Hausi99
2021-03-04 10:21:18
- #1
Good day.
The Drinking Water Ordinance Din 1988 200 states that systems with 2 units or more must operate with 60 degree hot water (also with modern fresh water stations).
However, clause 9.7.2.3 allegedly allows a way out for larger systems that want to operate below 60 degrees hot water (example hot water 55 degrees, circulation 50 degrees, multi-family house with 5 residential units).
Central drinking water heaters with high water exchange:
If during operation a
water exchange in the drinking water installation for hot drinking water within 3 days is ensured,
operating temperatures can be set to 50 °C. Operating temperatures < 50 °C are to be avoided. The operator must be informed during commissioning and instruction about the possible health risk (Legionella proliferation).
Does this mean that a large system (e.g. 5 residential units) may operate with e.g. 55 degree hot water, which ensures a hot water exchange within 3 days?
Is it sufficient here if all residents confirm this to each other?
Within the framework of energy-saving operation, generating hot water below 60 degrees makes sense.
(PS: A Legionella should not care whether the hot water is produced at 55 degrees or 60 degrees. This temperature range prevents spread, but not absolute killing. Also, the risk of contracting Legionella from a fresh water station is rather low if a regular hot water exchange is ensured.)
Are there any practical experiences here?
Thank you very much!
The Drinking Water Ordinance Din 1988 200 states that systems with 2 units or more must operate with 60 degree hot water (also with modern fresh water stations).
However, clause 9.7.2.3 allegedly allows a way out for larger systems that want to operate below 60 degrees hot water (example hot water 55 degrees, circulation 50 degrees, multi-family house with 5 residential units).
Central drinking water heaters with high water exchange:
If during operation a
water exchange in the drinking water installation for hot drinking water within 3 days is ensured,
operating temperatures can be set to 50 °C. Operating temperatures < 50 °C are to be avoided. The operator must be informed during commissioning and instruction about the possible health risk (Legionella proliferation).
Does this mean that a large system (e.g. 5 residential units) may operate with e.g. 55 degree hot water, which ensures a hot water exchange within 3 days?
Is it sufficient here if all residents confirm this to each other?
Within the framework of energy-saving operation, generating hot water below 60 degrees makes sense.
(PS: A Legionella should not care whether the hot water is produced at 55 degrees or 60 degrees. This temperature range prevents spread, but not absolute killing. Also, the risk of contracting Legionella from a fresh water station is rather low if a regular hot water exchange is ensured.)
Are there any practical experiences here?
Thank you very much!