System and method for efficient and expedient delivery of hot water

Abstract

A system and method for detecting and anticipating fluid flow in a pipe utilizing a sensor, a processor, and a time base.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application 60 / 672,159 filed Apr. 15, 2005 and entitled “SYSTEM AND METHOD FOR EFFICIENT AND EXPEDIENT DELIVERY OF HOT WATER.”BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] The present invention relates generally to the mechanical and electrical arts. In particular, the invention relates to systems and methods for detecting fluid flow and for anticipating demands for fluid flow. [0004] 2. Description of Related Art [0005] Modern plumbing systems typically provide both hot water and cold water to various locations in a house or other structure. Water at these locations can be used for many purposes, for example washing, bathing, laundry, drinking and cooking. Each location where water is used has an outlet controlled by valves, also sometimes known as faucets, taps, or spigots. A valve can control the flow or mix hot and cold water to the outlet. Hot and cold...

AI Technical Summary

Benefits of technology

[0024] What is needed is a simple control system that solves these problems by obtaining and analyzing temperature

Problems solved by technology

A problem arises where a hot water outlet is remote from the water heating device because a volume of water at a temperature lower than that provided by the water heating device exists in the interconnecting pipes.

In conventional systems, the purged relatively cold water is allowed to flow down the drain and is therefore wasted.

Thus conventional systems not only waste water, but they require a user to wait until relatively cold water in the pipe or line is purged.

These problems are aggravated in cooler ambient temperatures or in larger homes or buildings with correspondingly larger volumes of water stored in their respective water plumbing systems.

This solution slows the cooling of the water in the hot water lines; however, the water cools eventually and the problems of delay and waste remain.

However, a difficulty arises in trying to determine when to activate the recirculation pump.

Running the pump continuously is highly inefficient because the entire hot water plumbing system is continuously replenished with hot water, continuously remains hot and continuously transfers heat to the surroundings even when hot water is not needed by users.

Continuous pump operation also consumes electricity and may contribute to wear on pipes and lead to repairs or early replacement of plumbing systems and related components.

Pump life is also unnecessarily consumed by operation during periods when there is no user demand for hot water.

The United States Department of Energy has identified control of hot water recirculation systems as a challenge and inadequate control of such systems as a source of energy loss.

Intermittent operation of the recirculation pump can reduce energy and water waste; however, determining when to operate the pump is an unsolved problem.

This type of system keeps the entire hot water circuit at an elevated temperature at all times. This scheme suffers from much the same energy wasting limitation as continuous operation, in that energy is lost from the pipes continuously.

Second, setting such timers is cumbersome and error prone.

Third, these timers offer only a limited number of user selectable on and off events.

Fourth, these timers do not distinguish usage patters that differ with the day of the week or month.

Fifth, these timers do not learn the habits of hot water users.

And finally, these timers have limited resolution and accuracy.

Such events may entirely unpredictable or they may reflect a gradual or sudden change in the user's hot water demand habits.

This uncertainty in predicting when hot water is needed leads users to set the pump to run for much longer periods than the period of actual demand.

This wastes energy for water heating and for pump operation.

In addition, the timer will lose its time setting if electrical power is lost.

In addition, timers do not compensate for changes in daylight savings time or sunrise and day length, all of which can affect a usage schedule and may cause the pump to operate at times when hot water is not needed, or to not operate when needed.

Manually activated demand systems also suffer from various limitations.

Such devices are unfamiliar and children or guests may have difficulty obtaining hot water.

Manually activated water demand switches must be located near each remote hot water outlet, often requiring extensive wiring between each device and the pump.

Where batteries are used, a failed battery causes the system to become inoperative and its benefit is lost.

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