Although the regulations do not oblige investors to use a hot water circulation system in single-family houses, sometimes it can be very useful. This solution only slightly increases electricity consumption and in return saves water and significantly increases the comfort of using the hot water installation. The key element of such a system, apart from the additional water return pipe, is the circulation pump . How does such a device work and what should you consider when choosing it?
From this article you will learn:
- what is the circulation pump used for,
- what to consider when choosing a circulation pump,
- what additional functions do circulation pumps have?
- What does the installation of a circulation pump look like?
Circulation pumps for single-family houses – characteristics
It is worth installing a circulation pump in the hot water installation, especially when the draw-off points are located far from the heater or water tank. When using a system without a circulation system, you have to accept the loss of water resulting from waiting for the inflow of heated water, while too cold water is wasted unproductively.
Not only is this discomfort, but it translates into serious losses over the course of the year. Assuming that the distance between the domestic hot water tank and the draw-off point is 20 meters and the pipes have a diameter of 20 mm, there are approximately 6 liters of water in the pipe. Draining it 3-4 times a day means losing up to 6 to 9 thousand liters of water a year!
Hot water circulation systems are designed to prevent such unnecessary costs. An additional water pipe and a pump enable the circulation of heated water in the hot water system when the taps are closed, so after opening the tap, hot water is immediately available.
This is not the only advantage of circulation pumps. It is also worth mentioning that the movement of hot water in the pipes minimizes the risk of so-called stagnation. These, in turn, promote the growth of bacteria that can deteriorate the taste and smell of drinking water and even cause a serious disease such as legionellosis.
Check out the circulation pumps in the Onninen offer
What should you consider when selecting a circulation pump?
Due to the working environment, the circulation pump must meet a number of strict requirements. First of all, it should be resistant to corrosion and water deposits. To meet this criterion, the material from which the bodies of such pumps are made is primarily brass of a specific composition, as well as bronze or stainless steel. However, the impellers of these pumps are currently made of modern plastics - composites. Contact of these materials with water does not negatively affect its quality. The hygiene certificate confirms that the product is suitable for drinking water installations.
Another criterion for selecting a pump - apart from the materials used and approvals - is its power. Importantly, this value does not have to be particularly high. The purpose of the device is only to overcome the resistance to water flow through the pipes. For this purpose, a lifting height of 1 - 1.5 m is sufficient. Modern, electronically controlled hot water pumps consume only a few watts, older models may be more energy-intensive. You should also pay attention to the efficiency of the circulation pump, which will depend on the amount of water in the installation. It is recommended that the medium be replaced 3 - 5 times per hour, so for use in a single-family house , a pump with a maximum flow of 0.5 m3/h (500 liters per hour) is sufficient.
The design of a modern glandless pump with a spherical motor
The rotor with a permanent magnet has a spherical shape and is supported on a spherical ceramic bearing. It works completely immersed in the water it pumps.
Check out the circulation pumps in the Onninen offer
It is also worth taking a look at the additional functions offered by the pumps, which may affect the comfort of their use, energy efficiency and the efficiency of the circulation system.
Such functions are, for example:
- Automatic pump venting - a special operating mode that helps remove air accumulated around the pump impeller. An air-locked pump works louder than usual, but less efficiently.
- Built-in control clock - allowing you to program the hours at which the pump should work - water circulation is of no use when no one is at home!
- System of automatic adaptation of pumping to the demand for hot water,
- Temperature control – allows you to set the temperature range maintained in the installation so that the water is neither too hot nor too cold.
- Overheating support function - if the installation uses overheating of water to disinfect the installation, the pump should be adapted to this purpose - it can withstand a water temperature of 72 - 95 C for a short period of time. This procedure is used, for example, in hotels and guesthouses.
Hot water circulation pumps
Installation of a hot water circulation pump
The hot water circulation pump should be placed on the hot water circulation pipe - return - directly in front of the heater. This means that the pump supports the return of water from the hydraulic system to the heater. Such an installation reduces the demand for pump power because it only supports the natural movement of water - heated - up, cooled - down.
The position in which the pump is installed can be almost any, but this should be verified in the user manual. The manufacturer usually informs what working position is inadvisable - for example due to excessive load on the rotor bearings or the possibility of condensed water accumulating outside the installation near the electronics or pump connection cables. It is also important to ensure easy access to the pump, especially if it has additional functions that require access to the device to activate. There should be shut-off valves before and after the pump, and a non-return valve is also important to prevent the flow from changing direction when the pump is turned off.
Some pumps are supplied complete with such valves and an insulating cover which, by covering the hot part of the body, reduces heat losses in the circulation. This may be an additional factor deciding on the purchase.
During installation, it is also worth paying attention to the issue of air in the installation. This may occur if the circulation pipe is connected to the hot water pipe above the water supply to the faucet. The air then collects at the highest point of the circulation pipe. To prevent such problems, an automatic float air vent should be installed at the highest point in the circuit.
Exchange benefits in the new OnnTop loyalty platform!
Circulation pumps in the Onninen offer
To ensure the comfort and safety of your hot water system operation for your customers, choose only circulation pumps from proven manufacturers. You will find high-quality devices in the assortment of our online wholesaler. You have the following models at your disposal:
- GRUNDFOS COMFORT 15-14 B PM circulation pump , power consumption 5-7 [W], popular constant speed pump equipped with a 1.5 m cable with a plug and thermal insulation.
- GRUNDFOS COMFORT 15-14 BA PM AUTO-ADAPT circulation pump , power consumption 5-7 [W], with the AUTO-ADAPT system that adapts power to demand. 1.5 m cable with plug and thermal insulation,
- GRUNDFOS COMFORT 15-14 BXDT PM, power consumption 5-7 [W], with built-in time controller, equipped with 1.5 m cable, non-return valve, shut-off valves and thermal insulation sleeve,
- WILO STAR-Z NOVA A circulation pump : power consumption 3-5 [W], with a shut-off ball valve and a non-return valve with a G1" thread
- WILO STAR-Z NOVA T circulation pump : power consumption 5-7 [W], with built-in time controller, temperature control and thermal detection and support function
system for switching on the circuit disinfection function on the boiler side. Complete with thermal insulation, shut-off ball valve and non-return valve. - ONNLINE CP 15-1.5 circulation pump : power consumption 28 [W], basic, constant speed, cheap circulation pump.
- ONNLINE PRO 15-1/65B circulation pump : power consumption 3-9 [W]; with power regulation, automatic venting function, equipped with a non-return valve and thermal insulation.
These are just a few examples of the rich offer of the Onninen installation wholesaler , which includes circulation pumps from respected manufacturers. A wide selection of products will allow you to find a circulation pump perfectly suited to the needs of your customers!
Do you have questions about the industry? Join the Świat Instalacji group!