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OIL STORAGE TANKS
ABANDONING OIL TANKS
AGE of OIL TANK
ANODES & DIP TUBES on WATER HEATERS
BURIED OIL TANK ADVICE
BURIED OIL TANKS, FINDING
COMBUSTION PRODUCTS & IAQ
DEFINITION of HEATING & COOLING TERMS
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECTORY of OIL TANK EXPERTS
FILTERS, OIL on HEATING EQUIPMENT
FIRE SAFETY CONTROLS
FLOATING UP OIL STORAGE or SEPTIC TANKS
FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR
FUEL OIL TYPES & CHARACTERISTICS
FUEL UNIT, HEATING OIL PUMPS
GALVANIC SCALE & METAL CORROSION
GAUGES ON HEATING EQUIPMENT
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING OIL TYPES & PROPERTIES
HEATING SYSTEM NOISES
HOME BUYERS GUIDE TO OIL TANKS
NOISE CONTROL for HEATING SYSTEMS
NOISES COMING FROM WATER HEATER
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FUEL TYPES & CHARACTERISTICS
OIL FILL PIPE LEAKS
OIL SPILL CLEANUP / PREVENTION
SOOT on OIL FIRED HEATING EQUIPMENT
STAIN DIAGNOSIS on BUILDING INTERIORS
THERMAL TRACKING & HEAT LOSS
VIDEO GUIDES: Heating System Videos
VIDEO GUIDES - InspectAPedia.com
WINTERIZE A BUILDING
Heating oil usage rate calculations: how to determine the rate of home heating oil consumption: This article describes how long you can heat your building with a known amount of heating oil in the tank, or how to determine how fast your heating oil consumption is likely to empty the heating oil tank. If your oil fired heating boiler, warm air furnace, or water heater has stopped working, one of the first things to check is whether or not you've run out of fuel. If your oil tank is above ground indoors or outside it should have a fuel level gauge installed similar to the one shown in our photo.
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The thermostat and the temperature in my house is always kept at 68 degF.
If my oil tank gauge reading is 1/4 of a tank, how long will that last???
We have no other heating source, ( I'm comfortable).
Reply: It Depends ..
We cannot answer accurately how long your quarter of a tank of heating oil will keep your home heated from just the information you provided, but we can list the facts you'd need to know and how you could estimate or find out the answer:
What Determines How Long a Tank of Oil Will Last?
How long a tank or part of a tank of heating oil will last at a building depends on the following variables:
How to Make a Rough Guess at How Long the Oil Tank Will Last
You can make a very rough guess by noting how many minutes per hour or day your oil burner is running. Oil burners use a spray nozzle that delivers oil at some flow rate in gallons per hour, typically on a home, around .8 to 1.7 gallons per hour.
On your boiler or furnace will be a data tag that gives the maximum recommended flow rate in gallons per hour. With the gallons per hour (GPH) and minutes of run time you are observing you can multiply GPH x (minutes of on time per day / 60 minutes per hour) = number of gallons of oil being consumed a day.
Of course this varies widely as weather and temperatures and house leaks vary, as we outlined just above.
So if you know your oil tank size (say 500 gallons) you can make a very rough guess at how much oil is in the oil tank - say 125 gallons. I'd round down to 100 to be on the safe side since the tank is probably round or oval.
Example of Calculation of Days Supply of Heating Oil Remaining in an Oil Storage Tank
Here is an example using some sample numbers: 100 gallons of oil in the oil tank and a 1 GPM oil burner nozzle.
Watch out: calculating the number of days of heat that oil in your tank can provide is very rough, since outdoor temperatures, wind, and other conditions keep changing. Your oil company knows this and uses a more sophisticated approach using degree days - a factor that considers not only your oil burner's usage rate but how that rate will vary as a function of changes in outdoor temperature.
Bottom line: if your oil tank shows 1/4 full or less and it's during the heating season, you ought to call your oil company and ask for a delivery soon.
