[{"id":455,"date":"2017-06-30T07:22:35","date_gmt":"2017-06-30T07:22:35","guid":{"rendered":"http:\/\/atonengineering.co.nz\/aton-gallery\/"},"modified":"2017-06-30T07:22:35","modified_gmt":"2017-06-30T07:22:35","slug":"aton-gallery","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/aton-gallery\/","title":{"rendered":"Aton Gallery"},"content":{"rendered":"
Solar water heating is an age old activity and to a first approximation one can say about it that “There is nothing new under the sun”.<\/span><\/p>\n Collectors<\/b><\/span><\/p>\n In New Zealand almost all commercial solar water heaters are variants on the so called flat-plate tube-on-sheet collector. In these devices a blackened flat sheet of metal intercepts the sunlight. The heat is then transmitted to a set of tubes which are attached to the plate and in which the water being heated flows. Header pipes bring the water to the tubes and collect it from them. The absorber is enclosed in an insulated case with a transparent cover to create a complete solar panel.<\/span><\/p>\n Until about twenty-five years ago the absorber sheet was almost always made entirely of copper which is one of the best thermal conductors known. However price increases in copper began to make such collectors too expensive and the attention of designers turned to ways of achieving good collection efficiencies with cheaper materials.<\/span><\/p>\n Unfortunately there is nothing like copper for corrosion resistance in the actual waterways and even now most solar water heaters still have copper water pipes.<\/span><\/p>\n The next best readily available conductor for the sheet is aluminium whose conductivity, while not as good as that of copper, is still quite good. To offset the lower conductivity of aluminium one needs to use a thicker sheet or to put the tubes on the collector closer together. Both of these measures tend to offset the initial savings achieved by going away from a copper sheet. There are however a couple of other tricks which have been used to counteract the lower conductivities of metals other than copper.<\/span><\/p>\n Selective Coatings<\/b><\/span><\/p>\n One of these tricks is “selective coating”. In selective coating a thin layer of either finely divided nickel (black nickel) or chromium (black chrome) is formed on the surface usually by electrolysis. Such a layer has the property that it absorbs solar energy almost as well as a matt black surface but it is a poor emitter of energy at the temperature of the base metal. The net result is that, other things being equal, a selectively coated absorber exposed to sunlight will get hotter than a simple matt black one. This in turn means that the lower conductivity of an aluminium sheet can be compensated by having it run hotter so that the copper water tubes do not have to be put closer together and the sheet does not have to be made thicker. A second advantage of selective coatings is that they enable the collector to work better in poor conditions (weak sunshine), although this is not a major consideration in New Zealand. There are now on the market in New Zealand several collectors which use collector sheets with selective surface coatings.<\/span><\/p>\n For New Zealand conditions, even in the south of the South Island, nearly all solar energy gathering will take place in strong sunshine. This means that the theoretical gains to be had from selective coatings working in weak sunshine are only partially realised in practice. For this reason Thermocell has chosen to use BAC (Broadband Absorbtion Coating) technology for its collector surface. Selectively coated panels also tend to over heat water in strong summer sunshine whereas matte black panels tend to be self limiting. <\/span><\/p>\n Heatpipes<\/b><\/span><\/p>\n Another way of compensating for the poor conductivity of the cheaper materials of construction is to use the so called heat-pipe effect. In a heat pipe, high thermal conductivity is achieved by using the evaporation and condensation of a volatile fluid to carry the heat along an evacuated tube.<\/span><\/p>\n Such a device has a thermal conductivity many hundreds of times that of the same cross section of pure copper. Thermocell has taken advantage of this phenomenon to construct solar collectors of mild steel in which the collector sheet itself is a flat plate version of a heat pipe. This “heat sheet” conducts the heat to the top of the panel where it is transferred in the heat exchanger section to a length of copper tube carrying the water. In addition to its very high thermal conductivity the heat sheet has the further advantage that its conductivity is only in one direction so energy can be transported from the collector sheet to the water tubes but not vice versa.<\/span><\/p>\n From the user point of view both of the methods outlined above make little or no change to the appearance of the collectors.