System And Method For Estimating Periodic Fuel Consumption for Cooling Of a Building With the Aid Of a Digital Computer

• US 20190311283A1
• Filed: 06/24/2019
• Published: 10/10/2019
• Est. Priority Date: 02/25/2015
• Status: Active Grant

• Current Assignee: Clean Power Research LLC
• Original Assignee: Clean Power Research LLC
• Inventors: Hoff, Thomas E.
• Granted Patent: US 11,921,478 B2
• Time in Patent Office: Days
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 2120/00 Control inputs relating to users or occupants
• CPC Class Codes: G05B 17/00 Systems involving the use of models or simulators of said systems G05B13/00, G05B15/00, G05B19/00 take precedence
• CPC Class Codes: G05D 23/00 Control of temperature
• CPC Class Codes: G06F 17/12 Simultaneous equations , e.g. systems of linear equations
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 2119/08 Thermal analysis or thermal optimisation
• CPC Class Codes: G06F 30/13 Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
• CPC Class Codes: G06N 7/08 using chaos models or non-linear system models
• CPC Class Codes: G06Q 10/04 Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" market predictions or forecasting for commercial activities G06Q30/0202
• CPC Class Codes: G06Q 50/06 Energy or water supply

Abstract

A system and method to determine building thermal performance parameters through empirical testing is described. The parameters can be formulaically applied to determine fuel consumption and indoor temperatures. To generalize the approach, the term used to represent furnace rating is replaced with HVAC system rating. As total heat change is based on the building'"'"'s thermal mass, heat change is relabeled as thermal mass gain (or loss). This change creates a heat balance equation that is composed of heat gain (loss) from six sources, three of which contribute to heat gain only. No modifications are required for apply the empirical tests to summer since an attic'"'"'s thermal conductivity cancels out and the attic'"'"'s effective window area is directly combined with the existing effective window area. Since these tests are empirically based, the tests already account for the additional heat gain associated with the elevated attic temperature and other surface temperatures.

Claims

1. A system for estimating periodic fuel consumption for cooling of a building with the aid of a digital computer, comprising:

a non-transitory computer readable storage medium comprising program code;

a computer interfaced to the storage medium and configured to execute the program code to performs steps to;

find thermal conductivity, thermal mass, effective window area, and HVAC system efficiency of a building based on empirical testing of the building over a monitored time frame;

record a difference between indoor and outdoor temperatures of the building during the monitored time frame;

define a time span over which to estimate;

retrieve an average occupancy, average internal electricity consumption, average solar resource, HVAC system rating, and HVAC system status as applicable to the building over the monitored time frame; and

estimate the periodic fuel consumption for cooling over the modeled time span based on the building'"'"'s thermal conductivity, temperature difference, number of time periods comprised in the modeled time span, average occupancy, average internal electricity consumption, effective window area, and average solar resource.

2. A system according to claim 1, the computer further configured to:

finding the periodic fuel consumption for cooling HeatOrCoolR^HVACη

^HVACStatus(H) in accordance with;

3. A system according to claim 1, further comprising the steps of:

the HVAC system configured to operate in the absence of solar gain into the building during an empirical test over a short duration during which the HVAC system is;

performing an empirical test over a short duration during which the HVAC system is

the computer further configured to;

observe a change in the indoor temperature between the indoor temperature at the start of the empirical test and the indoor temperature at the end of the empirical test;

determine the indoor temperature as the average indoor temperature of the building over the short duration;

determine the outdoor temperature as the average outdoor temperature of the building over the short duration;

determine the internal electricity consumption as the average internal electricity consumption over the short duration;

base the average occupancy as observed in the building during the short duration;

determine the solar resource as the average solar resource produced over the short duration; and

determine the HVAC system status as observed in the building during the short duration; and

find the HVAC system efficiency as a function of the thermal mass and the change in the indoor temperature, the thermal conductivity and the temperature difference, the average occupancy, and the average internal electricity consumption, all over the rating and status of the HVAC system.

4. A system according to claim 3, the computer further configured to:

find the efficiency of the HVAC system η

^HVAC of the building in accordance with;

5. A system according to claim 3, the computer further configured to:

find effective window area W of the building in accordance with;

6. A system according to claim 3, the computer further configured to:

find the thermal mass M of the building in accordance with;

7. A system according to claim 3, the computer further configured to:

find the thermal conductivity UA^Total of the building in accordance with;

8. A system according to claim 1, the computer further configured to remotely control the HVAC system during the empirical test.

9. A system according to claim 1, the computer further configured to remotely interface to a thermometer located outside the building to obtain the outdoor temperatures.

10. A system according to claim 1, the computer further configured to remotely interface a thermometer inside the building to obtain the indoor temperatures.

11. A method for estimating periodic fuel consumption for cooling of a building with the aid of a digital computer, comprising the steps of:

finding thermal conductivity, thermal mass, effective window area, and HVAC system efficiency of a building with involvement of a computer through empirical testing of the building over a monitored time frame;

recording with involvement of the computer a difference between indoor and outdoor temperatures of the building during the monitored time frame;

defining with the computer a time span over which to estimate;

retrieving with the computer an average occupancy, average internal electricity consumption, average solar resource, HVAC system rating, and HVAC system status as applicable to the building over the monitored time frame; and

estimating the periodic fuel consumption for cooling over the modeled time span based on the building'"'"'s thermal conductivity, temperature difference, number of time periods comprised in the modeled time span, average occupancy, average internal electricity consumption, effective window area, and average solar resource.

12. A method according to claim 11, further comprising the step of:

finding the periodic fuel consumption for cooling HeatOrCoolR^HVACη

^HVACStatus(H) in accordance with;

13. A method according to claim 11, further comprising the steps of:

performing an empirical test over a short duration during which the HVAC system is operated in the absence of solar gain into the building, comprising the steps of;

observing a change in the indoor temperature between the indoor temperature at the start of the empirical test and the indoor temperature at the end of the empirical test;

determining the indoor temperature as the average indoor temperature of the building over the short duration;

determining the outdoor temperature as the average outdoor temperature of the building over the short duration;

determining the internal electricity consumption as the average internal electricity consumption over the short duration;

basing the average occupancy as observed in the building during the short duration;

determining the solar resource as the average solar resource produced over the short duration; and

determining the HVAC system status as observed in the building during the short duration; and

finding the HVAC system efficiency as a function of the thermal mass and the change in the indoor temperature, the thermal conductivity and the temperature difference, the average occupancy, and the average internal electricity consumption, all over the rating and status of the HVAC system.

14. A method according to claim 13, further comprising the step of:

finding the efficiency of the HVAC system η

^HVAC of the building in accordance with;

15. A method according to claim 13, further comprising the step of:

finding effective window area W of the building in accordance with;

16. A method according to claim 13, further comprising the steps of:

finding the thermal mass M of the building in accordance with;

17. A method according to claim 13, further comprising the steps of:

finding the thermal conductivity UA^Total of the building in accordance with;

18. A method according to claim 11, further comprising one or more of the steps of:

remotely controlling the HVAC system during the empirical test with by the computer.

19. A method according to claim 11, further comprising the step of:

remotely interfacing by the computer to a thermometer located outside the building to obtain the outdoor temperatures.

20. A method according to claim 11, further comprising the step of:

remotely interfacing by the computer to a thermometer inside the building to obtain the indoor temperatures.