Guest bio
Business Development Manager for Danfoss Heating, Jeff Flannery holds a Bachelor’s degree in Mechanical Engineering from Marquette University and has been in the HVAC industry for more than 25 years. Past positions include Senior Engineer/Project Lead, Senior Project Manager, Senior Product Manager, and Global Product Manager.
Episode summary
What is district energy? What is its potential for buildings, building networks/campuses, and cities in North America looking to improve efficiency, reduce greenhouse gas emissions, lower operating costs, and ensure resiliency? How is today’s technology affecting market development? Tune in to this episode for a conversation on district energy (including heating and cooling) with Jeff Flannery, Danfoss’ business development manager in North America.
Main points
- District energy is a heating or cooling system that covers multiple buildings. An interconnected system of pipes deliver thermal energy.
- Thermal energy is generated in a nearby central plant and distributed to connected buildings by steam, or hot and chilled water. The energy transfer station isolates the district heating system fluids from the buildings’ heating systems and regulates temperatures on both sides of the heat exchanger.
- District energy systems are generally much larger than heating and cooling systems in a single building and are often more energy efficient.
- By combining the heating and cooling loads of multiple buildings, district energy system operators offer energy saving opportunities unavailable to an individual building operators.
- District energy systems started being developed in the 1950s and are more popular in Europe than the US. Euroheat &Power reported in 2017 that District Heating networks supplied about 11–12% of total heat demand in Europe.
- The first district heating systems consisted of centralized power stations which produced steam and was distributed through buried pipe networks.
- Due to high thermal losses in their distributions systems, the later systems moved away from steam and towards progressively lower temperature hot water.
- As water temperatures declined, it became possible to integrate additional sources of thermal energy, such as geothermal or waste heat.
- The current generation of district heating systems are characterized by their ability to integrate multiple heat sources, even heat generated by local grocer’s refrigerated cases.
- The next generation of district heating and cooling system are still in the early stages of development, but these systems will be able to work in heating and cooling modes simultaneously, independent of network temperature.
- Some existing steam-based systems are being converted to hot water systems, reducing heat loss and improving efficiency.
- While it’s common to think about district heating first, district cooling is a fast growing market. In fact, more building square footage worldwide has been connected to district cooling utilities than district heating in recent years, especially in the middle east.
- District cooling operates similarly to district heating, but with chilled water instead of hot. Even the energy transfer stations within the buildings are similar.
- Any building can be to connected to a district energy system, often with dramatic results.
- Developers don’t need to dedicated building space for heating and cooling systems.
- Building owners and occupants save on energy costs.
- Everyone involved lowers their carbon footprint.
- College campuses tend to be ideally designed for district energy systems: they tend to have densely packed buildings and often have greater freedom to make investment and operational changes.
- Most district energy systems use natural gas to operate, but there is a growing trend to integrate other heat sources.
- These include burning biomass, passive solar collection, geo-thermal, co-generation facilities, sewer heat recovery, and surplus industrial process heat (many of which are renewable resources).
- Energy transfer stations use integrated heat exchangers to isolate district heating fluids from energy transfer fluids in the connected buildings. In addition to the primary heat exchanger, they integrate pressure independent control valves, pumps, meters, an array of pressure and temperature sensors, and integrated controllers.
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Links
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More on district heating and cooling in buildings
For more information and additional episodes of the Envisioneering Exchange podcast, visit https://www.danfoss.com/en-us/about-danfoss/insights-for-tomorrow/envisioneering-exchange/