Multi-Unit HVAC Cost Allocation Using Air Mover Runtime
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for determining energy usage costs in multi-tenanted buildings are inaccurate, unreliable, and costly due to the use of BTU meters, which have poor adoption rates.
Innovation Solution
A method and system that detect and monitor the usage of air movers at pre-selected volumetric flow rates to calculate energy usage costs for individual units based on duration of use, comparing these to the total energy usage of all units, without requiring temperature or flow rate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If BTU meters are used to measure precise inlet and outlet temperatures and flow rate, then measurement precision of energy usage is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the temperature measurement function from the energy monitoring system, eliminating BTU meters that measure inlet and outlet temperatures. Instead, it uses only flow rate data from air movers combined with a simplified calculation method that does not require temperature sensors, thereby reducing device complexity while maintaining energy usage monitoring capability
Solution Approach 2:
The patent uses a standardized energy usage calculation model that copies the relationship between air mover operation and energy consumption across multiple units. By applying the same calculation methodology (energy usage = flow rate × duration × unit cost) to all units, it achieves consistent energy monitoring without requiring complex individualized measurement systems for each unit
2Measurement precision
If BTU meters are deployed to measure energy usage, then individual unit energy cost determination is improved, but reliability decreases due to operational failures
Solution Approach 1:
The patent replaces expensive, complex BTU meters with simpler, more reliable components: air mover flow rate sensors and duration timers. These simpler components have fewer failure points and are more reliable, while still providing sufficient data for accurate energy cost determination through the standardized calculation method
Solution Approach 2:
The system uses data that is already being collected by the air movers themselves (flow rate and operational duration) to determine energy usage. This self-service approach eliminates the need for separate measurement devices that could fail, as the air movers provide the necessary data for energy calculation without requiring additional sensors or measurement infrastructure
3Measurement precision
If BTU meters with temperature and flow rate measurement are used, then energy usage accuracy is improved, but cost increases
Solution Approach 1:
The patent extracts and removes the temperature measurement component from the system, eliminating the need for temperature sensors and associated calibration infrastructure. It relies solely on flow rate measurement and operational duration data, which are already available from air mover controls, thereby significantly reducing system cost while maintaining sufficient energy usage accuracy for billing purposes
Solution Approach 2:
The patent makes the air mover control system multi-functional by using it both for controlling air delivery and for monitoring energy usage parameters. The same flow rate sensors and timers used for air mover operation also provide the data needed for energy cost calculation, eliminating the need for separate measurement infrastructure and reducing overall system cost
Data Source
AI summary
In an aspect, a system is provided for determining an energy usage cost over a time period for a selected unit of a multi-tenanted building. The system includes a fluid mover for the selected unit, configured to operate at at least one pre-selected volumetric flow rate to deliver fluid flow to the selected unit; and a monitoring system configured to:a) detect uses of the fluid movers and detect the associated flow rate;b) determine the duration of use of each fluid mover;c) determine an energy usage cost for the selected unit based on the durations of use, on the flow rate associated with each detected use, on the durations of use for the other fluid movers, and based on a total energy usage cost for all the units of the multi-tenanted building; andd) indicate the energy usage cost for the unit for the time period.