District cooling Direct and indirect cooling systems
District cooling Direct and indirect cooling systems
The concept of district cooling is In cooling systems the distribution the central system expand or need becoming more and more widespread can be either direct or indirect. If direct, maintenance. all over the world. The idea, as for the cooling water goes directly into the district heating, is to use one central internal piping system of a building. In an indirect system the heat exchanger source instead of local systems for In an indirect system, a heat exchanger will also decrease the static pressure, each building. This will create both separates the internal from the external thus working as a pressure interceptor. economic and environmental benefits. system. Today this is the most Noise from valves can be eliminated common system, and the indirect when the pressure in the pipes is The district-cooling system offers system provides several benefits. decreased. In the indirect system solu- operating flexibility, since each building tion the dimensions of the consumer’s can use as much or as little cooling as Leakage will be easier to detect, and in-home system will be smaller, and needed, without worrying about chiller if it does occur, will create minimum thus cheaper. size or capacity. The installation will be damage. There is no risk of one system very comfortable and convenient for contaminating another. In a district Installing Alfa Laval plate heat exchangers the customer, with the possibility of cooling system the responsibility line in an indirect cooling system ensures using the same supplier for electricity, will be clearer, and the regulation and minimal energy loss throughout the heating and cooling. The installation sales are easier to monitor with clear system. Alfa Laval’s “close approach” of a district cooling system is greatly borders. With separate circuits the enables temperature exchange facilitated if combined with an existing customers may experience fewer approaches of no more than district-heating system, or one built at fluctuations and disturbances, should 0.5°C/<0.9°F. the same time, since the costs can be shared between the two systems.
One of the benefits for the customer is the saving of space at the location as there is no chiller. The investment cost will also be less than when having to invest in a chiller. There will be no need to re-place chiller, cooling towers or pumps due to wear or CFC/HCFC phase-out, as the CFC/HCFC handling problem will be taken care of. With centrally produced comfort cooling there will be no noise or vibrations. Maintenance and running costs will be lower, and a better level of equipment In district cooling one central source is used redundancy and round-the-clock for several buildings. expert management, which individual A district cooling system buildings cannot match, will be has both economic and environmental advan- achieved. tages, especially if combined with district heating in an optimized system.