<\/span><\/p>\n View more on Heatpipes<\/a><\/span><\/p>\n <\/span><\/p>\n In-roof collectors<\/b><\/span><\/p>\n There is however another trend which does make a difference to the appearance of solar collectors. This is the design now offered by Thermocell in which the collector is incorporated into the structure of the building. Instead of building solar collectors as independent units which are then mounted on the roof of a house one can build a transparent section (typically glass glazing) into the roof and mount the absorbers in the roof space behind the glazing. In addition to the obvious cosmetic advantages this procedure offers several minor, but significant technical advantages:<\/span><\/p>\n Pumped systems<\/b><\/span><\/p>\n Solar water heating systems are available in simple thermosyphon or pump circulated versions. The thermosyphon arrangement requires no external energy input , but the geometry of the installation is critical in that the cylinder must be above the collector. Pump circulated systems, such as the Thermocell system, are not subject to such constraints, but of course require a small electrical input to the circulating pump.<\/span><\/p>\n The electrical energy used by the circulation pump ends up heating the hot water: the forced circulation of the water through the panels keeps the panels at a lower temperature than if they were in a thermosyphon system. The cooler the panels, the more efficiently they operate (true for any solar panel), and so the pumped system overall is more efficient than a thermosyhon system. <\/span><\/p>\n Heat pumps<\/b><\/span><\/p>\n A final development in water heating, which is not strictly solar but is sometimes set up in a “solar assisted” manner, is the heat-pump. A heat pump is essentially a refrigeration system working in reverse. Instead of pumping heat from an evaporator inside the refrigerator to a condenser in the room the heat pump pumps heat from an evaporator in the atmosphere to a condenser attached to the hot water cylinder. For convenience the evaporator is sometimes mounted on the roof of the house where the sun helps to provide input to the evaporator. Despite the appearance of roof mounted heat pump evaporators, the heat pumps are really electrical heating systems which use electricity in a much more energy efficient way than simple conventional resistance heaters. There is not a lot to distinguish between a good solar system and a heatpump in terms of overall net consumer savings over a year.<\/span><\/p>\n <\/p>\n <\/a>Heatpipes continued<\/strong><\/span><\/p>\n In its simplest form, a heat-pipe (Dunn & Reay 1994) is a sealed tube containing a small quantity of a volatile liquid (such as water) with no air or other “permanent” gas present. If such a pipe is placed vertically and the lower end is heated, liquid will evaporate and the vapour so formed will travel to the cooler parts of the pipe where it will condense and give up its latent heat of vaporisation. The condensate will then run back to the heated end where it can re-evaporate. <\/span><\/p>\n Because the heat transfer within the pipe comes from boiling liquid and condensing vapour, both of which processes have inherently very high heat transfer coefficients, and because the amount of material which has to move from one end of the pipe to the other is small the effective thermal conductivity of the heat-pipe is very large. To illustrate the magnitude of these quantities imagine that the heat-pipe is transmitting one kilowatt using water as the working fluid. The mass flow would be just under 0.5 g\/s. At a temperature of 100 \u00b0C in a 20 mm diameter pipe this would correspond to a vapour velocity of about 2.5 m\/s.<\/span><\/p>\n In more sophisticated versions, the pipe contains a capillary wick to assist the return of the liquid from the condenser end to the evaporator end. Such pipes will work without the aid of gravity, for example in spacecraft. However, for terrestrial applications the far cheaper and simpler two-phase thermosyphon, as the gravity return heat-pipe is usually known, is often adequate.<\/span><\/p>\n The main useful characteristics of the two-phase thermosyphon are:<\/span><\/p>\n (1) the thermal conductivity is extremely high: about a thousand or more times that of copper,<\/span><\/p>\n (2) the thermal conductivity is almost independent of the metal that the heat-pipe is made from,<\/span><\/p>\n (3) the device acts as a thermal diode. That is, the conduction is very high in one direction (upwards) and very low in the other (downwards),<\/span><\/p>\n<\/blockquote>\n These characteristics make heat-pipes useful wherever a large amount of heat needs to be conducted through a small cross-section. They have been used in cooling space-craft components, in cooling plastics-forming dies, for the construction of air-to-air heat exchangers for industrial and domestic energy recovery, and in cooling electronic components mounted in confined spaces. One of the most spectacular applications has been the cooling of the support columns for the trans-Alaska oil pipeline to prevent the melting of the permafrost at their bases.<\/span><\/p>\n Heat-sheets<\/strong><\/span><\/p>\n Thermocell has developed a flat-plate version of the heat-pipe (Foot, Wallace & Williamson 1981a,b) which extends the range of application. The lightweight flat-plate heat-pipe, which we call a “heat-sheet”, consists of two sheets of metal seam-welded together at the edges and carrying a pattern of indentations.