Expansion tanks in HVAC systems serve the purpose of releasing pressure created by water expansion whenever it is heated. When water heats up, it expands and applies greater pressure to a closed loop, resulting in a number of problems that would be concerned with safety and efficiency. This is where the expansion tank comes into play, absorbing this additional pressure so the system can work both safely and efficiently.
What is an Expansion Tank?
An expansion tank, normally known as a water expansion tank, is a small tank utilized in the protection of the closed-loop HVAC systems from high pressure resulting from thermal expansion. These tanks normally come installed in hot water heating systems or in domestic water systems, providing a buffer in which to absorb the increased pressure from the expanding water.
It is designed to be two-compartment: one for water from the heating system and the other for compressed air. While the water heats up and expands, it moves into the expansion tank, thus compressing the air. This mechanism allows proper water pressure levels in the system and prevents over-stressing of the system that would lead to leakages, burst pipes, or malfunctioning equipment.
Why is an Expansion Tank Necessary?
Water, unlike gases, does not compress easily. When water in a closed system is heated, the pressure inside of a system increases rapidly. If this pressure is not controlled, it may cause damage to pipes, valves, and other components of the system. Expansion tanks avoid these problems by providing a site for the expanding water to go to, thereby keeping the pressure balance of the system.
With newer, more modern HVAC systems, expansion tanks have become an important safety feature in most residential and commercial properties. In this respect, expansion tanks protect both equipment and structure alike from water damage and system failure, thus allowing more reliable operation of a heating or cooling system.
Types of Expansion Tanks
A variety of expansion tanks have been developed to suit particular requirements for different systems on which they are to be installed. Some of the key types are mentioned below:
Open Expansion Tanks: Typically, this type of expansion tank is used for open-loop kind of systems. They are usually installed at the highest point in the building as they capture the increased pressure that results due to the expansion of water.
Closed Expansion Tanks: These are the most common tanks used in residential and commercial systems today. It is sealed and utilizes a diaphragm or bladder that separates the water from the air; thereby, it does not allow the air to dissolve into the water.
In each of these categories, you will also find variations in size, pressure ratings, and materials based on the system requirements.
Expansion Tanks in Domestic Water Systems
They are not only important for HVAC systems but also play a vital role in domestic water systems, especially those connected to water heaters. As the water in a hot water tank is heated, the pressure inside the system increases. Without an expansion tank, the pressure could be pushed back into the plumbing, wearing out valves, faucets, and other fixtures excessively. A good water pressure tank works with water heaters to maintain a balanced pressure to avoid exerting unnecessary pressure on plumbing systems.
For homes where water heaters are installed without any expansion tanks, there are problems such as leaky faucets, burst pipes, and a lot of noise in plumbing caused by increased water pressure.
Choosing the Right Expansion Tank
The selection of an appropriate expansion tank is vital to its performance. A few considerations involve things like the following:
System Pressure: You have to choose an expansion tank with regard to the pressure within your HVAC or water heating systems that it is meant to operate. The tank should be rated at a pressure compatible with your system operating pressure.
Tank Size: It ranges according to the size of the system it is installed within, which includes the volume of water inside it. A small system may be adequately served with a small tank, but an extensive commercial HVAC will require a much bigger one in order to accommodate expanding water.
Material: Depending on the various factors, for example, on the quality of water within the system, as well as the operating environment of the system, expansion tanks can be made of steel, among other composite materials.
Installation Location: This is an area through which maintenance for the expansion tank should find it easy; hence, installation must be made in accessible areas near the water heater or boiler.
Maintenance and Longevity
Expansion tanks are long-lasting parts but must undergo regular servicing. After many years, the diaphragm inside of the tank can get damaged and may no longer be able to absorb the pressure inside of the tank. This is taken care of by draining the tank and replacing or servicing it before it can cause damage to the system.
Common symptoms that an expansion tank might need servicing include:
Over pressurization of the System: This is when higher than normal system pressure is measured. In most cases, it could mean the malfunctioning of the expansion tank. The discharge of water by the pressure relief valve will indicate there is something wrong with the expansion tank, as it fails to dissipate the pressure, hence a discharge of water in order to cool the system down. Knocking Sounds: These are usually because of the failure of the tank to absorb the pressure, which travels through the pipes.
It is, therefore essential that these signs are noted and that the scheduling of periodic inspections serves as a preventive measure against system failures.
Conclusion
Expansion tanks should be the central component of every HVAC and hot water heating systems. They ensure a smooth and safe operation of these systems by regulating pressure through the accommodation of expanding water as a cushion. Whether it is an expansion water tank or the best water pressure tank , a good quality and size-appropriated expansion tank alone can increase the life of HVAC or a water system, reduce repairs, and protect your homes or businesses from expensive damages.
The Zealux Group deals in the supply of quality accessories for HVAC systems, built on over 20 years of experience in R&D and manufacturing. From expansion tanks to other related complementary components, we commit our products to quality through your very peculiar system requirements.