Structured hot water demand flow control system with expansion tank

Abstract

In a hot water system for providing intermittent hot water, a separate holding vessel is provided and disposed in a hot water line between a hot water source and a plumbing fixture for blending of incoming hot water with residual water in the vessel in order to decrease cold water surges at the plumbing fixture upon repeated use of hot water in the plumbing fixture. A bladder disposed within the separate holding vessel accommodates for thermal expansion of the water and positioning of vessel inlets and outlets prevents stagnation of water in the vessel.

Description

[0001]This application is a continuation-in-part of U.S. Ser. No. 12 / 048,545 filed Mar. 14, 2008 which is continuation-In-part of U.S. Ser. No. 11 / 602,071 filed Nov. 20, 2006. These applications are to be incorporated herein in their entirety by this specific reference thereto.[0002]The present invention is generally directed to plumbing systems and is more particularly directed to plumbing systems of high thermal efficiency.[0003]Certain types of water heaters, for example, gas tankless water heaters, after being shut down and restarted allow cold water to flow through the water heater for a number of seconds before the burners are able to bring the temperature up to the water heater set point. This creates a cold water “plug” or “sandwich” effect in hot water line. That is, the hot water line, while still full of mostly hot water, experiences several seconds during which cold water flows through the water heater before the burners start to fire up and heat the water, thus creating...

AI Technical Summary

Benefits of technology

"The present invention provides an improvement in a hot water system that reduces cold water surges (also known as \"plugs\" or \"sandwiches\") at the plumbing fixture. This is achieved by a separate holding vessel that blends incoming hot water with residual water to decrease the amount of cold water. The vessel has a volume of water for a given length greater than the volume of water in the hot water line for the given length. The system also includes a recirculating line or a cold water line for circulating cold water back to the hot water source. The holding vessel may incorporate a bladder for sealing a gas within a portion of the vessel which accommodates thermal expansion of water in its system."

Problems solved by technology

In this case, thermal expansion can cause pressure buildup in water systems.

This spillage results in wasted energy and a potential safety hazard.

The use of a convention expansion tank, such as, for example set forth in U.S. Pat. No. 4,784,181 introduces yet another problem in potable water systems in that stagnant water accumulates in the expansion tank which thereafter may contaminate the entire water system.

Images