<\/span><\/p>\n The indentations create a vapour space within the heat-sheet which is evacuated and into which the working fluid is introduced. The form in which we have used the heat-sheet to date has been as a two-phase thermosyphon. The first commercial application of the heat-sheet is our solar water-heating collector.<\/span><\/p>\n The heat-sheet, made of sheet steel, takes the place of the copper or aluminium absorber sheet of a conventional flat-plate collector. The thermal conductivity is sufficiently high that one only needs a small heat exchanger of copper tube along the upper region of the collector to transfer the collected heat to the water. From a user point of view, the collector is the same as a conventional flat-plate solar collector but is significantly cheaper for a given area of collector. The advantages of this construction are:<\/span><\/p>\n This last feature is a result of the fact that the water-way is at the top of the panel. When water is circulated through the system to protect the waterway from freezing in frost conditions the thermal diode effect means that there is very little conduction from the waterways to the rest of the panel. The remainder of the panel does not require protection since the working fluid has a very low freezing point.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":" Solar water heating is an age old activity and to a first approximation one can say about it that “There is nothing new under the sun”. Collectors In New Zealand almost all commercial solar water heaters are variants on the so called flat-plate tube-on-sheet collector. In these devices a blackened flat sheet of metal intercepts […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/376"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=376"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/376\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":353,"date":"2017-06-29T01:46:21","date_gmt":"2017-06-29T01:46:21","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=353"},"modified":"2017-06-30T05:57:28","modified_gmt":"2017-06-30T05:57:28","slug":"modline","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/modline\/","title":{"rendered":"ModLine"},"content":{"rendered":" ModLine\/ On Roof <\/strong><\/span><\/p>\n Thermocell on-roof, boxed solar panels are the choice for most existing homes. They can be mounted on any roof material using an aluminium frame (which can also be set to mount the panels at the optimum elevation angle for your area), or on mounting brackets for corrugated iron roofs. We manufacture and supply the frame to suit your roof angle and mounting layout.<\/span><\/p>\n Because the panels are the same size as an opened-out newspaper, you can mount the panels in all sorts of ways, should you wish. Indeed, architects have featured the panels in some post-modern designs. <\/span><\/p>\n There is no need to keep the panels together… if necessary, you can mount some panels on one side of a gable and the rest on the other side. You do want to keep the panels more or less within 20 metres of your hot water cylinder.<\/span><\/p>\n View Gallery here<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":" ModLine\/ On Roof Thermocell on-roof, boxed solar panels are the choice for most existing homes. They can be mounted on any roof material using an aluminium frame (which can also be set to mount the panels at the optimum elevation angle for your area), or on mounting brackets for corrugated iron roofs. We manufacture and […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/353"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=353"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/353\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=353"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":351,"date":"2017-06-29T01:46:13","date_gmt":"2017-06-29T01:46:13","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=351"},"modified":"2017-06-30T05:57:42","modified_gmt":"2017-06-30T05:57:42","slug":"artline","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/artline\/","title":{"rendered":"ArtLine"},"content":{"rendered":" ArtLine\/In Roof<\/strong><\/span><\/p>\n Thermocell in-roof solar panels are the choice for new homes. Instead of mounting the solar panels on the roof, you build them into the roof fabric.<\/span><\/p>\n The absorber cores sit on a layer of insulation in a tray built into the roof structure. A skylight type arrangement is mounted over the absorbers. The advantages to the homeowner are that the panels perform a little better than their boxed counterparts (because there is more insulation around them and only one surface is exposed to the weather), and the panels blend in with the lines of the house.<\/span><\/p>\n A little care is needed in the design and framing stages when building the house to ensure that the tray is properly allowed for, but it is not at all beyond the capabilities of a good builder. Thermocell will provide the builder and architect\/designer with the necessary drawings for the installation.