In an emergency if you are out or almost out of heating oil and your oil company can't make a delivery soon enough, the oil company can send a technician who can bring a 5-gallon container of oil to pour into your heating oil tank, or you can yourself purchase diesel fuel (in an emergency only) at a gas station and use that.
If you run out of heating oil, re-starting the oil burner may require a service call from your heating company as it may be necessary to bleed air out of the oil piping in order to properly re-start the oil burner.
Extreme danger: Double watch out: if you are purchasing fuel to use in your heating oil tank, be sure it's heating oil or in an emergency, diesel fuel or kerosene. If you put other flammables into your heating oil tank you are likely to blow up the building and kill everyone.
Your Oil Company Knows How Long Your Oil Tank Will Last
If you are on automatic oil delivery the question of how long the oil tank will last is easier to answer - your oil company will have computerized data showing your home's oil consumption rate as a function of "degree days" - a rough measure of how many hours at what outdoor temperature your home is being exposed to winter weather. They can tell you your home's energy consumption rate more accurately.
The depth of the oil in the tank is measured by marking the top of the tank on the stick or oil tank gauge, then placing the stick into the oil tank and withdrawing it. The oil level seen on the stick is compared with the distance from bottom of the stick (bottom of the oil tank) to top of the oil tank (which we marked on the stick).
In the old days people kept an oil tank stick that was already marked and calibrated to tell them how much oil was in their tank.
Today if we use a folding measuring rule or a generic "stick" to "stick the oil tank" to check oil level, we need to know the volume and shape of the tank as well as the depth of oil on the stick in order to calculate the number of gallons in the oil tank accurately.
In the photo our client is discovering a surprise buried oil tank at a farm we were inspecting.
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Frequently Asked Questions (FAQs) about the rate of consumption of home heating oil
Question: how many liters of kerosene is my house using per hour?
I would like to know how much liters is my house heating using per hour. I bought 181 liters of Kerosene for my heating, how long will it last? Our thermostat has a scale that goes from 7 to 1 and right now is at 1. I've been using 4 hours of heating per day. My heating has a power of 17.6 kW and efficiency of 65%. Any clues on how much liters it is consuming per hour and how long my 181 liters will last? Thank you - L.F.S. 3/15/2013
Your oil burner sprays oil through a nozzle whose job is to aerosolize the oil so that it can be ignited and burned in the combustion chamber. Every oil burner nozzle has a number stampled into its body that gives a flow rate in gallons per hour or GPH (convertible to liters per hour or LPH if you like). For example a nozzle marked 1.25 is rated to burn 1.25 gallons of No. 2 home heating oil per hour, presuming that the oil burner's pump is also pushing oil through the nozzle at a specified pressure (typically 100 psi). If your oil burner is set to a higher pressure (say 140 psi) then more oil per hour is going to pass through that nozzle.
So you could ask your heating service tech to tell you what sized oil burner nozzle is on your heater and what pressure the system runs-at.
But this data is only conceptual - it will NOT tell you how many days of heat you have in your 181 liters of kerosene.
Translating your question in to how long your tank of kerosene is going to last is a bit more tricky than just knowing the kerosene or heating ol burn rate.
The number of hours per day that your oil burner will be "on" depends on
How could we know the heat loss rate of your home from just your email? If someone leaves a window open or turns the temperature up or the outside temperature drops, all of the data changes.
3/23/2014 cass said:
"Here is an example using some sample numbers:
Here you jump from 15m/hour to 30min/hour...
30 (minutes of "burner on time" per hour) x 24 (hours in a day) = 720 minutes of burner on time per day
GPD = 1 (GPH) x (720 (burner on time per day) / 60 (minutes per hour)) = 12 gallons of oil used per day.
Now you put 6 gal / day, but calculate on 12 gal per day...
100 G (gallons of oil in the tank) / 6 (gallons of oil used per day) = 8 days of heating oil supply remaining"
I was confused by this for a bit, until I realized this.
Thanks again for putting this out there!
Thanks Cass, I have corrected the math. We appreciate your careful reading and your taking the time to comment - working together makes us smarter.
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