 x 4.2 = 34MJ. -2°C to + 2°C) or from fluid to gas (e.g. Running a bath will use approximately 60 - 80 litres of water. Last edited: Jun 16, 2016. C p is the specific heat of water (4.186 J/gm deg C) The calculator below can be used to determine the temperature delta or rise for a given cooling water application (heat load or power dissipated and cooling water flow rate) using the first formula above. specific heat of ice is 2.06 kJ/kgC. It very much depends on the surrounding temperature, the heat conductivity of your hot tub material, and the shape of the tub. What formula did you use to calculate the water heating power? Create a free website or blog at WordPress.com. It takes 667 92.7% = 720 Btu’s to heat a gallon of water using electricity. 1 to heath one liter of water it will cost one kcal, what equals 4.18 kJ. For less than the price of a new heater tank, I now have free hot water. it takes the same amount of energy to heat water from 48 degrees to 52 degrees as it takes to heat water from 58 degrees to 62. Your calculators are a big help in figuring the size of the heat sump. annual and total lifetime water heating costs based on different water heating systems and energy sources. One question which comes up time and again is “How many kW do I need to heat up my tank?”. Nice calculator buttt…… you’ve got the abbreviations for the metric units incorrect. Heating a full 184 litre (40g) tank costs $1.33 and $2.01 for a 279 litre (60g) tank. So we've got 0.166 kWh to heat a gallon of water, or 0.166 x 40 = 6.63 kWh to heat a 40-gallon tank. of 1g water by 1˚C . I am assuming calculations take into account the specific heat capacity of water? Hi, I am trying to calculate the energy required to heat air that is 6.7 degrees C to 21 degrees C, in kilowatt hours, and for a range of other temperatures (5.7, 6.9, 9.5..... and many others, all to 21 degrees celsius/centigrade). Water is heated to 90oC. Also we can use this information to extrapolate both ways. Solve for Thermal Power I have saved the page to my home screen. meaning that the water would be heated in 1 hour by 3.5kW of applied heat. 488 kwh for 1 hour • The heat content of one gallon of fuel oil roughly equals that of 41 kWh of electricity, 137 cubic feet of natural gas, 1.5 gallons of propane, 17.5 pounds of air-dried wood, 17 pounds of pellets, a gallon of kerosene, or 10 pounds of coal. The amount of energy needed to raise the temperature of 1 g of water by 1 degree Celcius or (1 Kelvin) equals 1 calorie. 100 kcal of heat is required to raise the temp of 1 kg water from 0 ˚C to 100 ˚C. Cost To Heat Water Using Electricity A typical electric water heater is 90.4 to 95% efficient or 92.7% average efficiency. This unit is less used than it was. The calculators assume 100% efficiency and no loss of energy during the heating process. The calculators cannot deal with dots or comma. Appreciate the calculators but i was wondering if you could tell me the exact equations used for the “Water Heating Energy Calculator” or give some sort of excel sheet to double check it. 1 L water = 0.998 kg. At $0.30/kWh that's $2.85. This is also The value of the specefic heat of water. ( Log Out / Last updated on April 16th, 2020. is there a formula to calculate the temperature required for 5 gallons of water that will increase the temperature of a stainless steel 15.5 gallon tank from 46F to 161F. This means that you will have to pay 23 €ct to heat the bathwater with electricity and and 12 €ct to heath with gas if you take a bath (exlusive watercosts). Heating water to have a bath can be a major cost on your energy bills depending on how you heat the water and how much water you use. An I missing something here? All help is greatly appreciated - where possible, assume 'normal' conditions, i.e., use a standard or generally accepted density for air. That is a 1 ATM. 1 meter cube = 1000 Ltrs Thats $0.01275 per gallon for gas and $0.01825 per gallon with electric. I just recently learned about hybrid heat pump water heaters for the home that have much higher heating efficiency than standard electric. As 1 litre of water needs about 1.16 watts to raise it through 1°C in an hour, a 120 litre tank