What is Water Thermal Expansion? ｜Aquasky
All type of liquid has an expanding volume due to the heat including water. In a closed-loop, water volume increased due to the heat transfer. The extra volume also increases the water pressure. In our house, in every tank-type water heater, cold water is heated as it enters the water heater tank. This increases the overall water volume and pressure inside the tank, which must be relieved to avoid the potentially negative effects of thermal expansion.
For example, water heated from 30°C to a thermostat setting of 80°C in a 180 Liters water heater will expand by almost 6 Liters. Since water is not compressible, the extra volume created by expansion must go somewhere otherwise the water pressure can break the safety volume or the water heater.
In the past, domestic hot water systems were “open” systems. So when the volume of heated water exceeded tank capacity, it flowed back out to the city main or water well.
But today’s plumbing regulations require the integration of backflow preventers or check valves, primarily to keep the water in a home from the possibility of contaminating the water supply. As a result, present-day hot water systems are considered “closed” systems. Any pressure build-up is essentially trapped in the house.
Using a Thermal Expansion Tank
Thermal expansion is created to solve the problem of water thermal expansion. The diaphragm inside the thermal expansion tank is an extra soft and elastic part. It can elongate by the water pressure which can store the extra water volume due to the water heating. When the water is needed, push the water inside the tank for any usage.
There is another design of loop to solve the water expansion which connects the water heater to the toilet system. The system can direct the water expansion volume to the toilet. However, this type of system keeps flashing or flowing the water out of the house. This is a huge water loss. The thermal expansion tank store these volumes.
Having a Thermal Expansion tank in the system is the most efficient way of solving the water expansion.
How to install a thermal expansion tank correctly?
The thermal expansion tank is installed on the cold water side of the water heater at unless 15” distance. The extra volume of water will go into the thermal expansion tank instead of going to the water system.
How long does the thermal expansion work?
The thermal expansion tank needs to be replaced every 7 years due to the high failure rate of the rubber diaphragm inside the tank which the rubber is losing the elastic due to the heat. The tank MUST be replaced every 7 years.
Aquasky THERMAL-PLUS expansion tank is made with the highest standard of the industries. TP series is the insurance of your home water heater.