GB2454180A

GB2454180A - A cover and solar heater for a swimming pool

Info

Publication number: GB2454180A
Application number: GB0721190A
Authority: GB
Inventors: John Humphrey Hussey
Original assignee: J H HUSSEY
Current assignee: J H HUSSEY
Priority date: 2007-10-29
Filing date: 2007-10-29
Publication date: 2009-05-06
Also published as: GB0721190D0

Abstract

A swimming pool heater includes a flexible buoyant cover 1 formed by upper 8 and lower 9 layers with a channel 5 therebetween. Pool water is pumped through the channel to be heated by the sun 7. Preferably one or both of the layers contain bubbles 10 for buoyancy. The upper layer of the cover may be translucent and the lower layer may be heat absorbing. The channel can have an inlet 12 and outlet 14; they can be at opposite ends of the cover, possibly with the inlet higher than the outlet. The outlet is preferably connected to a perforated discharge pipe 6; the pipe may form a resilient edging for the cover. There can be several channels separated by waterproof seams. The cover is preferably mounted in a storage reel 3 which may distribute the pool Water to the cover. A method and kit for installation are also claimed.

Description

1 2454180

SWIMMING POOL HEATER

The present invention relates to apparatus for heating an enclosed body of water. It is particularly concerned with apparatus for heating a swimming pool.

Domestic and commercial swimming pools are typically heated by circulation of the pool water through a heating device.

Commonly used devices for heating swimming pools include electrical resistance heaters. These are compact and inexpensive to buy, but are inefficient, expensive to run and may also be complex to install due to the high power of electricity required. Gas or oil burning heaters are also available, which are cheaper to run than a resistance heater, and are quick methods of heating, but produce high levels of emissions and consume fossil fuels.

More environmentally friendly options include heaters powered by solar panels and heat pumps. Heat pumps work by taking free heat from the ambient air and transferring it to the pool water. They are efficient and reliable but can be expensive to buy and install, which is a particular disadvantage for owners of private domestic pools.

At its most general, the present invention proposes a swimming pool heater in the form of a two-layer floatable blanket, in which the pool water is circulated in a space between the layers and directly heated by incident sunlight.

Accordingly, a first aspect of the present invention provides a swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is translucent and at least one of the layers is composed of a bubble material.

At least one of the layers of the heating blanket is a bubbled layer, but for added buoyancy it is preferred that the upper and lower layers are each composed of a bubble material, which may be the same or different.

The top layer of the heating blanket is translucent and so allows sunlight to pass through it into the channel below.

This means that, when the blanket is in use, pooi water contained in the channel is heated by the solar energy. The translucent material is preferably a translucent plastic such as polyethylene.

Most preferably the top layer is a translucent bubble material, for example a translucent polyethylene sheet containing a plurality of air-containing pockets. The use of a translucent bubbled layer has the added advantage that the bubbles can act like lenses, and may magnify the solar radiation, to increase the efficiency of the heating.

A second aspect of the invention provides a swimming pool heater including a flexible, buoyant blanket having an upper layer of a bubble material and a lower layer of a bubble material and a channel between the layers to receive pool water to be heated.

Preferably the upper layer is a translucent bubble material as described above in relation to the first aspect.

A third aspect of the invention provides a swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers to receive pool water to be heated, wherein the upper layer is composed of a bubble material.

Preferably the upper layer is translucent, as described above in relation to the first and second aspects.

The flexible, buoyant blankets, in the swimming pooJ heaters of the first, second and third aspects of the invention function in similar ways. Preferred features, which may be present alone or in any appropriate combination, of the blankets are described below, and these may apply equally to heaters according to any of these aspects.

The blanket may serve as a cover for the pool as well as providing the heating function. The insulating effect of the blanket may reduce heat loss and evaporation from the pool.

The blanket is buoyant, due to the use of a bubble material as one or both of the upper and lower layers, and floats on the surface of the pooi.

Preferably the blanket is of a size and shape to fit the pool to be covered. Typically, the blanket will be substantially rectangular in shape to fit a standard pool, but curved and other shaped pools are also known in the art and the blanket could be shaped accordingly. The blanket may be any appropriate size. As is well known in the art, sizes of swimming pool vary from small pools, e.g. in domestic gardens, to Olympic sized pools.