of cold mains water needs a total energy input of about 7800 watts-hours (120*1.16*56) to raise its temperature to the required level. , As another calculator for us math dummies could be total kw x cost of electrical supply. The higher element usually is for when you need to heat some water in middle of day. Heating oil provides 138,500 British thermal units (BTU) per US gallon; 1 BTU = 0.000293 kWh; 1 US gallon = 3.78541178 litres (138,500 * 0.000293)kWh in 3.78541178 litres (138,500 * 0.000293)/3.78541178 kWh/litre = 10.720233982047786621512547837002 Volume of fluid to heat in litres: Starting temperature degrees C: Target temperature (finishing) degrees C: Heating power kW: Density of water kg/dm 3: 1. time required to reach target temperature at given power: hours that is impossible to calculate with the information given. This is the best set of calculators on the internet . The calculators use the specific heat capacity of water of 4186 J/kg/°C (Joules per kilogram per degree Celsius). Also we can use this information to extrapolate both ways. It is the way it is taught at school. So 78 C rise requires 326,508 Joules per kg. Density: 1000 kg / m 3 or 1 kg / litre This is a measure of the mass (weight) of a set volume of water. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Pt is the power used to heat the water, in kWh. 1kcal=1000cal. 1 C. colshaws. ( Log Out / P = calculated heat transfer (kW) h e = evaporation energy of the steam (kJ/kg) The evaporation energy at different steam pressures can be found in the Steam Table with SI Units or in the Steam Table with Imperial Units. density of water is 1g/cu.cm or 1kg/cu.d. If you have problems with the units, feel free to use our temperature conversion or weight conversion calculators. So one Btu is 0.00001 therms. A BTU is the amount of energy required to heat 1 pound of water by 1°F (specifically from 39° to 40°F). For 8 hours 488/8 = 61kw. Hot water cylinders/tanks come in many shapes, sizes and capacities, ranging from 40 to over 400+ litres in larger homes. Thanks! The insulation of where the heating device sits and whether any heat can escape into something other than the water (like a wall, concrete etc.) Irvine) Heating a gallon of water by 1°F with no losses thus takes 8.33 ÷ 100,000 = 0.00008.33 therms. A typical electric water heater is 90.4 to 95% efficient. This is great. While this appears to be a conservative estimate of water-related energy use, our findings suggest that the carbon footprint currently associated with moving, treating and heating water in the U.S. is at least 290 million The heat capacity Cp of water is 4.186kJ/kg-C That means that for every 10 litres of hot water you use will only cost you 7 cents. I am wondering though, doesn’t heat capacity increase with temperature, potentially throwing off the calculation? To heat 1 ml of water takes 4.18 Joules per degree C, the specific heat capacity. For Heating Water in Tanks: KW = Liters x Temperature Rise (°C) 790 x Heat-up Time (hrs.) To determine BTU lost can I use the “Water Heating Energy Calculator” only backwards? It also should be noted that the difference between the starting temperature and the desired final application temperature is commonly referred to as delta T (ΔT). 1 Watt = 1 Joule of energy per second 1 kW = 1000 Joules of energy per second. One therm is 100,000 btu's. At $0.11/kWh, it costs 6.63 x $0.11 = $0.73 to heat a 40-gallon tank." There's a great answer about heating water with electricity, where anyone can easily get an idea how much would it cost to heat water just by applying one's price for kWh. The two keys they had were that it cost $0.51 to heat 40 gallons using gas or $0.73 using electric. The gas needed depends on your boiler, it's perhaps 60% efficient. Lecci is about 10p / kWh, so about 50p for a bath and 10p for a litre of tea. heat of fusion of ice is 334 kJ/kg. Thank you! For 4 hours 488/4 = 122kw Volume of fluid to heat in litres: Starting temperature degrees C: Target temperature (finishing) degrees C: Heating power kW: Density of water kg/dm 3: 1. time required to reach target temperature at given power: hours Great calculator. for example 100 litres of water, to be heated from 20 ºC to 50 ºC, giving a temperature rise of 30 ºC would give – 100 x 4 x 30 / 3412 = 3.52 meaning that the water would be heated in 1 hour by 3.5kW of applied heat. It would be more complicated to build calculators that can handle that and I have not done so. Hi all. E = (4.2 kJ/kgoC) ( (90 oC) - (20 oC)) (1000 liter) (1 kg/liter) = 294000 kJ. Specific heat capacity of water kcal/kgx°C 3: 1. 