The Dud Shemesh: An Essential Guide to Israel’s Solar Water Heater
The “Dud Shemesh” is a fundamental appliance in nearly every Israeli home. Understanding how it works and what to look for is important for any renter or homebuyer.
How a Dud Shemesh Works:
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Collector Panel (קולט): This is the flat, dark panel on the roof. It contains a network of pipes. Water flows through these pipes and is heated by the sun’s radiation.
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Storage Tank (הדוד): The hot water then rises (due to thermosiphoning) into the insulated storage tank, which is positioned above the collector.
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Hot Water Supply: The hot water from the tank is then fed into the home’s plumbing system.
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Electric Backup (דוד חשמל): Inside the tank, there is also an electric heating element. On overcast winter days or when hot water demand is high, you can flip a switch inside your apartment to activate this element and heat the water electrically.
What to Check When Buying or Renting:
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Age and Condition: When viewing a property, ask about the age of the Dud Shemesh. They typically have a lifespan of 10-15 years. Look for visible signs of rust or leaks on the tank.
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Private vs. Central System:
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Private Dud (דוד פרטי): Most older buildings have a separate dud for each apartment. This gives you direct control over your hot water.
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Central System (מערכת מרכזית): Many new high-rise towers have a central heating system, often with solar panels on the roof that serve the whole building. In this case, hot water usage is metered for each apartment.
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Maintenance: A Dud Shemesh requires periodic maintenance, primarily to clean out limescale (“avnit”) buildup, which is common with Israel’s hard water. This should be done every few years to maintain efficiency.
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Timer Switch (“Taymer”): Check if there is a timer switch for the electric backup. This is a very useful feature that allows you to heat the water for a set period (e.g., one hour before you wake up) without having to remember to turn it off, saving electricity.
A properly functioning Dud Shemesh is a key money-saving feature of an Israeli home. It’s a simple, eco-friendly technology that is perfectly suited to the Israeli climate.