Floating swimming pool covers are widely used to prevent heat loss from pools, and may comprise bubble materials.

Bubble swimming pool covers usually consist of a single layer of bubble material, typically a polyethylene sheet, filled with air pockets. Other bubble materials are also known, for example bubble wrap' used in packaging.

As used herein, the term bubble material' refers to a sheet material, preferably a polymeric material, containing a plurality of bubbles or air pockets. The air pockets are preferably distributed throughout the material and are filled with air, which is at sufficient pressure to support the open, bubbled structure of the material.

Such bubble materials may be formed by a process in which a polymer resin, such as polyethylene resin, is heated and then extruded into stacked sheets of polymer film. A layer of the film is wrapped around a drum with holes punched in it, and suction is applied drawing the web of film into the holes, which forms the bubbles. A second layer of film is then laminated over the first so that when the two films are joined, they stick together and trap the air in the bubbles.

Multiple layers of bubbles may be joined together if desired to produce a thicker sheet of bubble material having a three-dimensional network of bubbles.

The plurality of air-containing pockets in the bubble material provide natural buoyancy to the material. Preferred materials are polyethylene bubble material or any other material known in the art for use in bubble swimming pool covers.

Preferably, the lower layer is a heat absorbing and/or light absorbing layer. This has the advantage of absorbing solar energy passed through the top layer and retaining it in the blanket so that a greater proportion of the incident energy is ultimately transferred to the water in the gap between the layers. It is also advantageous as it increases the insulating effect of the cover.

The heat absorbent layer may be a dark layer, and is preferably composed of a dark coloured material, more preferably a dark coloured plastic layer. In most preferred embodiments the lower layer is a dark coloured bubble material.

As used herein, the terms upper' and lower' layer refer to the relative position of the layers when the blanket is in use i.e. when it is floating on the surface of a pooi. The upper layer is the layer on top which is exposed to incident light. The lower layer is closer to the pool and may be in contact with the pool water.

The upper and lower layers of the blanket define between them a channel for passage of pool water. Preferably the channel has an inlet for entry of water into the channel and an outlet for exit of water from the channel. The inlet may be an opening or aperture, through which unheated pool water can enter the channel and the outlet is preferably a further opening, through which the heated water can exit the channel, to be returned to the pool. However in some embodiments the inlet and outlet may be provided by a single opening. The channel is preferably shallow enough to provide a thin layer of water between the blanket layers, such that heating of the water when in the channel is effected more quickly.

When the blanket is in use, the water in the channel is heated by solar energy incident on the top surface of the blanket, which passes through the top layer into the channel.

In preferred embodiments, the channel allows continuous circulation of water from the pool, through the blanket, and back to the pool. In this way the overall temperature of the pool is gradually increased.

To facilitate this circulation of water through the blanket, the channel inlet is preferably connectable to a pump which transfers water from the pool to the channel.

Advantageously, this pump could be the existing pump in the pool filter system. The flow of the water through the blanket need not be continuous, although this may be more convenient if the pool filter pump is used to distribute the water. A slower flow rate may be preferred, for more effective heating.

Typical flow rates for pool filter pumps are known to those in the art and are able to be used in the present invention.

Other means for inducing flow through the channel are also possible. In some embodiments the flow may be assisted by gravity.

In certain preferred embodiments, the heating blanket is connected to a liquid distribution manifold which directs water pumped from the pool into the channel inlet. The channel may then be connected to a pump via the manifold.

In some preferred embodiments, the blanket may have a plurality of channels and/or a plurality of channel inlets, and in these cases the manifold is used to ensure distribution of water into each inlet. In these systems the manifold is connectable to the pump, and the channel(s) can therefore be connected to the pump via the manifold.

The solar heating and heat retaining blanket may be structured and may provide discrete channels or a network of channels through which the water can flow. The relative positions of the channel inlet and outlet can be varied to provide different shapes of channel or, where multiple channels are present, different channel networks.