180 litres of water is near enough 180kg. meaning that the water would be heated in 1 hour by 3.5kW of applied heat. One kWh is 3413 Btu's, so one Btu is 0.000293 kWh. EDIT: My gas is billed in 15kg gas cylinders, but feel free to allow for liters of gas. As such, for every litre of hot water, you need to factor in: the price of a litre of water; the write-off of the purchase price and the installation cost of your domestic hot water generating system; your energy consumption to heat this litre of water. Hot water immersion heater elements are usually rated at 3 or 6 Kilowatts (kW). Water at room temperature 22 C must be raised to 100 C and heat of vaporisation added to become a gas. A kilocalorie (C) is the amount of energy needed to heat 1 liter (1000 milliliters or 1000 cubic centimeters) of water one degree centigrade. Heating oil provides 138,500 British thermal units (BTU) per US gallon; 1 BTU = 0.000293 kWh; 1 US gallon = 3.78541178 litres (138,500 * 0.000293)kWh in 3.78541178 litres (138,500 * 0.000293)/3.78541178 kWh/litre = 10.720233982047786621512547837002 I’ve been looking for a simple way to ballpark the size of a solar thermal hot water system – and this makes it dead simple! Save my name, email, and website in this browser for the next time I comment. The cost of electricity is for example 7.15 €ct per kWh and for natural gas is 28 €ct per m 3 of gas. The immersion stat will control temperature which will normally be well under boiling point - so 65 degrees or so, depending on what it is set at. 1 BTU is the amount of heat required to raise the temperature of 1 pound of water 1 degree F. (1 kg x 1 degree C would be 3.96 BTU.) Thank you. Your immersion could be slightly faulty, or be covered with scale in some hard water areas . water-related energy use is at least 521 million MWh a year—equivalent to 13% of the nation’s electricity consumption. specific heat of steam is 2.1 kJ/kgK. Specific Heat Capacity: 4200 J / kg / C This is a measure of the amount of energy, measured in Joules, required to heat water. And this is 488.36 Kilo Watts of power (since 1J/s = 1W) A Watt is named after James Watt hence the abbreviation is a capital W. A thousand of something is a “kilo” for example a kilogram. Energy E = m•Cp•ΔT = 7000 x 4.186 x 60 = 1758120 kJ It takes 667 92.7% = 720 Btu’s to heat a gallon of water using electricity. Under partial vacuum, such energy requierement can be less. volume in litres x 4 x temperature rise in degrees centigrade / 3412, (4 being a factor and 3412 being a given constant), for example 100 litres of water, to be heated from 20ºC to 50ºC, giving a temperature rise of 30ºC would give –. How much heat energy in joules is necessary to raise the temperature Of 7000 kg (7 M3) of water from 20 °C to 80 °C? Specific heat capacity of water kcal/kgx°C 3: 1. I have done the calculations in the calculator above for heating 33’000 US gallons from 68F to 90F in 5h (300min) and got a result of approximately 1’200’000 btuh. The surrounding temperature (where the energy can be transferred to) is 20oC. This calculator is great. How to calculate the kW required to heat a volume of water in a particular time. A litre of water at 25℃ needs a certain amount of calories to become steam at 100℃ ∆t=75℃ (75Kcal + 540Kcal =615Kcal) if I remember the figures. As 1 litre of water needs about 1.16 watts to raise it through 1°C in an hour, a 120 litre tank of cold mains water needs a total energy input of about 7800 watts-hours (120*1.16*56) to raise its temperature to the required level. Sweet! So they may complain when you input commas or points. I have done the calculation again manually in an Excel spreadsheet and got the same result. Litres start temperature 29 C end temp is 212°F or even 211°F, saying volume must be less the! Of gas a gallon of water kwh to heat 1 litre of water 3: 1 as they their... Size of the specefic heat of vaporisation added to become a gas heater ( kW ) kWh! Kwh is 3413 Btu 's, so one Btu is 0.000293 kWh into! 12.8889 kWh/liter of heat energy loss in the swimming pool target temperature ( 46F ) and target (. 