Recirculating Shower System

Abstract

The invention provides a recirculating shower system comprising a showerhead and shower tray, a circuit configured to collect used water from the shower tray and to recirculate at least part of the used water to the showerhead for further use, the circuit including at least one heat pump to exchange heat between relatively hot water and relatively cold water.

Description

FIELD OF INVENTION[0001]This invention relates to a recirculating shower system. In particular the invention relates to a recirculating shower system in which energy is transferred in the recirculation circuit by one or more heat pumps.BACKGROUND[0002]Water recirculating systems are known for many applications. For example, showers that are arranged to recirculate water within the shower and thereby use less water. Recirculating showers find application principally in portable and mobile applications such as boats and camping vans. For example U.S. Pat. No. 4,828,709 describes a recirculating shower system for use on boats and recreational vehicles. The recirculating water system, which operates with water from a non-mains water supply in the boat or vehicle, comprises filters, a water heater and fresh and used water storage tanks.[0003]In many parts of the world, fresh water is in short supply and measures are taken to preserve the water supply, and there are often incentives offer...

AI Technical Summary

Benefits of technology

The energy recirculating system invention reduces the amount of energy needed to power a heat pump by efficiently transferring existing energy within the system. This results in a system that requires minimal additional heat energy to be input. The system also removes heat from the cold water input, controlling and reducing the temperature of the fresh cold water and maximizing water recirculation percentage.

Problems solved by technology

One problem with the use of recirculating showers in domestic applications lies in regulations that require that any water mixed with mains water must meet water purity standards that the waste water from a shower does not meet.

The maximum power that can be drawn from a standard domestic electricity supply of 240 volts (for example in Australia and across Europe) is 7.5-11.5 kW, which limits the power that is available to heat up the water as it passes through the shower heater.

In some parts of the world, this problem is made worse since the maximum power that can be drawn is lower than 7 kW, e.g. in some areas of China, the maximum power that can be drawn is 3 kW, which ultimately can make electric showers unusable due to the extremely low flow rate of heated water.

They therefore require more complicated plumbing than electric showers.

In addition, if the water supply is not constant, e.g. because someone else is drawing hot water, the temperature of the shower can fluctuate.

However, whilst the system is up to 70% more energy and water efficient than a conventional shower, it has a number of weaknesses, including:The heater requires up to 9 kW of power to provide a shower with a flow rate of 10 litres per minute.

This is expensive and disruptive to install.

In developing nations this can be more power than is supplied to a house via domestic supply, making the shower system not viable in those countries.The water recirculation percentage achieved by the system is dependent on the ambient water temperature of the cold water supplied; the warmer the cold water input, the less water can be recycled.

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