Whatever the shape of the channel or channels, it is desirable that the water spends sufficient time in the interlayer space to be efficiently heated. Therefore, in embodiments with substantially linear channels it may be preferred to have the channel inlet(s) at a first end of the blanket and the outlet(s) at an opposite end.

As discussed above, it is possible to have multiple channels. In some preferred embodiments the space between the layers is divided into several channels, for example by waterproof seams. The seams preferably run along the length of the blanket from a first end, where the channel inlets are situated, to a second end, opposite the first end, where the channel outlets are positioned. In some alternative embodiments the blanket could have seams defining other types or shapes of channel network, with the outlet(s) located in other positions as appropriate. For example, curved, spiral or zig-zag patterned channels could be used.

In some embodiments the channel outlet(s) may flow into a discharge pipe or manifold. Preferably this is a perforated pipe, which may preferably run along an edge of the blanket.

The pipe preferably has openings, which are in fluid communication with the channel, via the channel outlets, and holes or perforations open to the pool, for discharge of the water received from the channel back into the pool.

In some embodiments, the discharge pipe may double as a pull strengthener by providing a resilient edge to the blanket. This can facilitate covering of the pool with the blanket, especially if the blanket is wound on a storage reel.

The discharge pipe serves to strengthen the trailing end of the blanket, to facilitate pulling of the blanket off the reel. In these embodiments the pipe is preferably made of a rigid material. In other embodiments, there may be a separate pull strengthener or resilient edge.

The heater of the first, second, or third aspects of the invention may conveniently be mounted on a storage reel. Such a reel may have a central spindle around which the heating blanket can be wound, due to its flexible nature. The blanket can be spooled off the storage reel, preferably directly onto the pool, when required to cover and heat the pool. It can be wound on to the reel out of the way when the pool is in use. A storage reel for a conventional pool cover may be adapted for use with the heating blanket of the invention.

The blankets of the heaters according to the invention could be rolled up manually when not in use and therefore a storage reel is not essential, although it is preferred.

Apparatus for feeding pooi water into the blanket, such as a manifold or a hose, may be incorporated into the blanket itself and may be connectable to the pool filter pump.

Alternatively a hose or manifold, connectable to the blanket and to the pump, may be included in a separate piece of apparatus. In other alternative embodiments, the blanket may be mounted on a conventional storage reel, and apparatus for piping pool water into the blanket may be installed separately, either on the reel or elsewhere, and connected to the blanket.

The heaters of the first, second or third aspects may alternatively be used with a storage reel according to the fourth aspect of the invention, as described below. Preferably the storage reel on which the heating blanket is mounted is positioned at an end of a swimming pooi to be heated.

A fourth aspect of the present invention provides a swimming pool heater including a flexible, buoyant blanket mounted on a storage reel, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers to receive pool water to be heated, wherein the storage reel includes a liquid distribution manifold connected to the channel, for transferring water from the pool into the channel The blanket may be a heating blanket according to the first, second or third aspects of the invention.

The distribution manifold may be in the form of a hose or pipe that runs along the length of the reel spindle. In some embodiments the reel may be dual-purpose' and the spindle may be a pipe, connectable to the pump and to the channel, and hence serve as a manifold.

The storage reel is preferably positioned at an end of a swimming pool to be heated.

A fifth aspect of the invention provides a swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers to receive pool water to be heated, wherein the channel has an inlet for entry of water to the channel and an outlet for exit of water from the channel, and having support means, to raise the inlet relative to the outlet, to allow a gravity-assisted flow of water through the channel, wherein part of the blanket is connectable to the support means such as to enable raising of the inlet.

The blanket of the fifth aspect of the invention is preferably a heating blanket according to the first, second or third aspects of the invention. It is preferred that the channel inlets are raised relative to the channel outlets, so that the flow of water through the channel is assisted by gravity. In some embodiments a distribution manifold may be connected to the channel inlets. In these embodiments it is therefore preferred that the manifold is higher than the pooi surface.

The support means is preferably a storage reel on which the blanket is mounted. The swimming pool heater of the fifth aspect may also be mounted on a storage reel including a distribution manifold, as described in the fourth aspect of the invention. In these embodiments, it is preferred that the storage reel is above the pool surface.

