HVAC Power Estimation Using Capacity Tables and Correction Factors
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Solution Overview
Problem
Current methods for estimating power consumption of HVAC systems are inaccurate due to sensor errors and do not account for non-standard operating conditions, such as clogged filters or incorrect refrigerant gas charge, leading to significant errors in energy management and billing.
Innovation Solution
A meterless estimation method using HVAC data collector and processor to obtain power consumption data from capacity tables and apply correction factors based on compressor data and thermal cycle parameters, reducing errors and costs associated with traditional power metering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If power meters are used to measure power consumption, then measurement accuracy is improved, but installation cost increases
Solution Approach 1:
The patent creates a virtual model (capacity table) that replicates the relationship between operating conditions and power consumption based on manufacturer test data. This virtual copy allows estimation without physical power meters, achieving measurement accuracy while eliminating installation costs.
Solution Approach 2:
The patent replaces the mechanical/electrical power metering system with a computational estimation system using capacity tables and operating parameter data. This substitution eliminates the need for physical measurement devices while providing power consumption information.
2Ease of manufacture
If thermal cycle running parameters are used to estimate power consumption, then installation cost is reduced, but measurement precision deteriorates due to sensor reading errors
Solution Approach 1:
The patent performs preliminary work by having the manufacturer create comprehensive capacity tables during product testing under various controlled conditions. These pre-computed tables contain power consumption data for different operating scenarios, allowing accurate estimation during actual operation without requiring complex real-time measurements.
Solution Approach 2:
The patent introduces capacity tables as an intermediary between operating parameters and power consumption estimation. Instead of directly measuring power or using simple thermal parameters, the system uses capacity tables to translate operating conditions into accurate power consumption estimates, reducing the impact of sensor errors.
3Measurement precision
If reverse carnot or cooling cycle is used to estimate power consumption, then theoretical accuracy is improved, but device complexity increases due to multiple data points requirements
Solution Approach 1:
The patent shifts the complexity from runtime operation to product development phase. Manufacturer performs comprehensive testing and creates capacity tables in advance, containing all necessary power consumption data for various operating conditions. During actual operation, the system simply looks up values in these pre-computed tables, avoiding complex real-time calculations and multiple sensor requirements.
4Ease of operation
If capacity tables from product data book are used, then ease of operation is improved, but measurement precision deteriorates under nonstandard operating conditions
Solution Approach 1:
The patent makes the capacity table system dynamic by allowing interpolation between tabulated values and adjustment for actual operating conditions. Instead of relying on fixed standard condition tables, the system adapts to varying conditions (different refrigerant charges, piping configurations, ambient temperatures) by computing appropriate estimates based on the closest matching capacity table data.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method provides more accurate power consumption estimates with reduced errors (about 10% less than prior art) and eliminates the need for costly power meter devices, saving time and effort in data acquisition.
Implementation Method 1
As the liquid refrigerant inside the evaporator coil converts to gas, heat from the indoor air can be absorbed into the refrigerant, thus cooling the indoor air
Implementation Method 2
heat from the indoor air can be absorbed into the refrigerant
Implementation Method 3
The compressor can pressurize the refrigerant gas and send the refrigerant gas into the condenser coil
Implementation Method 4
An outdoor fan can pull outdoor air through the condenser coil, allowing the outdoor air to absorb heat from the refrigerant gas and release it outside
Implementation Method 5
the refrigerant can be converted back to a liquid
Data Source
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AI summary
A method for estimating power consumption of a heating, ventilation and air conditioning (HVAC) system in a building comprising: a step of collecting HVAC data of the HVAC system by a HVAC data collector; a step of obtaining, by a processor, a first power consumption data of the HVAC system based on a plurality of capacity tables of the HVAC system and the collected HVAC data; a step of obtaining, by the processor, a second power consumption data of the HVAC system based on the first power consumption data, the HVAC data, and a correction factor model, for estimating the power consumption of the HVAC system.