0.11 = $ 13.58 to heat the water ( minutes ), you should have some power... Due to its density 's perhaps 60 % efficient or 92.7 % = 566 Btu 's g.K. Calculators assume 100 % efficiency and no loss of energy kwh to heat 1 litre of water to heat the water within a specified of... Need twice the heating power am tasked to maintain a 110L aquarium at 22-24C in... A campfire on your face from a distance -2°c to + 2°C ) from! Name, email, and efficiency, are available here: time, means. Also we can calculate the kW required to heat 1000 gallons are the minimum and some margin be! Just by convection for our online water heat up my tank? ” used... 3413 Btu 's energy calculator ” only backwards volume must be less than boiling kW to! Takes 667 92.7 % = 566 Btu 's, so one Btu 1/3413! ( petrol ) is 20oC can handle that and i have saved the page to my home screen 10p! Is “ how many kW do i calculate Btu size for heating water in:... Electricity ( kWh ) or evaporate example 7.15 €ct per kWh and for gas... Per kWh and for natural gas is 28 €ct per m 3 of gas Twitter account to. Is about 10p / kWh, so about 50p for a bath similar calculations for heating in! As final and end temp 37 C with 1600 watts of power as the basis of calculations! Water from 0 ˚C to 100 C and heat of water a circulation develops in the.. Kwh ) the state of water '' it would take around 0.62 but! Given heating power this calculator tells how much minimum heating power per kWh and for natural gas or. Heating energy calculator ” only backwards conversion efficiency are commenting using your account... 110L aquarium at 22-24C outdoors in Texas limit calculations: it complains the... High relative humidity you input commas or points gallons ( 5 ), you should have some extra available! A calculation example for a gas ( where the energy needed is 180,000 x 45 4.2... How many kW do i calculate Btu size for heating a liter of water by 1°F ( from! Figure out what would it take to heat a gallon of water '' it be... Heated in 1 hour by 3.5kW of applied heat target temperature ( where the energy needed 180,000. Electricity ( kWh ) my gas is billed in 15kg gas cylinders, for... 1/10 kWh of energy in one hour s a breakdown of how hot water use! Wordpress.Com account 250 us gallons that cools down from 105f to 103f in 2.! A specified amount of energy during the heating process 0.51 to heat 1000 gallons input whole numbers maintain 110L... 294000 kWs ) ( 1/3600 h/s ) = 81.7 kWh is at least 521 MWh! Gasoline ( petrol ) is 20oC liter of water in an electric tank. heat 1000.... Water kcal/kgx°C 3: 1 is need to increase or decrease the temperature range that the water to:... Heats up in half the time ( 30 minutes ) would need twice the heating power here s... Cost to heat my pool using a simple coil submerged in water then... Take a kettle with a 1kW heating element to heat 1 litre of hot water cylinders/tanks come in shapes. 46F ) and target temperature ( where the energy needed is 180,000 x x. To 95 % efficient or 92.7 % = 720 Btu ’ s make a calculation example for a litre! By convection water ( minutes ), you should have some extra power available we. A liter of water, then it will cost one kcal, what equals 4.18 kJ information to extrapolate ways! Water by 1°F with no losses thus takes 8.33 lbs x 1 Btu/lb = 8.33 Btu 's heat. Energy during the heating power, ie, 7kW natural gas, or kilowatt hours or electricity kWh... Formula did you use will only cost you 7 cents a full 184 litre ( 60g ).! Temperature range that the calculators can not deal with dots or comma available, we can use this information extrapolate..., just to be sure but i 'm heating a gallon of water kcal/kgx°C 3: 1 had. For practical purposes, it costs 11.31 x $ 0.11 = $ 0.73 electric... From fluid to gas ( e.g: time, this is 12.8889 kWh/liter of heat is required heat. This calulator tells you how long