The present invention also relates to methods of installing swimming pool heaters and kits for such installation. A swimming pool heater according to the present invention may be installed on any swimming pool. A flexible buoyant blanket, such as that described in relation to any of the first to fifth aspects of the invention, may be placed onto the surface of the pool, such that the upper layer of the blanket is uppermost and is exposed to sunlight when the blanket is in use. Alternatively the installation may involve mounting the blanket adjacent to the pool, in such a way as to be easily movable onto the surface by a user. For example this could involve mounting the heating blanket on a storage reel adjacent to the pool such that it can be spooled off the reel directly onto the pool, in the correct orientation.

Accordingly, a further aspect of the invention is a method of installing a heater according to the first aspect of the invention, including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is transparent and at least one of the layers is composed of a bubble material; and b) connecting the channel to a pump to transfer water from the swimming pool into the channel.

A still further aspect provides a method of installing a heater according to the second aspect of the invention for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer of a bubble material, a lower layer of a bubble material, and a channel between the upper and lower layers for passage of pool water to be heated; and b) connecting the channel to a pump to transfer water from the swimming pooi into the channel.

Another aspect of the invention is a method of installing a heater according to the third aspect, including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is composed of a bubble material; b) connecting the channel to a pump to transfer water from the swimming pool into the channel.

Another aspect provides a method of installing a heater according to the fourth aspect. This includes the steps of a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, the channel having an inlet for entry of water to the channel and an outlet for exit of water from the channel; b) providing support means to raise the inlet relative to the outlet; c) connecting part of the blanket to the support means such as to enable raising of the inlet; and d) connecting the channel to a pump to transfer water from the swimming pool into the channel.

In some preferred embodiments, these methods may include the further step of connecting the pump to a liquid distribution manifold, which is connected to the channel.

A still further aspect is a method of installing a heater for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, b) mounting the blanket on a storage reel including a liquid distribution manifold connectable to the channel; and c) connecting the channel to a pump via the manifold, to transfer water from the swimming pool into the channel.

In each of these methods, the pump to which the channel is connected is preferably the filter pump of the swimming pool.

A kit of parts may also be provided containing a heating blanket according to the invention and other components for installing the heater on a pool, such as a storage reel and/or a liquid distribution manifold for connection to a pump, which may be the pool's own filter pump.

Accordingly a further aspect of the present invention is a kit for assembly of a heater, such as a heater according to the first, second or third aspects, comprising a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein at least one of the layers is a bubble material; and b) a storage reel; wherein the blanket is mountable on the storage reel.

Another aspect is a kit for assembly of a heater, such as a heater according to the fourth aspect of the invention, comprising a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, the channel having an inlet for entry of water to the channel and an outlet for exit of water from the channel; and b) support means for raising the inlet relative to the outlet, to allow a gravity assisted flow of water through the channel; wherein part of the blanket is connectable to the support means such as to enable raising of the inlet.

Preferably these kits also include a liquid distribution manifold.

A further aspect of the invention provides a kit for assembly of a heater, such as a heater according to the fifth aspect of the invention, which includes a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated; and b) a storage reel including a liquid distribution manifold connectable to the channel; wherein the blanket is mountable on the storage reel.

Note also that the fact that water panels between the upper and lower layers of the blanket should improve the longevity of the blanket.

Embodiments of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a blanket according to an embodiment of the invention in use on a swimming pool; Figure 2 is a plan view of a blanket according to an embodiment of the invention covering a swimming pool; Figures 3 and 4 show cross-sections of a blanket with storage reel, according to an embodiment of the invention.

An example of a heating blanket 1 for a swimming pool 2 according to an embodiment of the invention is shown in Figure 1. The blanket 1 is mounted on a reel 3 and can be wound around this reel for storage when not in use as a swimming pool cover. The reel 3 also includes a hose or manifold 4, for distributing pool water 16 to be heated into the blanket.

The blanket 1 shown in Figures 1 to 3 has two layers of bubble material defining a space or channel 5 between them which serves as a conduit for the pool water 16. Arrows show the direction of flow of the pool water. Water from the pool 16 is pumped into the manifold 4 and then flows from the manifold 4 into the gap 5 between the blanket layers. The pool water 16 then flows through the blanket, out of outlets 14, and is eventually returned to the pool via a discharge pipe 6.

