GORV - Digital Magazine Issue #24 | Page 23

RV FEATURE monocrystalline modules are more efficient than polycrystalline modules, but the top quality modules are now equal. WHAT CAN I RUN FROM SOLAR? By and large, running from solar is feasible with LED lighting, and a microwave oven run for only a few minutes a day (they typically draw 130 amps at 12 volts). That not feasible is direct electric space heating and water heating on anything but a minor scale. But one can readily install a solar-only hot water heater. The top brands of reverse-cycle air-conditioners are just feasible to run from solar in the larger RVs that have space for the solar capacity required during the day. The top Daiken 2500 watt US7 draws only 420 watts at its maximum cooling capacity, and 600 watts at maximum heating. Dometic’s hatch-replacement Harrier reverse- cycle unit is even more efficient. It is claimed to produce 3.1 kW cooling and 2.8 kW heating for only 6.5 amps at 12 volts (78 watts) and 5.2 amps at 12 volts (62.4 watts) respectively. That is readily feasible with a dedicated 120 amp-hour LiFePO4 battery. LED lighting has long since replaced halogen, or should be if not done already. It works extremely well in older RVs: their lighting wiring was usually less than adequate, but is now virtually (but useful) overkill for the typically ten-times-more- efficient top-brand LEDs. The Philips 7 watt units are particularly suitable for RVs — the warm white version particularly. Final tip: if travelling far north in anything but winter, be aware that solar input is actually lower than (say) Sydney. This is because the irradiation is partially blocked by the high humidity. Worse, it stays hot all night as well… and people have been known to drink more cold beer! EXPERT ADVICE Collyn Rivers is an engineer with a particular interest in recreational vehicles. He has written extensively on most technical matters relating to the field, from correct EXPERT ADVICE caravan weight to solar towing Collyn Rivers is an distribution engineer with a particular dynamics. interest in recreational vehicles. He has written extensively on most technical matters relating and to His websites, www.solarbooks.com www.rvbooks.com, are a weight trove of distribution insightful, the field, from correct caravan practical, to solar towing technical dynamics. information relevant to Australian RVers. These articles are easy His to websites, www.solarbooks.com and www. understand — a degree in rocketry is not needed the rvbooks.com, are — a without trove of ‘dumbing insightful, down’ practical, essential technical aspects. technical information relevant to Australian RVers. Collyn you has are written these articles easy Whether buying a new RV, are want to to understand — look a degree rocketry is unit, not know what to for in a in second-hand needed — without ‘dumbing down’ the we can recommend his websites as essential a source technical aspects. of reliable information. Whether you BOOKS are buying a new RV, want to know SOLAR what to look for in a second-hand unit, we can recommend his websites as a source of reliable WWW.SOLARBOOKS.COM information. SOLAR BOOKS: RV BOOKS www.solarbooks.com WWW.RVBOOKS.COM RV BOOKS: link to www.rvbooks.com / 23