District heating

Modern district heating (DH) is actually more than 100 years old. Modern DH started around the turn of the 20th century n Moscow, Frederiksberg, and Copenhagen. It’s used in European nations, Russia, and China to a more significant degree today than in the rest of the world, however, district heating has risen in popularity and use throughout much of the rest of the world.

District heating is also known as "district energy", as there are district systems that can provide both heating and cooling. Using district cooling, like district heating, is more cost-efficient and fuel-efficient than traditional heating, ventilation, and air-conditioning (HVAC).

District energy has proven its effectiveness in improving energy efficiency for buildings primarily throughout Europe and Asia, although these systems are gaining ground in the rest of the world, as well. Here is a chart that illustrates where district heating and cooling is found, and information on what sector it's used for-

In this article, the focus is on district heating, which like district cooling, is more efficient than conventional HVAC. Please note that:

"The cold deliveries from district cooling systems are much smaller than heat deliveries from district heating systems." [quote from - sciencedirect.com]

DH is generally implemented when a municipality makes use of otherwise wasted heat. DH uses excess heat from a power plant to create heat for buildings or homes in a city by sending the heat (usually in the form of heated water, steam, or gas) through insulated pipes to homes and buildings to be used as space or water heating.

Heat and energy for district heating are often derived from the use of excess heat from energy generation in combined heat and power (CHP) plants. District heating systems using cutting-edge technologies were designed and introduced in the 1980s (with constant breakthroughs since then)-- with automatic control, remote monitoring, and unmanned operations.

Please also see:

Combined Heat and Power (Cogeneration) - Making the Most Out of Energy

District heating explained

A typical district heating installation consists of a highly insulated "heat main" of flow and return pipes past all buildings (housing, commercial, business, and municipal buildings) which are connected. A junction point allows easy connection to each building, from which hot water, steam, or gas, can be taken from the main to a heat exchanger within each building.

The heating circuit within the building is thus isolated from the heat main. Temperature measurements of the flow and return lines, plus a flow meter (together forming a heat meter), allow the actual heat usage within each building, or even each apartment, to be separately measured, delivered, and billed accordingly. Remote meter readings, by a modern, secure web interface, or a drive-by, are both usually possible. Most DH systems today use remote diagnostics to ensure reliable operation.