Heating of the water occurs while it is in the space 5 between the blanket layers.

Pumping of the water into the manifold can advantageously be achieved using an existing pump 15 such as that in the swimming pool filter system. Re-circulated water 16 from the pool filter can be fed into the manifold 4 for distribution between the blanket layers.

If the hose reel 3 is raised relative to the surface of the pooi 2, as shown in Figures 1 and 4, the water may flow through the blanket under gravity. Alternatively or additionally the flow of water through the blanket channel is driven by the pumping action. Other means of ensuring a flow of water are also possible. Figures 1 and 4 show discharge pipe 6, situated at the end of the blanket opposite the reel end, through which the water can exit the blanket, via outlets 14, and return to the pool. Outlets 14 may be an opening or openings at the end of the channel. In the example shown, the discharge pipe 6 is about 50mm in diameter. Preferably the discharge pipe 6 is a perforated pipe.

Heating of the pool water 16 occurs as it flows through the blanket by means of the solar energy 7 incident on the blanket.

The upper layer 8 of the blanket 1 is translucent to allow solar energy to penetrate to the water in the gap below.

In the embodiment shown in Figures 1, 3 and 4, the upper (outer) layer is a translucent bubble material such as a translucent polyethylene bubble material. As well as adding to the buoyancy of the blanket, the bubbles 10 in the translucent top layer act like a lens, to focus and magnify the sunlight.

This increases the heating effect of the incident sunlight.

The lower layer 9 of the blanket 1 is also composed of a bubble material, as shown in Figures 1, 3 and 4. In these preferred embodiments the bubbles in the lower layer provide buoyancy to the blanket. The lower (inner) layer may be heat and/or light absorbent, for example a dark, heat-absorbent bubble material. This provides better insulation for the bulk of the swimming pool, as well as trapping the incident radiation for transfer to the water flowing in the blanket, thereby improving the heating efficiency.

A preferred blanket structure is shown in Figure 2, in which the blanket 1 is in place covering a typical 16 x 32 foot (4.9 x 9.8 m) pool. This blanket has waterproof seams 13, which are preferably about 600rrun apart, running laterally along the length of the blanket to ensure the passage of water through the blanket. The seamed structure is shown in more detail in Figure 3.

In the embodiment shown, the seams define several discrete channels 11, which run along the length of the blanket 1, from the reel end to the opposite end, where the discharge pipe 6 or other outlet is located. The manifold 4 in the reel 3 distributes water pumped from the pool into the channels 11. The channels 11 all run into a single discharge pipe 6 through which the water is then returned to the pool.

Alternatively each channel could have a separate outlet 14 directly to the pool 2.

As mentioned above, and as shown in Figures 1 to 4, the blanket 1 may be mounted on a storage reel 3 which may also include apparatus to pipe the pool water into the gap 5 between the blanket layers. For example this apparatus may be a water distribution manifold 4 which preferably runs along the length of the storage reel 3. The water may then be distributed from openings at appropriate points along the manifold, for example, as shown in Figure 2, water may be piped through the manifold 4 and enter the inter-layer channels 11 via openings 12 connected to each channel.

The blanket 1 is attached to the storage reel 3 so that it can be spooled onto and off the reel for ease of storage and deployment.

Use of a blanket as described above reduces pool heating costs and avoids the need for expensive electric heaters or heat pumps.

