Waste water utilisation

Heat is always generated during cooling processes

In all cooling processes, heat is generated. This heat can either be waste if not utilized or it can be used to heat another space. An illustrative example from everyday life is a refrigerator that keeps its interior cold while releasing heat into the surroundings. Because a refrigerator is a small device, the emitted heat is negligible and not felt in the room. However, in industrial and larger facilities where cooling needs due to processing and manufacturing are substantial, envisioning them as enormous refrigerators results in significant amounts of waste heat being released into the surroundings.

A valuable heat source that is already here and we don’t need to acquire it

If the impact of heat emitted into the surroundings from a refrigerator is negligible, it’s not the same for large industrial facilities, where waste heat needs to be expelled from the building using fans and cooling systems, either into the air, rivers, lakes, or the sea. Processes that require intensive cooling include cooling wine cellars, cooling lasers for cutting, laundries, ventilation of mine shafts, food processing, and more.

Waste heat is low-temperature heat that cannot be directly utilized. It can be seen as untapped energy, a valuable heat source already present that doesn’t need to be acquired — we just need to know how to harness it.

Waste heat that is not waste

This heat can be viewed either as a burden, representing waste, or as a great asset that can be used to our advantage. At KRONOTERM, we chose the latter option years ago, offering systems that harness waste heat to make it usable for other processes. Among the typical processes for which we can utilize waste heat are heating buildings and heating sanitary water.

How can we use waste heat?

Utilizing waste heat is possible through air using an air/water heat pump or through water with a water/water heat pump. Let’s look at a specific example: Many industrial facilities often discharge wastewater at a temperature of 30°C into the environment, such as into the air or surrounding water bodies (streams, rivers, etc.). Water at such a temperature represents an extremely favorable heat source, which we at KRONOTERM know how to harness with the help of a heat pump. Water at 30°C is not inherently usable, but with a KRONOTERM heat pump, it can be heated to 50°C, and with a heat pump with boosters, it can reach over 80°C. This heated water can then be used for heating buildings, heating sanitary water, and incorporated into district heating systems.

Waste heat: the gold we throw out of the window?

How favorable a heat source is with an initial temperature, say 30°C or higher, can be illustrated by comparing it to other heat sources utilized by heat pumps. Typically, water/water heat pumps efficiently utilize a heat source such as groundwater with a more or less constant temperature throughout the year, ranging between 8 and 12°C. On the other hand, air/water heat pumps extract heat from the air, which in winter can have a lower temperature, potentially even lower than -10°C.

When both types of heat pumps need to extract heat from sources with these mentioned temperatures and prepare useful heat for heating spaces or warm sanitary water at 60°C, it means that heat pumps, especially air/water ones, have a more challenging task when utilizing waste heat at 30°C. The difference between the temperature of the heat source and the desired temperature of useful heat is considerably higher—raising the temperature from 30°C to 60°C requires less input energy. Therefore, based on this, returning to the utilization of waste heat: waste heat at, for instance, 30°C is simply too good of a heat source to just discard.

Waste heat: the gold we throw out of the window?

Positive environmental impacts

Utilizing waste water not only significantly reduces building operating costs due to saving primary energy but also has a substantial impact on the environment, reducing greenhouse gas emissions. KRONOTERM, with this technology, has successfully contributed to reducing environmental pollution and costs even in the company where the largest heat pump in Slovenia is installed—the KRONOTERM heat pump.

When waste heat is not a burden,
but an asset

CHECK OUT THE STORIES OF OUR SATISFIED USERS

ACHIEVING MAXIMUM UTILIZATION OF GEOTHERMAL ENERGY WITH HIGH-EFFICIENCY HEAT PUMPS

SLOVENIAN LARGEST HEAT PUMP

When waste heat is not a burden, but an asset

CHECK OUT THE STORIES OF OUR SATISFIED USERS

ACHIEVING MAXIMUM UTILIZATION OF GEOTHERMAL ENERGY WITH HIGH-EFFICIENCY HEAT PUMPS

SLOVENIAN LARGEST HEAT PUMP

When waste heat is not a burden,
but an asset