Anti-freeze valves in heat pump systems play a key role in protecting the system from damage caused by the medium freezing. They are an essential component for the proper and trouble-free operation of the system, particularly in the event of a power outage. This article discusses the design, operation, and installation of anti-freeze valves from the perspective of a heat pump installer.
How anti-freeze valves work
IW anti-freeze valves in heat pump systems begin to operate when the ambient temperature drops below 0°C. When the temperature falls to -3°C, the valve opens, allowing the medium to drain and preventing it from freezing. The valve operates proportionally to the temperature decrease—the lower the temperature, the greater the flow of the medium. When the temperature reaches 4°C, the valve closes, eliminating the need for additional medium consumption and minimizing losses. The IW anti-freeze valves offered by Dambat are designed for installation in systems using monobloc heat pumps. Their purpose is to eliminate the risk of the medium thickening and freezing in the system at sub-zero temperatures, which may occur, for example, as a result of a power failure. Why is the role of an anti-freeze valve for a heat pump so important? If the medium freezes, the resulting ice may damage the heat exchanger or other system components, and repair costs in such a situation can be very high.
Although anti-freeze valves are relatively small components with a fairly simple design, their role is nevertheless enormous. Therefore, it simply does not pay to forgo installing this component, whose cost is very low compared with the expenses that would have to be incurred if the system were damaged.
Design of anti-freeze valves
The anti-freeze valves available from Dambat have a simple design but are incredibly effective. They consist of three elements: a body, an insert, and a foot valve. The brass body ensures high durability and corrosion resistance, guaranteeing a long service life. Thanks to their modular design, IW valves can be replaced quickly and easily, which is a significant advantage for installers.
Importance of correct installation
Installing anti-freeze valves is a simple process, but it is crucial to their effectiveness. It is recommended to install valves on both the supply and return lines of the heat exchanger. It is important to install them in locations most exposed to low temperatures, while avoiding proximity to heat sources that could interfere with their proper operation. Correct installation in a vertical position with the outlet facing downward allows the medium to drain optimally. Importantly, anti-freeze valves for heat pumps operate only when the temperature changes, ensuring reliable and tight shutoff. They do not affect pressure and remove only the minimum amount of water required to prevent potential damage caused by the medium freezing.
The anti-freeze valves for heat pumps offered by Dambat can be replaced quickly and easily thanks to their three-part design, with a foot valve positioned between the body and the insert. Both the body and the thermal element of IW valves are made of brass.
Anti-freeze valve variants and specifications
Anti-freeze valves are available in three basic variants, differing in connection diameter: 1ʺ, 1¼ʺ, and 1½ʺ. The maximum flow rates of these valves are 166.7 l/min, 266.7 l/min, and 416.7 l/min, respectively. The maximum drain flow in each variant is 16.7 l/min, which is sufficient to protect the system from freezing. The operating range (medium) is 0ºC–65ºC, while the operating range (external temperature) is -30ºC–65ºC. The valve opens fully at 1ºC, and the closing temperature (medium) is 4ºC. The maximum pressure is 8 bar.
Installation recommendations
Anti-freeze valves should be installed with appropriate clearances, both from one another and from the ground. The horizontal distance between the valves should be 15 cm, while the vertical distance from the bottom of the valve to the ground must also be at least 15 cm. Proper valve placement will ensure effective drainage of the medium when the temperature drops, thereby providing optimal protection for the system.