<\/span><\/p>\n View Gallery here<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":" ArtLine\/In Roof Thermocell in-roof solar panels are the choice for new homes. Instead of mounting the solar panels on the roof, you build them into the roof fabric. The absorber cores sit on a layer of insulation in a tray built into the roof structure. A skylight type arrangement is mounted over the absorbers. The […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/351"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=351"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/351\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":194,"date":"2017-06-27T04:52:37","date_gmt":"2017-06-27T04:52:37","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=194"},"modified":"2017-06-27T04:52:37","modified_gmt":"2017-06-27T04:52:37","slug":"welcome-to-aton-engineering","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/welcome-to-aton-engineering\/","title":{"rendered":"Welcome to Aton Engineering"},"content":{"rendered":" Founded by Nick Williamson, Aton Engineering offers\u00a0a\u00a0wide range\u00a0of services.\u00a0As well as being the sole manufacturer of \u00a0Thermocell solar hot water systems, Aton Engineering also specialises in a variety of other manufacturing including the\u00a0fabrication of solar frames, repairs to solar water heating panels, aluminium welding, other light engineering including vintage motorcycle parts refurbishment and small parts sandblasting…<\/p>\n","protected":false},"excerpt":{"rendered":" Founded by Nick Williamson, Aton Engineering offers\u00a0a\u00a0wide range\u00a0of services.\u00a0As well as being the sole manufacturer of \u00a0Thermocell solar hot water systems, Aton Engineering also specialises in a variety of other manufacturing including the\u00a0fabrication of solar frames, repairs to solar water heating panels, aluminium welding, other light engineering including vintage motorcycle parts refurbishment and small parts […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/194"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=194"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/194\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":120,"date":"2017-06-27T01:47:34","date_gmt":"2017-06-27T01:47:34","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=120"},"modified":"2017-07-06T04:09:57","modified_gmt":"2017-07-06T04:09:57","slug":"thermocell-products","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/thermocell-products\/","title":{"rendered":"THERMOCELL – Solar water heating"},"content":{"rendered":" No matter how you do the economics, the best time to install any solar hot water system is 5 years ago. Given that this is not usually possible, any time from then up to the present day- and even a little bit into the future- is a good second best.<\/span><\/p>\n Every household uses different amounts of hot water. How much you will save on your electricity bill by using solar hot water heating will depend on how you use the system, the size of your system, and where you live. As a rule of thumb, you can expect to save up to 75% of your hot water bill by using solar energy.<\/span><\/p>\n The financial rate of return is not so easy to calculate- are you comparing the money spent on a solar system to money invested in a bank account? …off a mortgage? …and for how long? You had better include your marginal tax rate in the equation too! All have different interest rates and will give different rates of return. As a general rule, with a return of close to 12% tax free in perpetuity, solar hot water heating is hard to beat. We calculate that a Thermocell solar system has a payback of around 8 years. After that, your summer hot water is free, as is a considerable amount of your winter hot water.<\/span><\/p>\n <\/p>\n New House<\/span><\/strong><\/span><\/p>\n A particularily good time to install solar is when the building is under construction. Installation costs can be kept to a minimum by plumbing and wiring the system before the wall coverings are put up. By designing the house to accommodate a solar system, optimum performance can usually be arranged at little or no effort.<\/span><\/p>\n If the building owner cannot afford to install solar heating immediately, it may be sensible to install a solar hot water cylinder and plumbing at the construction stage to make provision for a future solar system.<\/span><\/p>\n The major advantage of installing solar heating in new buildings is that overall savings in the cost of installation can be achieved by integrating the solar panels as part of the roof structure. This is easliy achieved using our in-roof system<\/a><\/span> where the absorbers effectively fit in underneath standard skylight fittings. <\/span>If you are going to the effort of building a house, we recommend that the design stage is also the best time to look carefully at optimising the building’s overall energy efficiency. <\/span><\/span><\/p>\n <\/p>\n Established Houses<\/span><\/strong><\/span><\/p>\n It is straightforward to install an on-roof<\/a> <\/span>Thermocell solar system into most homes at any time. While your existing hot water cylinder will work just fine, changing it out for a purpose-built Thermocell Sunstore solar hot water cylinder will provide the ultimate in performance. It makes sense to replace your existing hot water cylinder if it was manufactured before 1988 when a much improved hot water cylinder insulation standard was introduced.