Energy submetering system

• US 4,577,977 A
• Filed: 04/01/1985
• Issued: 03/25/1986
• Est. Priority Date: 04/01/1985
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Pejsa, Jane H.
• Primary Examiner(s): Smith, Robert I.
• Assistant Examiner(s): Will, Thomas B.
• Application Number:
  US06/718,146
• Time in Patent Office: 358 Days
• Field of Search: 374/39, 374/40, 374/41, 65/11 R, 236/94, 62/125, 377/25
• US Class Current: 374/39
• CPC Class Codes: G01K 17/06 Measuring quantity of heat conveyed by flowing media, e.g. in heating systems G01K17/02, G01K17/04 take precedencee.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device

Abstract

A system for submetering artificial energy consumption in a multi-user environment in which a single central system source services the several separate users by means of individual space conditioning subsystems is disclosed which enables accurate proportioning of subsystem energy consumption by monitoring the time intervals of the OFF/ON status of each individual space conditioning subsystem along with the temperature of the conditioned space and utilizes the monitored time intervals and temperature in conjunction with the relative heat capacity of each individual conditioned space to determine the heat consumption of each subsystem relative to all the subsystems served by the central source.

Claims

1. A method for submetering artificial energy consumption in a multi-user environment in which a central source services a plurality of individual users by means of individual space conditioning subsystems comprising the steps of:

monitoring the time interval of the OFF segment and the time interval of the entire OFF/ON cycle for each cycle of each individual space conditioning subsystem;

monitoring the temperature of each conditioned space to determine temperature decay function during the OFF segment and the actual space temperature at the conclusion of each OFF/ON cycle for each cycle of each individual space conditioning means;

determining the total artificial heating or cooling energy supplied by each such individual space conditioning subsystem during each complete OFF/ON cycle according to the relationship

space="preserve" listing-type="equation">Q=MC(T.sub.2 -T.sub.est)

wherein;

Q is the artificial heating or cooling energy;

MC is the relative heat capacity of the conditioned space;

T₂ is the conditioned space temperature at the conclusion of the ON segment of the control cycle; and

T_est is the theoretical extrapolated decay temperature at the end of the complete OFF/ON cycle; and

utilizing the total artificial energy supplied by each individual space conditioning subsystem to determine the heat consumption of each such subsystem relative to all such subsystems served by said central source as a fraction of the total thereof.

2. A method according to claim 1 wherein the theoretical decay temperature T_est is given by ##EQU6## wherein:

T₀ is the conditioned space temperature at the beginning of the OFF segment of the control cycle;

T₁ is the conditioned space temperature at the end of the OFF segment of the control cycle;

t₀ is the time at T₀ ;

t₁ is the time at T, and

t₂ is the time of the complete OFF/ON control cycle.

3. The method of claim 1 wherein said relative heat capacity MC is a factor based on the area of said individual conditioned space.

4. The method of claim 3 wherein said relative heat capacity MC is a factor based on the area of said individual conditioned space.

5. A system for submetering artificial energy consumption in a multi-user environment in which a central source services a plurality of individual users by means of individual space conditioning subsystems comprising:

a plurality of remote monitoring units, one associated with each said space conditioning subsystem further comprising

means for monitoring the time interval of the OFF/ON status of each individual space conditioning subsystem;

means for monitoring the temperature of the conditioned space;

master control means for interrogating each of said plurality of remote monitoring units receiving information therefrom, storing and processing said information and producing an output relative to the energy consumption thereof;

2-way communication means for enabling communication between said master control units and said remote units; and

output means in communication with said master control means for reproducing an output relative to said energy usage.