GB2424268A - A moulded modular ridge tile arrangement for solar energy conversion - Google Patents

Abstract

A solar energy collection device consists of a range of moulded modular ridge tiles (10, 11 fig 4). Each tile 1 may include flanged ends 2 and incorporate a tray 5 with an end seal (9 fig 4), and may include at least one pipe 3 carrying a liquid to be heated, or alternatively may include photovoltaic cells. The tile may be coloured to match personal preferences, and made of a glass material which defines a void 8. The void may be coated to maximise heat absorption and minimise heat emission, and where a pipe is used, these can also be similarly coated and arranged to lie on a layer of reflective insulative material to reduce heat loss to the under-tray void 6. The pipe may include suitable connections and seals 4, and the installed tiles may include means to provide leak detection by visual or electronic means. The tray may be flat, elliptical, semicircular, or angled, and the assembled tiles may include a mesh screen 7 to prevent rodent or avian access to the solar heated void.

Description

Solar energy collection device Solar panels for using solar radiation to

heat a liquid, often water, or to provide electricity are well known in the art. The advantages are that it is possible to convert solar radiation into electricity or by heating water directly, commonly for domestic heating purposes, and into hot water which can the stored in an insulated tank or used to augment an alternative source of heat, such as an oil-fired boiler. This is obviously an advantage in countries with a great deal of sun, although advances in design have led to greatly improved efficiency in such systems. Solar panels are typically installed in roofs to gain the greatest possible amount of sunlight but are of course constrained by the alignment of the roof which may not be ideal. Ideally panels are arranged so that the greatest amount of sunlight impinges on them. Roof mounted panels often require a considerable amount of plumbing at an inconvenient part of the roof which may be in use for other purposes, which can add to the expense and complexity of the installation, and hence increase the pay-back time for the system. This has become increasingly a problem where householders convert loft space for accommodation.

Another disadvantage is that the extra weight is typically borne in the centre of a roof rather than at the apex.

The present invention seeks to address some of these disadvantages in that it provides a kit of parts for collecting solar radiation for use in domestic and commercial heating systems so as to improve the efficiency thereof, while also accordingly making a contribution to the world ecology by reducing consumption of fossil fuels, etc. The invention permits the greatest possible solar energy to be collected irrespective of the alignment of the building and accordingly it comprises inter alia modular ridge tile units in a range of standard lengths to enable the solar heating system to be arranged at the apex of a roof so as to maximise the solar gain. The weight is also borne by the strongest part of the roof and this also serves to maximise the head of the system.

According to the invention there is provided a kit comprising a range of modular moulded ridge tile units, each unit comprising means to convert the sun's rays into heat.

The units may be constructed as standard ridge tiles to blend in with local preferences and planning requirements, but in a preferred embodiment of the invention, they are made of a glass material which can be coloured to match personal preferences said material being selected and possibly coated so as to maximise heat absorption, while also preserving aesthetic visual appeal.

In colder climates, the benefit of solar energy collection devices according to the present invention is that they also collect radiant energy from the sun even on cloudy days, which can be maximised by arranging an insulating layer beneath the pipes carrying the liquid to be heated and that the pipes are either appropriately coloured to maximise heat absorption or that they are fitted with a suitable sleeve to achieve the same purpose. The units also incorporate a flat or angled tray to support the piping used to carry the liquid, typically water with additives. Said tray may be cast in place and may have a reflective coating or may be lined with a proprietary insulating material to reflect heat while preventing heat loss into the void below the tray so as to enhance heat build up and transfer to the liquid in the pipe. Newton's law of cooling indicates that the rate of heat loss/gain between two bodies is proportional to the square of the temperature difference between them. Clearly the overall heating effect from radiant, convected and conducted heat on the water in the pipe is highly dependent on the temperature in the void above the tray being as high as possible, hence the use of insulating material to prevent heat loss into the void below the. In practice it has been found that arranging the tray as a semicircular or elliptical canal has the benefit of attracting the greatest possible solar radiation. A suitable chemical coating may also be applied to the interior of the ridge tile units to allow the sun's rays to pass through the material whilst preventing them from being reflected back through the material.

Clearly another advantage of the present invention is that it is also feasible to replace the piping with photovoltaic cells and benefit from a flow of current whilst also ensuring that said cells are protected from the effects of weather, dust, fouling by animals, etc. An additional advantage is that in snow or icy weather, solar panels installed in the centre of the roof may tend to be covered by and retain snow cover whilst those arranged under ridge tile units according to the present invention tend to stay clear, and hence remain operative.

In its simplest form, each unit is fitted with a single pipe arranged so that when fixing two ridge units together, the male end of the pipe can be inserted into the female connector of the adjoining unit. The pipe may be standard copper or galvanised iron but it has been found that plastic pipe and push fit fittings perform well, especially as the flexibility of the plastic pipe allows it to bend readily to accommodate a considerable temperature - and hence expansion - range.