Claims

CLAIMS: 1. A swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pooi water to be heated, wherein the upper layer is translucent and at least one of the layers is composed of a bubble material.
2. A swimming pool heater including a flexible, buoyant blanket having an upper layer of a bubble material and a lower layer of a bubble material and a channel between the layers for passage of pool water to be heated.
3. A swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is composed of a bubble material.
4. A swimming pool heater according to claim 1, wherein the upper and the lower layer are each composed of a bubble material.
5. A swimming pool heater according to any of claims 1 to 4, wherein the lower layer is a heat absorbing layer.
6. A swimming pool heater according to any of claims 1 to 5, wherein the channel between the upper and lower layers has an inlet for entry of pool water to the channel and an outlet for exit of pool water from the channel.
7. A swimming pool heater including a flexible, buoyant blanket having an upper layer, a lower layer, and a channel between the upper arid lower layers for passage of pool water to be heated, the channel having an inlet for entry of water to the channel and an outlet for exit of water from the channel, and having support means, to raise the inlet relative to the outlet, to allow a gravity-assisted flow of water through the channel, part of the blanket being connectable to the support means such as to enable raising of the inlet.
8. A swimming pool heater according to claim 6 or claim 7, wherein the channel inlet is positioned at a first end of the blanket and the channel outlet is positioned at an opposite end of the blanket.
9. A swimming pooi heater according to claim 8, wherein the channel outlet is connected to a discharge pipe.
10. A swimming pool heater according to claim 9, wherein the discharge pipe is a perforated pipe.
11. A swimming pool heater according to claim 9 or claim 10, wherein the discharge pipe runs along an edge of the blanket to provide a resilient edge.
12. A swimming pool heater according to any of claims 1 to 11, wherein the blanket has a plurality of channels to receive pool water.
13. A swimming pool heater according to claim 12, wherein the channels are separated by a waterproof seam.
14. A swimming pool heater according to any of the preceding claims, mounted on a storage reel, wherein the blanket is spoolable around the reel.
15. A swimming pool heater according to claim 14, wherein the storage reel includes a liquid distribution manifold connected to the channel for transferring water from the pool into the channel.
16. A swimming pool heater including a flexible, buoyant blanket mounted on a storage reel, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the storage reel includes a liquid distribution manifold connected to the channel, for transferring water from the pool into the channel.
17. A kit of parts for assembly of a swimming pool heater including: a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein at least one of the layers is a bubble material; and b) a storage reel; the blanket being mountable on the storage reel.
18. A kit of parts for assembly of a swimming pool heater including: a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pooi water to be heated, the channel having an inlet for entry of water to the channel and an outlet for exit of water from the channel; and b) support means for raising the inlet relative to the outlet, to allow a gravity assisted flow of water through the channel; part of the blanket being connectable to the support means such as to enable raising of the inlet.
19. A kit of parts according to claim 17 or claim 18 including a liquid distribution manifold connectable to the channel.
20. A kit of parts for assembly of a swimming pool heater including: a) a flexible buoyant blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated; and b) a storage reel including a liquid distribution manifold connectable to the channel; the blanket being mountable on the storage reel.
21. A method of installing a heater for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is transparent and at least one of the layers is composed of a bubble material; and b) connecting the channel to a pump to transfer water from the swimming pool into the channel.
22. A method of installing a heater for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer of a bubble material, a lower layer of a bubble material, and a channel between the upper and lower layers for passage of pooi water to be heated; and b) connecting the channel to a pump to transfer water from the swimming pool into the channel.
23. A method of installing a heater for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, wherein the upper layer is composed of a bubble material; b) connecting the channel to a pump to transfer water from the swimming pool into the channel.
24. A method of installing a heater for a swimming pool including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, the channel having an inlet for entry of water to the channel and an outlet for exit of water from the channel; b) providing support means to raise the inlet relative to the outlet; C) connecting part of the blanket to the support means such as to enable raising of the inlet; and d) connecting the channel to a pump to transfer water from the swimming pool into the channel.
25. A method according to any of claims 21 to 24 including the step of connecting a liquid distribution manifold between the pump and the channel.
26. A method of installing a heater for a swimming pooi including the steps of: a) providing a flexible buoyant blanket to float on the surface of the swimming pool, the blanket having an upper layer, a lower layer, and a channel between the upper and lower layers for passage of pool water to be heated, b) mounting the blanket on a storage reel, the storage reel including a liquid distribution manifold connectable to the channel; and b) connecting the channel to a pump via the manifold, to transfer water from the swimming pool into the channel.
27. A method according to any of claims 21 to 26, wherein the pump is the filter pump of the swimming pool.
28. A swimming pool heater substantially as herein described, with reference to and as illustrated in the accompanying drawings.