efficiency_now:immediate_measures:technology:showerhead
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| efficiency_now:immediate_measures:technology:showerhead [2022/08/24 11:28] – [Background: Legionella] wfeist | efficiency_now:immediate_measures:technology:showerhead [2022/08/24 11:58] (current) – [Protection with high-quality legionella filter] wfeist | ||
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| ==== Protection with high-quality legionella filter ==== | ==== Protection with high-quality legionella filter ==== | ||
| - | Now the latest filter technology can be used for protection against legionella exposure: using microfilters with opening cross-sections considerably less than 0.2 µm, it is possible to eliminate microbes which are larger than 1 µm. These are available as so-called " | + | {{ : |
| We tested one such shower head with regard to practical application: | We tested one such shower head with regard to practical application: | ||
| - The shower head comes with a built-in filter and in appearance is no different from a modern " | - The shower head comes with a built-in filter and in appearance is no different from a modern " | ||
| - It can easily be screwed on to a standard shower hose connection in place of the existing shower head. It works immediately and with a perfect result, the new shower head fits tightly. However, it might be advisable to renew the shower hose as well in any case, particularly if it is already a couple of decades old. | - It can easily be screwed on to a standard shower hose connection in place of the existing shower head. It works immediately and with a perfect result, the new shower head fits tightly. However, it might be advisable to renew the shower hose as well in any case, particularly if it is already a couple of decades old. | ||
| - We took this opportunity to measure the flow rate of the shower with a 10 litre bucket: at the middle position of the faucet (where there is a hooking point, so it is easy to reproduce such an adjustment), | - We took this opportunity to measure the flow rate of the shower with a 10 litre bucket: at the middle position of the faucet (where there is a hooking point, so it is easy to reproduce such an adjustment), | ||
| - | - Showering with this is no different from the previously used shower head: the shower | + | - Showering with this is no different from the previously used shower head: the shower feels ' |
| - | Compared to frequently found shower heads with 12 l/min, water consumption can be reduced by around | + | Compared to frequently found shower heads with 12 l/min, water consumption can be reduced by around |
| - | In single family houses a very high level of safety can be assumed due to the terminal filter((The manufacturer provides proof for a retention factor of 107. Extreme values for contamination in DHW systems with high exposure were less than 106 CFU/ | + | In single family houses a very high level of safety can be assumed due to the terminal filter((The manufacturer provides proof for a retention factor of 10< |
| - Much as we would desire it, it is definitely **not possible to achieve "zero risk" | - Much as we would desire it, it is definitely **not possible to achieve "zero risk" | ||
| - | - However, such " | + | - However, such " |
| - | - The discussion on Corona prevention lies **at the other extreme** of the risks still considered acceptable: apparently around 100 deaths each day in Germany (that would be 44 per 100,000 people per year) are regarded as acceptable (we refer to this as 'risk standardised for 100.000 persons, r in a-1'). For comparison: in 2019 the number of fatalities in road accidents was about 4 per 100,000 people per year. The maximum estimates of the present situation relating to cases of legionnaire' | + | - The discussion on Corona prevention lies **at the other extreme** of the risks still 'considered acceptable': apparently around 100 deaths each day in Germany (that would be 44 per 100,000 people per year) seem to be regarded as 'acceptable' |
| - With the **prevention measures** which we have proposed in various areas, the respective figures can be reduced by more than **four times** (but not to zero!): e.g. legionnaire' | - With the **prevention measures** which we have proposed in various areas, the respective figures can be reduced by more than **four times** (but not to zero!): e.g. legionnaire' | ||
| - | - Other measures might possibly further reduce the risk slightly, but again, not to zero, unfortunately. Thus the consistent use of **bicycle helmets** would perhaps bring down the related standardised risk to 0.02 a-1 and we would also endorse this in view of the low effort for this. The additional increase in the hot water temperatures to above 60°C generally everywhere in the system (beyond the terminal filter) in contrast would achieve a barely measurable improvement because the residual risks that still exist in this area now come mainly from the standing heated cold water (standing water that has now cooled down??? ); However, the effort here is huge because the heat losses are doubled. Likewise, with an additional increase in the air change rate (to 0.8 h-1, as often suggested), the radon concentrations would hardly be measurably reduced any further because according to the available measurement results with a correctly dimensioned heat recovery ventilation system, the values are already close to those of the outside air concentrations; | + | - Other measures might possibly further reduce the risk slightly, but again, not to zero, unfortunately. Thus the consistent use of **bicycle helmets** would perhaps bring down the related standardised risk to 0.02 a<sup>-1</ |
| - | - In contrast, improved infection prevention measures for example have been proven to be able to minimise the COVID risk by a factor of 4 to below 11 a-1 (wearing of masks). Or, pedestrian safety can be improved by a factor of 2 by means of speed regulation in inner cities. In these areas with a still high risk, the effort for further reductions is quite small. | + | - In contrast, improved infection prevention measures for example have been proven to be able to minimise the COVID risk by a factor of 4 to below 11 a<sup>-1</ |
| - | )) | + | )). |
| The terminal filter inside the shower head is simply much more effective for preventing legionella exposure than permanent thermal disinfection. | The terminal filter inside the shower head is simply much more effective for preventing legionella exposure than permanent thermal disinfection. | ||
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| Water-saving shower heads are available on the market at the same prices as conventional ones. With the lack of information for most products, the only trouble is finding suitable shower heads which make a comfortable showering experience possible also with lower flow rates. | Water-saving shower heads are available on the market at the same prices as conventional ones. With the lack of information for most products, the only trouble is finding suitable shower heads which make a comfortable showering experience possible also with lower flow rates. | ||
| - | Extra filter costs of around 100 €/a may well be incurred for a terminal legionella filter. However, the saved energy costs alone are about 125 € each year, and in addition approximately | + | Extra filter costs of around 100 €/a may well be incurred for a terminal legionella filter. However, the saved energy costs alone are about 125 € each year, and in addition approximately |
| - | What matters much more is the fact that such a solution allows operation of the hot water system with a commercially available hot water heat pump as well. According to our assessment, it would be reasonable to aim for a rapid switch to shower heads of the quality described here; this would reduce the number of illnesses in this connection as well as the energy consumption and thus also CO2 emissions. At the same time, the switch to heat pumps (largely renewable energy based systems) for domestic hot water will also be enabled in this way in the medium term. | + | What matters much more is the fact that such a solution allows operation of the hot water system with a commercially available hot water heat pump as well. According to our assessment, it would be reasonable to aim for a rapid switch to shower heads of the quality described here; this would reduce the number of illnesses in this connection as well as the energy consumption and thus also CO< |
| - | [[planning: | + | [[planning: |
| - | Or to the overview relating to the [[planning: | + | Or to the overview relating to the [[planning: |
| ===== References ===== | ===== References ===== | ||
efficiency_now/immediate_measures/technology/showerhead.1661333303.txt.gz · Last modified: by wfeist