Depending on the plumbing layout, it may be preferred to arrange the piping so that inflow and outflow occur as one end, but the advantage of the system is that is allows for total flexibility, and indeed the pipe may if preferred and access allows be merely inserted from one end and a single length or multiple continuous lengths run along the tray. A major advantage is that it may also be connected to the rest of the heating system at any convenient point.

One major problem with current systems is that of leakage. If it is feared that leakage may occur in a particular installation, guttering may be installed under the piping, Again, this may be in lengths that match the length of the unit or it may be deemed appropriate to fit longer lengths under the piping. It is then possible to affix a drain at a lower end and so detect visually or electronically if there is leakage.

In a preferred embodiment of the invention, the unit is fitted with seals at one end so that when installed, each end of the tray abuts the adjoining tray and a seal is provided there between, so that any leakage then flows to the designated end of the unit, which in this embodiment is shaped so as to form a gully.

Clearly, the greater the surface area of piping presented to solar radiation, the greater the solar gain but tests have shown that providing an insulated reflective surface to the tray allows use of standard coloured plastics pipe. It may also be found apposite to fit mesh guards at intervals to preclude free rodent and avian access to the units.

Whereas the invention hereinbefore described is designed mainly for use at the apex of ridged roofs, it has also been found that where houses typically have flat roofs, such as in the southern Mediterranean countries for example, the units may be installed atop walls, so obviating the unsightly tanks and solar panels commonly used which occupy a great deal of roof space.

In countries where there is a risk of frost, it is usual to use a mixture of water and a suitable anti-freeze and circulate the liquid through a heat exchanger. Where there is a requirement for potable water to be heated, for example when filling or topping up a swimming pool, or for domestic purposes, the present invention allows for said water to be heated but clearly this would require a secondary pipe to be installed with appropriate plumbing and the facility to empty the pipe if there were the likelihood of freezing. As noted above, most solar heating systems use a heat exchanger so as to obviate this problem.

The ridge units may be designed to accommodate all standard roofing, such as slates, pan-tiles, corrugated sheeting, etc. The present invention will now be described for illustration purposes only with reference to the attached annotated drawings wherein Fig. A shows the invention installed as ridge tiles (Al) on a pitched roof, and Fig. B shows the invention installed atop a balcony wall on a flat roofed house.

On installation, and as shown in Fig 3, suitable length units (1) are affixed on the roof ridge (Al) as for normal ridge tiles so that the flanged end (2) of each unit (1) abuts the flanged end (2) of the adjoining unit. The male end of the internal pipe (3) is located to fit a female push-fit fitting (4) of the adjoining unit and the units fixed in place with suitable grouting or sealant so as the preserve the fluid integrity of the tray (5) and to prevent ingress of rain, etc., through the flanged ends of the modular units.

The pipe (3) or multiples thereof lie on a layer of reflecting insulative material which serves to hinder heat convection to the under-tray void (6) while helping maintain the temperature in the void (8) above the tray. A suitable reflective chemicals coating is applied to the inside of the ridge tile unit so as to prevent radiant heat being reflected out of the void (8). If desired, a mesh screen (7) may be fitted to prevent rodent and avian access to the void (8). Quite apart from other considerations, it is clearly undesirable to have animals gnawing or pecking at relatively soft plastics pipes and fittings, and seals/insulation. As in Figure 4, a seal (9) is provided at one end of the tray (5) to ensure that water ingress is contained and detected without causing damage.

The kit provides suitable end units (10) and angled units (11).

The chief advantage of the present invention is that it allows for a flexible approach to solar heating, while maximising the benefit of radiant, convected and conducted heat irrespective of the alignment of the ridge or wall upon which it is installed and without having to have expensive, heavy and unsightly panels fitted to roofs. In some conservation areas, such panels may be precluded for planning reasons. Ridge tile units according to the present invention can easily be designed to accord with local aesthetic sensibilities and planning requirements. They are quick and easy to install and make best use of an area of the roof which is typically unused, even with the current penchant for converting the loft spaces of domestic housing for accommodation purposes.

Claims (7)

1. Claims: 1. A kit comprising a range of modular moulded ridge tile units,

   each unit comprising means to convert the sun's rays into heat.
2. 2. A kit according to Claim 1 wherein the ridge tiles are coloured.
3. 3. A kit according to either of Claims 1 or 2 wherein the tile additionally comprises a flat, semicircular, elliptical or angled tray.
4. 4. A kit according to Claim 3 wherein the tray comprises a reflective coating on insulating material.
5. 5. A kit according to Claims 3 or 4 wherein the tray is semicircular or elliptical.
6. 6. A kit according to Claim 1 and substantially as set out in the accompanying drawings.
7. 7. A kit according to Claim 1 wherein the interior of the ridge tile units has a coating to prevent heat from being re-radiated through said units.