GB2241773A

GB2241773A - Water-saving hot water supply

Info

Publication number: GB2241773A
Application number: GB9004945A
Authority: GB
Inventors: Thomas Robert Edward Bellew
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-03-06
Filing date: 1990-03-06
Publication date: 1991-09-11
Also published as: GB9004945D0

Abstract

A hot water cylinder 1 which is fed with cold water from a header tank 2 supplies hot water to a tap 9 via a normally- closed solenoid valve 6 located adjacent to the cylinder. The valve 6 is controlled from a switch 23 located adjacent to the tap 9, and a vent pipe 20 is connected on the downstream side of the valve. Water is drawn off from the tap 9 when valve 6 is opened by switch 23 and after valve 6 is closed from the switch 23 most of the water will drain from the pipework. A manually operable bypass valve 25 is connected in parallel with the valve 6 for use in the event of a power failure. <IMAGE>

Description

HOT WATER SUPPLIES TECHNICAL FIELD OF THE INVENTION This invention relates to hot water supplies. In particular, the invention is concerned with hot water supplies of the kind which comprise a hot water cylinder, a header tank arranged to feed the cylinder with water, and means for heating water in the cylinder, the cylinder having a cylinder outlet which is connected to a cylinder vent pipe provided with a vent outlet disposed above the header tank, and the cylinder outlet being arranged to feed a hot water issue point.

BACKGROUND In most supplies of the kind specified the cylinder outlet feeds a number of taps or other issue points which are located at various positions around a building in which the supply is installed. Often, at least one of the taps may be located a substantial distance from the cylinder outlet, so that each time water is drawn off from that tap a considerable volume of hot water will remain in the pipework connecting the cylinder outlet to the tap. Unless water is drawn off from the tap again farly quickly this water will soon become cold, so that next time hot water is required to be drawn off from the tap the cooled water must first be discarded. This represents a considerable energy loss in terms of the energy which is put into heating the water in the first place.In addition, this procedure entails a substantial waste of water, which may be particularly significant if the building is supplied via a water meter.

SUMMARY OF THE INVENTION The present invention proposes that in a hot water supply of the kind specified above, an electrically operable valve is connected adjacent to the cylinder outlet to control flow of water to the issue point, the valve being controlled by a switch located adjacent to the issue point, and a secondary vent pipe is connected adjacent to the valve downstream thereof, the secondary vent pipe having a respective outlet which is disposed above the water level of the header tank.

Thus, the flow of water to the issue point is controlled by the valve, and the secondary vent pipe allows water to drain from pipework between the valve and the issue point.

The electrically operable valve preferably comprises a body having water inlet and outlet connections and a vent connection for connection of the secondary vent pipe. The invention includes such a valve for use in the supply.

The secondary vent outlet may conveniently be disposed directly above the header tank.

There is preferably a manually operable bypass valve connected in parallel with the electrically operable valve, so that in the event of a power failure for example, the bypass valve can be opened to allow hot water to be drawn off from the issue point.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is exemplified in the accompanying drawings, in which: Figure 1 is a schemtic diagram of a hot water supply of the invention, and Figure 2 is a side elevation of a solenoid valve for use in the supply.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to Fig. 1, the hot water supply includes a hot water cylinder 1 which is fed from a header tank 2.

The cylinder 1 includes means for heating water in the cylinder such as an immersion heater or a coiled pipe through which a heating medium is circulated. The cylinder also has an outlet 3 which is connected to a vent pipe 4 leading to a vent outlet 5 disposed above the header tank 2. In addition, the cylinder outlet 3 is connected via a normally closed solenoid operated valve 6 and pipework 7 to a tap 9.

The valve 6 is shown in more detail in Fig. 2 and includes a cast metal or moulded plastics body 14 having axially opposed inlet and outlet couplings 15 and 16. A solenoid 17 is secured to the body 14 for opening and closing the valve. In addition, on the outlet side of the valve the body 14 includes a vent outlet 18 which is connected to a secondary vent pipe 20 (Fig. 1) having an outlet 21 located directly above the header tank 2. The supply of electricity to the solenoid 17 is controlled by a switch 23 which is located adjacent to the downstairs tap 9.

A manually operable bypass valve 25 is connected in parallel with the valve 6.

To draw off water from the tap 9, the tap is opened and the switch 23 is closed causing the valve 6 to open.

Hot water is thus permitted to flow to the tap 9. The switch 23 is then opened so that valve 6 closes, but the water remaining in the pipework 7 between the valve 6 and the tap 9 will drain from the tap due to the secondary vent pipe 20 so that very little of the hot water drawn off from the cylinder 1 will be wasted.

Since the valve 6 controls the flow of water to the tap 9, the tap could normally be left open.

In the event of a power failure the bypass valve 25 can be opened to allow hot water to be drawn off.

In order to ensure substantially complete drainage of the pipework between the valve 6 and the tap 9 the pipework should be arranged to ensure that there is a continuous fall on this portion of the pipework.

Additional taps, a shower head, or other draw off points could each be connected to the outlet 3 via a respective solenoid valve which is again conected adjacent to the outlet 3 and individually vented to the header tank. Each additional valve would similarly be operated by a switch located adjacent to the associated issue point, and each valve would again by bypassed by a respective manually operable valve.

Claims

1. Liquid supply apparatus comprising a liquid reservoir having an outlet arranged to feed liquid from the reservoir to an issue point, in which an electrically operable valve is connected adjacent to the reservoir outlet to control flow of water to the issue point, the valve being controlled from a switch located adjacent to the issue point, and a vent pipe it connected adjacent to the valve downstream thereof.

2. Liquid supply apparatus according to Claim 1 in which the electrically operable valve comprif;{^- a body having water inlet and outlet connections arid a vent connection for connection of the vent pipe.

3. Liquid supply apparatus according to Claim 1 or 2, in which there is a manually operable bypass valve connected in parallel with the electrically operable valve.

4. Liquid supply apparatus according to any preceding claim, in which the reservoir comprises a hot water cylinder, and the apparatus includes a header tank arranged to feed the cylinder with water, and means for heating water in the cylinder, the cylinder having cylinder outlet means connected to a cylinder vent pipe provided with a vent outlet disposed above the header tank.

5. Liquid supply apparatus according to Claim 4, in which the vent pipe which is downstream of the valve has an outlet disposed above the water level of the header tank.

6. Liquid supply apparatus according to Claim 5 in which the outlet of the vent pipe which is downstream of the valve has an outlet disposed directly above the header tank.

7. An electrically operable valve for use in apparatus according to any preceding claim, comprising a body having water inlet and outlet connections and a vent connection.

8. Liquid supply apparatus substantially as described with reference to the drawings.