Summing up: the vacuum tubes are more efficient in cold, windy or cloudy days. Due to the cylindrical form, orientation system, as may be amended up to 25% of the ideal tilt with no loss of performance. Being more efficient, and justified the price, allow them to justify the investment much faster compared to flat collectors. Read FAQ.
Of the many different types of water heaters on the market, the best hot water system for your home will depend on your situation. Consider the following.
Household size – The number of people living in your home and your water consumption patterns (ie whether you all shower at the same time of day; run the dishwasher, washing machine and bath at the same time) will determine the size of the system you need and help to identify the best system and energy source for your needs.
Cost – The purchase cost and operating costs of your hot water system both need to be considered. The energy used by your water heater will impact on your energy bill for years to come so consider carefully before buying.
Government rebates are also available on some energy-efficient systems.
Space available – In existing homes, it may not be possible to install some systems due to lack of space or a difficult layout.
Existing water heater – Some existing hot water systems can be easily converted to more sustainable types. For example, the best replacement for the old-style ceiling-mounted gravity service is often a roof-mounted solar
the system, as plumbing, usually requires minimal alteration.
Available energy sources – Your choice may also be limited by the available energy sources. Natural gas is not available in some areas and solar energy may not be ideal in cooler climates or shaded areas. The energy source of a hot water system has a large impact on greenhouse gas emissions. Natural gas hot water systems typically generate fewer greenhouse gas emissions than electric storage hot water systems and solar hot water systems can generate even fewer greenhouse gas emissions.
Local climate – Sunny locations with good solar radiation allow solar hot water systems to operate most effectively. In warm climates, there is also less energy needed to raise the temperature of the water storage tanks
if they are located outside, as the difference between the air temperature and the temperature of the hot water is smaller.
The number of emissions generated by your hot water system depends on:
– Greenhouse intensity of the energy source.
– Age and efficiency of the hot water appliance.
– Amount of solar radiation available for solar hot water systems.
– Amount of heat available in the ambient air for heat pump hot water systems.
– Heat lost by hot water storage tanks to the outside air.
– The volume of hot water consumed.
The following recommendations can be used to minimize greenhouse gas emissions:
– Where gas is available and solar access is good, a gas boosted solar water heater will generate the
– Lowest greenhouse gas emissions.
– Where gas is available but solar access is poor, an instantaneous gas system or electric heat pump is usually the best option for small to medium households.
For large households (5 people or more), a gas storage system gives similar performance to an instantaneous gas system at a lower cost. Where gas is not available an electric-boosted solar system or an electric heat pump will minimize emissions.
For multi-residential developments, a large, cost-effective solar water heater can be effectively combined with instantaneous gas boosters in each unit, or a geothermal heat pump could be cost-effective for blocks of five or more units.