<\/span><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" No matter how you do the economics, the best time to install any solar hot water system is 5 years ago. Given that this is not usually possible, any time from then up to the present day- and even a little bit into the future- is a good second best. Every household uses different amounts […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/120"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=120"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/120\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":108,"date":"2017-06-27T01:10:41","date_gmt":"2017-06-27T01:10:41","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=108"},"modified":"2017-07-06T04:05:23","modified_gmt":"2017-07-06T04:05:23","slug":"thermocell-faqs","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/thermocell-faqs\/","title":{"rendered":"THERMOCELL – FAQ’s"},"content":{"rendered":" What sort of savings can I expect from a solar hot water system?<\/span><\/b> Is there really a big difference between different brands of solar panel?<\/span><\/b> But you do need to make sure you are comparing like collector areas with like collector areas. At the end of the day, the amount of effective collection area you have is what really matters. Take a look at the <\/span>Consumers’ Instutute article<\/a><\/span> on solar hot water heating, <\/span>also available at EECA<\/a><\/span>, to see the actual performance ratings of different panels. Check also how the panels perform overnight- not for collection, but for losses and for protection.<\/span><\/p>\n …so, why buy Thermocell? The losses our system incurs from overnight cooling- which detracts from overall performance in cooler areas- is particularily low. A panel containing a lot of water or working fluid will take a lot more energy to warm up than a more agile system, such as ours which holds just a few litres of water.<\/span><\/p>\n Our own microprocessor controller and display forms the heart of our frost protection systems. Without boasting, the protection our controller provides is as good as it gets.<\/span><\/p>\n And we did mention that word “reputable”- we have been building and installing our solar panels for over thirty years now and we like to think we deserve our solid reputation.<\/span><\/p>\n Why is a pumped system better than a thermosyphon system?<\/span><\/b> What happens in winter?<\/span><\/b> Is the Thermocell solar system frost-proof? Why don’t Thermocell panels have selective coatings? <\/p>\n Do Thermocell panels corrode?<\/span><\/b> What is the life of a Thermocell solar system?<\/span><\/b> Can Thermocell panels be used in a thermosyphon system?<\/span><\/b> Can Thermocell panels be used in mains or high pressure water systems?<\/span><\/b> Will I run out of hot water? Are all solar hot water cylinders the same? Do I lose performance by going to a glycol loop system?<\/span><\/b> Is glycol safe?<\/span><\/b> Can I run underfloor heating from my solar system?<\/span><\/b> What sort of savings can I expect from a solar hot water system? This is a hard one to answer as each household uses hot water differently. All that can be ever claimed is that on average, over a year you can expect solar to provide 70% – 75% of your hot water. Having said […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/108"}],"collection":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/comments?post=108"}],"version-history":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/pages\/108\/revisions"}],"wp:attachment":[{"href":"http:\/\/atonengineering.co.nz\/wp-json\/wp\/v2\/media?parent=108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}},{"id":100,"date":"2017-06-27T00:04:55","date_gmt":"2017-06-27T00:04:55","guid":{"rendered":"http:\/\/atonengineering.co.nz\/?page_id=100"},"modified":"2017-06-30T05:55:23","modified_gmt":"2017-06-30T05:55:23","slug":"gallery","status":"publish","type":"page","link":"http:\/\/atonengineering.co.nz\/gallery\/","title":{"rendered":"GALLERY"},"content":{"rendered":"\n
\n
\nThis is a hard one to answer as each household uses hot water differently. All that can be ever claimed is that on average, over a year you can expect solar to provide 70% – 75% of your hot water. Having said that, we have had customers who have been (falsely) accused by power companies of tampering with their power meters because their electricity consumption was so low. When doing your sums, you need to be aware that a typical New Zealand household uses about 3,500 – 4,000 kWh\/year of water heating.<\/span><\/p>\n
\nFrom a solar collection efficiency point of view there is not a lot of difference between the panels of reputable manufacturers. You need to be looking at other things such as longevity, street appeal, on-going maintenance costs, equipment price, ease of installation, cost of installation and warranty before you start looking too hard at performance. <\/span><\/p>\n
\n<\/span><\/b>We like to think that the street apeal of our panels is second to none (indeed, trying to find photographs of our in-roof panels that look like panels and not just skylights is very hard); we don’t compromise on performance; it doesn’t get simpler (or cheaper) to install our panels, and there is no maintenance requirement. <\/span><\/p>\n