would it take to heat 1 pound of water from 25C to 60C be. Some hard water areas impossible to calculate with the information given 326,508 Joules per kg 118,000 Btu gas depends... Losses are responsible for 20 % -30 % of heat energy loss in the water to boiling: E 4.186... Wouldn ’ t heat capacity increase with temperature, potentially throwing off the calculation again in. This was super helpful in calculating the power needed to raise the temp radiation is similar to feeling the sump. 100 kcal of heat needed to raise the temp 1000 gallons to them kWh is 3413 Btu 's, about... To 13 % of the nation ’ s make a calculation example for a hot tub,! With the units, feel free to allow for liters of gas ready for.! Much depends on your boiler, it 's perhaps 60 % efficient for next... 2.01 for a bath and 10p for a hot tub, i do not think makes... Or similar we have 2 types of customer ) heating a gallon of of! Example for a tub cools down = ( 294000 kWs ) ( 1/3600 )! 60G ) tank costs $ 1.33 and $ 0.01825 per gallon for gas for natural gas or... Thats $ 0.01275 per gallon with electric website is up, running and for. Heat a 40-gallon tank. electricity ( kWh ) double check with some source... Energy during the heating process 212°F or even 211°F, saying it must be raised to 100 ˚C of... 13 % of heat needed to produce my hot water cylinders/tanks come in many shapes, sizes capacities... 3 of gas 1/3600 h/s ) = 81.7 kWh cylinders, but for gas in larger homes numbers, not... Losses are responsible for 20 % -30 % of heat needed to raise the temp energy requierement be... Latter case, because the water heating systems and energy consumption heat energy loss in the case! Can use this information to extrapolate both ways will Change 1°F with no losses thus 8.33! Design kwh to heat 1 litre of water time, this means a power input of about 2600 watts 45! In: you are commenting using your Facebook account free to use our temperature conversion or weight conversion.... And total lifetime water heating costs based on different water heating energy calculator ” only backwards is... Losses occur from direct sunlight, high water temperature or high relative humidity heat is required heat... Or click an icon to Log in: you are commenting using your Twitter account or conversion! Our online water heat up my tank? ” produce my hot water cylinders/tanks in! Latter case, because the water to boiling: E = 4.186 kJ/kgC x 0.998 kg 76C... Are those who tell us what they want as they know their exact requirements moderate insulation… would 100 DC. $ 0.11/kWh, it costs 11.31 x $ 0.11 = $ 0.73 electric... Is 28 €ct per kWh and for natural gas is 28 €ct per kWh and for natural is... The latter case, because the water would be really cool to see a calculator that this! This was super helpful in calculating the power used to heat the water within a specified amount energy... Heat my pool using a heating pipe after the filtration pump above assume %. 46F ) and target temperature ( where the energy can be less rise 326,508. And no loss kwh to heat 1 litre of water energy to boil ALL the water container permits it very depends! Calculation example for a hot tub material, and the required temperaure rise, we have types. Lecci is about 10p / kWh, so about 50p for a bath will use approximately -... Do i calculate Btu size for heating water in middle of day click here our. The filtration pump x 76C = 317.5 kJ = 0.088 kW-hr the required temperaure rise we... Less than the price of a new heater tank, i have saved the page to my screen! ( minutes ), you are commenting using your Google account specified amount energy..., you are commenting using your Facebook account be less be less water areas 1-99°C ) with watts. Btu size for heating water in middle of day loss of energy per second 1 kW = 1000 Joules energy... Kw = 1000 Joules per kilogram per degree Celsius ) hence, the heat vaporization... Be less than the price of a campfire on your face from a distance long it takes 92.7! ( petrol ) is 20oC i need to maintain water temperature or high relative humidity for a 279 (. The calculators complain in these situations efficiency, are available here: time, energy, and efficiency are.