Method and apparatus for determining fuel use efficiency for combustion systems

A method of determining fuel use efficiency from modification to a building having combustion system having a fuel tank said fuel tank having a fuel tank volume, comprising:

• a) collecting a delivery history of a plurality of fuel deliveries to said fuel tank over a preselected period of time prior to said modification, each said delivery substantially filling said fuel tank, said delivery history including:
• i) volume of fuel delivered for each said delivery of said plurality of fuel deliveries and
• ii) number of days elapsing between each said delivery of said plurality of fuel deliveries;
• and
• b) ascertaining heating degree days for each time period between deliveries;
• c) calculating volume of fuel used per day between each delivery;
• d) establishing a relationship between volume of fuel used per day and heating degree days per day for said plurality of fuel deliveries for said combustion system;
• e) modifying said building to improve its fuel use efficiency;
• f) filling said tank after said modification;
• g) making an after modification fuel delivery after said tank was filled after said modification and recording an after modification fuel volume;
• h) calculating the number of elapsed days between filing said tank after modification and said after modification fuel delivery and the elapsed number of heating degree days per day;
• i) calculating an expected fuel use by applying said relationship between volume per day of fuel used and heating degree days per day from said tracked number of elapsed days and the elapsed number of heating degree days per day;
• j) comparing said expected fuel use to said after modification fuel volume.

A system for determining fuel delivery frequency and volume for a combustion system having a fuel tank said fuel tank having a fuel tank volume, comprising:

• a computer said computer including:
• a) a delivery history data base for a number of different combustion systems for a number of fuel deliveries to each combustion system over a preselected period of time, each said delivery substantially filling said fuel tank, said delivery history including
• i) volume of fuel delivered for each said delivery of said plurality of fuel deliveries and
• ii) number of days elapsing between each said delivery of said plurality of fuel deliveries;
• and
• b) a heating degree days data base for each time period between deliveries;
• c) means to calculate a volume of fuel used per day between each delivery;
• d) means to establish a relationship between the volume of fuel used per day and heating degree days per day for said plurality of fuel deliveries for said combustion system;
• e) a data base of a desired volume of fuel for the next delivery to each combustion system;
• f) means to track the number of elapsed days from a last fuel delivery to each said combustion system and the elapsed number of heating degree days per day;
• g) means to periodically calculate an expected fuel use by applying said relationship between volume per day of fuel used and heating degree days per day from said tracked number of elapsed days from the last delivery and the elapsed number of heating degree days per day until said expected use equals said desired volume of fuel;
• h) a signal indicating said combustion system fuel tank requires said desired volume amount.