Solar glycol. Why is it used and what should you know about it?

Solar panels are used as an alternative to traditional central heating systems. Thanks to the energy from the sun, you can cheaply and effectively heat a garden pool or even a house. For efficient operation, however, solar panels require regular inspections, including replacement of the heat transport medium. Read how to choose and replace solar glycol .

Glycol in solar panels and the operation of collectors

The task of solar panels is to collect solar radiation (both diffused and reflected). The absorber, which heats the medium in the collector, is responsible for this.

Water can be used as a heat transfer medium, but glycol is much better as it does not freeze at low temperatures and transfers heat much more efficiently.

The heated medium goes to the tank, where it transfers the accumulated heat to the home installation, and then, cooled down, returns to the panels.

What should distinguish solar glycol ?

In order for glycol to work as a heating medium for the installation, it should have the following characteristics:

• the highest possible specific heat and thermal conductivity - thanks to this, the substance heats up quickly and the installation works efficiently;
• low viscosity - a good glycol for solar panels is one that does not cause excessive flow resistance, thanks to which solar panels work efficiently;
• resistance to low and high temperatures - a high-class refrigerant can be used for several years, the loss of functional properties should be very slow;
• anti-corrosion protection - the liquid should not interact with the metal elements of the solar installation in any way. This is influenced by inhibitors that regulate the Ph of the substance.

Solar panels using glycol should also be completely safe for the environment. Therefore, pay attention to whether the fluid is biodegradable. By investing in Renewable Energy Sources, you care not only about reducing expenses, but also about protecting nature.

How often should the solar glycol be replaced?

Individual glycol parameters can be checked using professional equipment - a refractometer or a hydrometer. In turn, the alkaline reserve test takes place in the laboratory and requires access to a laser with the appropriate frequency.

Manufacturers usually recommend replacing the cartridge in the installation after the first year of use. Thereafter, the glycol is renewed once every 5 years or more. You can check the expiration date of the liquid in the technical data sheet.

Each year of using the installation gradually deteriorates the functional properties of glycol, regardless of its validity period. Therefore, the solar installation should be periodically inspected. In this way, you will quickly detect possible leaks and prevent the occurrence of a failure, the repair of which may cost you a lot.

Glycol in solar panels operating at high temperatures will lose its alkaline reserve faster and its anti-corrosion properties will deteriorate. Signs suggesting that it is time to consider replacing the refrigerant may include: a change in the color of the liquid to a brighter one and the appearance of a characteristic smell (you can associate it with the car cabin when the engine overheats).

To the so-called stagnation, i.e. overheating of the installation, occurs when all the heat has not been received. This occurs primarily during hot weather, but it can also be caused by oversizing the installation.

How to replace glycol in solar panels ?

First of all, you must remember that the exchange of glycol should be carried out on a cooled solar installation. Try not to do it during particularly hot days or around noon. Thus, you can get burned by the hot factor.

A good time to replace the glycol in solar panels is early spring or late autumn, when it is still cold outside. Then you don't have to wait very long for the liquid in the installation to cool down.

It is best to use a filling pump to fill the installation with glycol. You can rent it, but a much simpler way is to order a glycol replacement service. You won't pay much for it, and you won't have to wonder if you've done all the steps correctly.

When you decide to replace the glycol yourself, there are a few things to keep in mind.

If your installation has been equipped with pump groups, the valve for filling and draining the medium is located directly on the AHU body. The discharge port of the filling pump should be connected to the bottom valve.

The system is filled from the coil side of the storage heater. This enables effective removal of air bubbles from the metal tubes. Electric pumps are particularly effective.

You should also ensure that the refrigerant level in the overflow tank is appropriate. This will allow the separation of air bubbles from the glycol when venting and filling the system.

Where to buy solar glycol?

The price of solar glycol depends primarily on its technical parameters. Preparations with a higher alkaline reserve will be more expensive. The viscosity of the preparation and the minimum operating temperature also have an impact on the price.

You can buy glycol for solar panels primarily in online chemical wholesalers . When you decide to buy large packages - with a capacity of up to several dozen liters - you can count on attractive prices and discounts as part of loyalty programs for regular customers.

By choosing a specialized wholesaler, you can be sure that you only buy products from reputable manufacturers. They offer products that meet the necessary standards and have quality certificates.

Remember that a well-maintained solar installation works for a long time and effectively. See for yourself that it is worth regularly replacing the glycol in solar panels!