Method and device for indicating the fuel consumption and/or efficiency of a heating unit

1. A method for indicating consumption in billable combustible and free energy gathered in an outside environment of a heating unit to a user wherein said heating unit includes at least one heat pump with a thermal compressor driven by a thermal energy feed, a heating fluid distribution circuit and a plurality of convectors or radiators receiving an energy quantity Q 1 , the thermal compressor mainly using as a cold source the heating fluid distribution circuit and the thermal energy feed being at least provided by burning a billed combustible, wherein the method comprises at least:

A—measuring, via a combustible meter, over a preset time period, a quantity of billable combustible burnt to provide at least a part of the thermal energy feed to the thermal compressor of the heat pump and determining, using the quantity of billable combustible burnt over the preset time period, a corresponding amount of a billed energy quantity Q 2 F,

B—measuring, via first and second temperature sensors and a flow-rate sensor, over the preset time period, on a heat transfer circuit of the heat pump, a temperature of a heat transfer fluid before and after passing through an outside exchanger and a flow-rate of the heat transfer fluid passing through the outside exchanger and determining, over the preset time period, based on said measurements, an energy quantity Q 3 corresponding to a quantity of said free energy gathered in the outside environment, where the energy quantity Q 3 is obtained by integrating a temperature difference across the outside exchanger multiplied by the flow-rate across the outside exchanger,

C—displaying at least the consumption of the heating unit in billable combustible and free energy gathered in the outside environment by displaying the energy quantities Q 2 F and Q 3 , corresponding to the preset time period, on a display screen and/or a document intended for billing the client.

2. The method according to claim 1 , wherein the thermal energy feed is mainly provided by a combustible burner.

3. The method according to claim 2 , wherein the combustible includes gas and/or domestic fuel oil and/or wood pellets, and the billed energy quantity Q 2 F is measured by a meter.

4. The method according to claim 1 , wherein a financial equivalent for nonbillable energy quantities is additionally calculated, wherein the non-billable energy quantities are calculated as being equal to Q 1 -Q 2 F, and wherein this financial equivalent is to be displayed.

5. The method according to claim 1 , wherein the heat pump does not have an electric pump and an electric consumption of the heating unit is less than 10% of Q 1 nom, where Q 1 nom corresponds to a nominal power of the heating unit.

6. A device for indicating a consumption in billable combustible and free energy gathered in an outside environment of a heating unit, said heating unit including at least one heat pump having a thermal compressor moved by a thermal energy feed, a heating fluid distribution circuit and a plurality of convectors or radiators, the thermal compressor mainly using as a cold source the heating fluid distribution circuit and the thermal energy feed being at least provided by burning a billed combustible, wherein the device comprises:

first and second temperature sensors configured to respectively measure, on a heat transfer circuit of the heat pump, temperatures of a heat transfer fluid before and after passing through an outside exchanger of the heat pump,

a flow-rate sensor configured to measure a flow-rate of the heat transfer fluid passing through the outside exchanger,

an electronic unit configured to determine an energy quantity Q 3 corresponding to a quantity of said free energy collected in the outside environment based on the measurements, on the heat transfer circuit, of the first and second temperature sensors and the flow-rate sensor,

a combustible meter configured to determine an energy quantity Q 2 F corresponding to a billed consumption of combustible consumed by the heat pump thermal compressor based on measurements provided by said combustible meter,

wherein the first and second temperature sensors, the flow-rate sensor, and the combustible meter are connected to the electronic unit,

wherein the electronic unit is adapted for calculating the energy quantities Q 2 F and Q 3 corresponding to a consumption of the heating unit in billable combustible and free energy gathered in the outside environment over a preset time period, and/or for displaying values of the energy quantities Q 2 F and Q 3 on a display screen, and/or for preparing the values of the energy quantities Q 2 F and Q 3 for printing of a document intended for billing the client.

7. The device according to claim 6 , wherein the combustible is gas or domestic fuel oil and wherein the combustible meter includes a gas or fuel oil meter configured to measure the energy quantity Q 2 F and disposed on a channel supplying the heating unit with said combustible.

8. The device according to claim 6 , wherein the heat pump does not have an electric pump and an electric consumption of the heating unit is less than 10% of Q 1 nom, where Q 1 nom corresponds to a nominal power of the heating unit.

9. A method for indicating consumption in billable combustible and free energy gathered in an outside environment of a heating unit to a user wherein said heating unit includes at least one heat pump with a thermal compressor driven by a thermal energy feed, a heating fluid distribution circuit, and a plurality of convectors or radiators receiving a first energy quantity Q 1 , the thermal compressor mainly using as a cold source the heating fluid distribution circuit and the thermal energy feed being at least provided by burning a billed combustible, wherein the method comprises at least:

measuring, over a preset time period, using a meter or a combustible flow rate meter, a quantity of combustible burnt by a combustible burner and/or a quantity of thermal energy provided by a combustionless energy source, said combustible burnt by a combustible burner and said combustionless energy source providing the thermal energy feed of the thermal compressor, and determining, over said preset time period, a second energy quantity Q 2 corresponding to said thermal feed provided to the thermal compressor of the heat pump,

measuring, over the preset time period, the first energy quantity Q 1 supplied to the distribution circuit using first and second indoor temperature sensors configured to respectively measure, on the heating fluid distribution circuit, temperatures of a heating fluid before and after passing through the plurality of convectors or radiators and an indoor flow-rate sensor configured to measure a flow rate of the heating fluid distribution circuit, where the first energy quantity Q 1 is obtained by integrating a temperature difference across the convectors or radiators, multiplied by the flow-rate across the convectors or radiators,

determining, over the preset time period, a third energy quantity Q 3 corresponding to a quantity of said free energy gathered in the outside environment, wherein the third energy quantity Q 3 is obtained by subtracting Q 2 from Q 1 , namely Q 3 =Q 1 −Q 2 ,

measuring, via a combustible meter, over a preset time period, a quantity of billable combustible burnt to provide at least a part of the thermal energy feed to the thermal compressor of the heat pump and determining, using the quantity of billable combustible burnt, over said preset time period, a corresponding amount of a billed energy Q 2 F,

displaying at least the consumption of the heating unit in billable combustible and free energy gathered in the outside environment by displaying the energy quantities Q 2 F and Q 3 , corresponding to the preset time period, on a display screen and/or a document intended for billing the client.

10. The method according to claim 9 , further comprising calculating an efficiency of the heating unit by calculating Q 1 /Q 2 F.