District Heating
What is District Heating?
District heating is a system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating. District heating can offer reduced plant pace, reduced capital cost, and increased energy efficiency. Instead of having lots of little plant spaces for all of the different buildings or apartments, you just have just one plant space in a central location.
The heat is often obtained from a cogeneration plant burning fossil fuels but increasingly biomass, although heat-only boiler stations, geothermal heating and central solar heating are also used. District heating plants can provide higher efficiencies and better pollution control than localized boilers.
Where is the heat produced?
It is ususally produced in a cogeneration plant (Combined heat and power, CHP) or in a heat only boiler station. The CHP generates heat and electricity simultaneously. The combination of CHP and District Heating (DH) is very energy efficient. A normal thermal power station wastes the a lot of energy is form of heat that is dissipated to the environment. The CHP recovers the heat and can reach total energy efficiency beyond 90%.
Other heat sources for district heating systems can be geothermal heat, solar power, surplus heat from industrial processes, and nuclear power.
After generation, the heat is distributed to the customer via a network of insulated pipes. District heating systems consists of feed and return lines. Usually the pipes are installed underground but there are also systems with overground pipes. The common medium used for heat distribution is water, but also steam is used.
Insulated pipes
At customer level the heat network is connected to the central heating of the dwellings by heat exchangers. The water (or the steam) used in the district heating system is not mixed with the water of the central heating system of the dwelling.
| Advantages | Disadvantages |
| More energy efficient than individual heating systems due to simultaneous production of heat and electricity.Less space and volume used on heating in each house. | Long-term investment: high initial capital costs.Not very attactive for areas with low population densities as the investment per household is considerably higher. |
DH in Dundalk.
A biomass boiler provides heating and hot water for the
first major district-heating scheme in Ireland. It serves a
housing development in Dundalk, with heat-exchanger
units from Alfa Laval linking individual dwellings to the system.
The objective is to reduce emissions by 90% compared with
other approaches, increase energy efficiency by 30% and
reduce energy costs by 30%. More info.
DH in Ballymun
Ballymun was the only example of district heating that Ireland
had for many years. Take a look at it Here.
DH in The Eco Village, North Tipperary
The eco-village in Cloghjordan is a unique demonstration of how a new
housing development can achieve high environmental standard.
Involving 132 energy efficient homes heated by a district heating system
using wood and solar energy the project is demonstrating leading edge
technologies and approaches to development. More info here.