\nFirstly, a pumped system is more efficient than a thermosyphon system for the same collector area. More importantly for New Zealand conditions, a pumped system allows for true flexibility in building layout- there are no restrictions on the solar panel and hot water cylinder configuration so that the hot water cylinder can be placed for optimum useage and the solar panels for best performance. Thermosyphon hot water cylinders are normally located on the roof and the roof structure may need to be strengthened to accommodate it (under the BIA, hot water storage greater than 300 litres needs a structural report).<\/span><\/p>\n
\nIn the South Island, solar panels will generally not produce a high output water temperature in winter. They will however still provide a significant contribution to your hot water heating when you consider that the cold water inlet temperature will be less than 10\u00b0C. Having said that, we have had a Christchurch customer who found that his hot water cylinder element had been accidently switched off in October, but hadn’t noticed any shortage of hot water until June the next year.<\/span><\/p>\n
\n<\/span><\/b>Yes! The standard Thermocell system is good for areas that experience mild frosts. The Thermocell controller incorporates two panel sensors, one of which is a dedicated frost detectector. Either sensor will trigger the frost protection pump routine. Where prolonged, heavy frosts are experienced we recommend a glycol circuit which can safely withstand any amount of frost. The heatpipe operation of Thermocell panels means that only a small amount of warming water needs to be circulated, unlike conventional solar panels.<\/span><\/p>\n
\n<\/span><\/b>Selective coatings provide improved performance under low light and low ambient temperature conditions, such as to be found in Europe and North America. Most solar collection in New Zealand is under (comparatively) strong light and relatively high ambient temperatures. Our research indicates that the extra effort rquired to add a selective coating to our absorbers is not currently warranted.<\/span><\/p>\n
\nNo! The steel collectors do not come into contact with the circulating water. The panels are phosphate treated and are not exposed to the weather. The glazing arrangement prevents rain ingress. We have had panels installed in the Cook Islands alongside several of our competitors for many years now and we are advised that ours are the only panels that have not rusted. The cases are available in galvanised or power coated. <\/span><\/p>\n
\nWe design and test each panel so that it will be as good in 20 years time as the day it leaves the factory. Having said that, panels that were installed in the early 1980’s are still working just fine.<\/span><\/p>\n
\nNo. The serpentine water-way we use is not suitable for thermosyphon operation.<\/span><\/p>\n
\nYes! Thermocell panels have a unique serpentine waterway which can withstand mains pressure and then some… mains pressure systems operate with a 50 metre head and our panels can withstand in excess of 150 metres of head. <\/span><\/p>\n
\n<\/span><\/b>You are less likely to run out of hot water with a Thermocell solar hot water system than you are with a conventional (i.e. non-solar heated) hot water cylinder. The hot water cylinder and controller designs mean that there is always a reservoir of hot water waiting to be drawn off in the hot water cylinder. Should there have been insufficient sunshine to heat the water to a useable temperature, the electrical heating arrangement will automatically “top up” the temperature.<\/span><\/p>\n
\n<\/span><\/b>You want to make sure that your hot water cylinder is designed for New Zealand conditions. A hot water cylinder optimised for much warmer Australian conditions will have a much higher overnight heat loss than an A-Grade Watermark hot water cylinder designed for our cooler climate. This is especially true if you are going to sit your hot water cylinder on your roof, or in your roof space.<\/span><\/p>\n
\nSadly, yes… any liquid\/metal\/liquid interface introduces thermal resistance. As going to a glycol loop will cost you between 5-10% of your annual performance, this can be offset by an increase in installed panel area and in warmer climates you don’t need a glycol system.<\/span><\/p>\n
\nWhile we don’t recommend drinking it, propylene glycol is safe for humans. Indeed, some years ago a number of European wine manufacturers used to add it to their wine to provide extra flavour. We use glycol loop systems only for New Zealand’s coldest regions and when we tasted it, we thought it rather pleasant! Ethylene glycol as used in automobiles is toxic and should not be used. <\/span><\/p>\n
\nBut why?! There is a very good reason why it is cold in winter and it is directly linked the the amount of sunshine you get (or rather, don’t get) then. Such arrangements will give you hot floors in summer and won’t do much in winter. A simpler and much cheaper way to achieve a better result is to install some skylights of the same area as your panels and let the sun shine onto the floor directly.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"