UV Sanitation Loop for Legionella Control in Hot Water Heating
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Solution Overview
Problem
Existing water heating and treatment systems face challenges in effectively suppressing pathogens and bacterial content, particularly Legionella, due to energy-intensive bulk heating methods and the risk of contamination when sanitation devices fail, leading to potential Legionnaires' disease outbreaks.
Innovation Solution
A water heating and treatment system incorporating a UV lamp and anti-scale device, with a sanitation loop that circulates hot water above 66°C for at least two minutes, and a controller that activates the sanitation loop on a schedule or in response to device failures, ensuring pathogen suppression without significant energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bulk heating methods are used to suppress pathogens, then pathogen suppression effectiveness is improved, but energy consumption increases
Solution Approach 1:
The system divides the water heating and sanitation process into distinct segments: a sanitation loop that circulates water through the heater for pathogen suppression, and a separate hot water supply system for user needs. This allows targeted heating only when and where needed for sanitation, rather than bulk heating of all water, thereby maintaining pathogen suppression effectiveness while reducing overall energy consumption.
Solution Approach 2:
The sanitation loop operates periodically rather than continuously, circulating water through the heater at scheduled intervals or in response to detected contamination events. This periodic operation achieves necessary pathogen suppression while avoiding the continuous energy consumption associated with maintaining all water at sanitization temperatures.
2Reliability
If sanitation devices are installed to suppress pathogens, then pathogen suppression effectiveness is improved, but system complexity increases
Solution Approach 1:
The patent combines multiple functions into integrated components: the sanitation loop is integrated with the existing water heater and control systems, and the recirculation pump is coordinated with the heater's existing circulation mechanisms. This merging approach achieves effective pathogen suppression while minimizing the addition of separate, complex subsystems.
Solution Approach 2:
The water heater serves multiple functions: it provides normal hot water heating for user comfort and simultaneously acts as a sanitation device when the sanitation loop is activated. The control system also performs dual roles by managing both routine water heating operations and sanitation cycle coordination. This multi-functionality reduces the need for dedicated, complex sanitation equipment.
3Reliability
If the sanitation loop operates continuously to ensure pathogen suppression, then reliability of pathogen mitigation is improved, but energy consumption increases
Solution Approach 1:
The sanitation loop is designed to operate periodically rather than continuously, circulating water through the heater at scheduled intervals or in response to detected contamination events. This periodic operation achieves necessary pathogen suppression while avoiding the continuous energy consumption that would result from constant operation, thereby resolving the contradiction between reliability and energy use.
Solution Approach 2:
The control system monitors system operation and can activate the sanitation loop in response to detected contamination events or scheduled intervals. This feedback-based activation ensures pathogen suppression reliability by responding to actual or potential contamination risks while avoiding unnecessary continuous operation, thereby reducing energy consumption.
4Reliability
If the water heater increases temperature to sanitization levels, then pathogen suppression effectiveness is improved, but risk of scalding increases
Solution Approach 1:
The system separates the sanitation function from the user supply function by implementing a dedicated sanitation loop that circulates water through the heater internally, distinct from the hot water supply lines to users. This segmentation allows the heater to reach high sanitization temperatures in the sanitation loop without exposing users to scalding risks through the separate supply system.
Solution Approach 2:
The sanitation loop acts as an intermediary system that enables high-temperature pathogen suppression while protecting users from scalding. The loop circulates water through the heater's heat exchanger or internal passages for sanitation, then returns it to the cold water supply or maintains it separate from user supply lines, thereby mediating between the need for high temperatures and the need to protect users.
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
The system effectively reduces pathogens and bacterial content in domestic water systems with reduced energy costs and ensures continuous sanitation even when sanitation devices fail, providing a reliable pathogen mitigation strategy.
Implementation Method 1
A water heating and treatment system with UV lamp and anti-scale water treatment sanitation for suppression of pathogens and undesired bacterial content
Implementation Method 2
A water heating and treatment system with UV lamp and anti-scale water treatment sanitation for suppression of pathogens and undesired bacterial content
Implementation Method 3
A water heater sanitation loop includes a sanitation loop pump to circulate hot water within the water heater
Implementation Method 4
a water temperature of the water heater to increase momentarily to a sanitization temperature above 66°C (151°F) for one or more periods of at least two minutes
Data Source
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AI summary
A water heating and treatment system with UV lamp and anti-scale water treatment sanitation for suppression of pathogens and undesired bacterial content in a domestic hot water system includes an anti-scale device, and a UV sanitation lamp. A single or multiple mixing station supplies heated water to one or multiple temperature zones. A water heater sanitation loop includes a sanitation loop pump to circulate hot water within the water heater. In some embodiments, a three-way return water diverter valve allows for safe sanitation of a domestic hot water system by diverting over temperature re-circulated water away from the mixing valve to a drain, as needed. A method for treating hot water to suppress pathogens and undesired bacterial content in a domestic hot water system is also described.