Guide to Mastering 1-Pipe and 2-Pipe Steam System Balancing to Save Energy and Money
In our continuous effort to enhance building energy, cost efficiency, tenant comfort, and compliance with Local Law 97 carbon emission limits, understanding the nuances of your steam heating system is key. Whether you have a 1-pipe or 2-pipe system, an experienced steam balancing contractor can properly balance and maintain your system for optimal performance and instantly reduce your energy costs by 15-20%.
Identifying Your Steam System
There are structural differences between 1-pipe and 2-pipe steam systems. A 1-pipe system will feature a single pipe through the building in which steam travels up and condensate travels back down to the boiler. A 2-pipe steam system has two individual pipes for each the steam and condensate, thus a 2-pipe system. Radiators in a 1-pipe system will have an air vent on the opposite side of the inlet pipe and radiators in a 2-pipe system will instead have a steam trap opposite the inlet pipe. As a rule of thumb, larger buildings or buildings 7 stories and above will generally have a 2-pipe steam system.
Signs your Steam System is Not Balanced
A properly balanced steam system should quietly distribute steam heat evenly to radiators throughout the building. Common indications that your system is imbalanced are heating complaints from tenants that some apartments are too cold, and some are too hot, banging pipes in the building, and open windows in building during the winter due to overheating, wasting energy and valuable resources. The Entech boiler dashboard is an excellent tool to visually view the wide range of high and low temperatures in an imbalanced building.
1-Pipe Steam Systems: The Art of Venting
For buildings with a 1-pipe steam system, the primary balancing method lies in effective steam main venting in the basement as well as venting the top of the risers. Properly engineered main and riser venting ensures simultaneous steam distribution across the system. However, balancing a 1-pipe system is a delicate process. The installation of Thermostatic Radiator Valves (TRVs) is often considered, but their effectiveness and energy-saving potential hinge on the properly installed main venting. If the venting is not engineered and installed with accuracy, TRVs in a 1-pipe system may not deliver the expected benefits.
2-Pipe Steam Systems: The Longevity of Orifice Plates
In contrast, 2-pipe systems benefit significantly from the installation of orifice plates, offering a sustainable solution to the traditional radiator steam trap repairs. Failed radiator steam traps are the bane of a 2-pipe system and are commonly overlooked due to the difficulty and expense in maintaining them.
Orifice plates, which have experienced a resurgence over the past 10-15 years, represent a method deeply rooted in the original design of steam distribution for radiators, tracing back to the inception of steam heating systems. Before steam traps became commonplace, steam control relied on the strategic sizing of orifices to ensure that only the required amount of steam entered a radiator, effectively maintaining the system’s balance and efficiency.
Key Considerations for Orifice Plate Implementation
Implementing an orifice plate project requires careful planning and expertise. Key advancements in this technology include:
- Evolving Sizing Methodologies
- Steady Pressure Method: This method sizes orifices for a constant steam pressure, typically 2 or 3 psi, requiring strict pressure control. This method has a disadvantage of requiring precisely set controls to always maintain steady steam, which is difficult to accomplish. This has resulted in projects not functioning as expected.
- Max Pressure Method: This method sizes orifices to fill radiators to 80% at the highest expected pressure, offering flexibility and efficiency. Tens of thousands of radiators have been successfully retrofitted in this manner
- Advancements in Steam Flow Analysis
- BES has re-evaluated steam flow rates through orifices using statistical methods as well as engaging a physicist to improve the accuracy of the steam-flow-through-orifice schedule. This enhanced flow schedule eliminates anomalies and ensures adequate heat distribution.
- Introduction of Half-Size Orifice Plates
- BES introduced half-size orifice plates to match the diverse range of radiator sizes more precisely. This innovation ensures uniform radiator fill at maximum temperatures, avoiding significant performance drops.
TRVs in 2-Pipe Systems: Effective Control and Savings
In 2-pipe systems, TRVs are more consistently reliable, providing controlled heating and tangible energy savings. Their role in balancing the system is more straightforward compared to their application in 1-pipe systems. They are typically installed in tandem with orifice plates. It is critical to ensure that your TRV has a stainless steel seat rather than rubber, as rubber tends to wear after a few years.
Energy Savings Through Advanced Orifice Plate Technology
The implementation of orifice plates and thermostatic radiator valves (TRVs) not only optimizes the functionality of steam heating systems but also significantly reduces energy consumption. According to a comprehensive case-study conducted by Con Edison, complemented by our extensive experience, retrofitting a 2-pipe steam system with orifice plates, TRVs, and implementing necessary steam distribution system corrections can lead to an average energy savings of 15%—and in many cases, savings can reach upwards of 20%. Entech’s boiler dashboard can be utilized to monitor for a narrowing of apartment temperature ranges indicating efficient distribution and improved tenant comfort. This reduction is crucial in the context of rising energy costs and increasing environmental regulations, such as NYC’s Local Law 97 (LL97), which mandates reductions in greenhouse gas emissions.
TRVs and orifice plates (or steam trap repair) are two of the thirteen LL 97 affordable pathway energy savings measures that allow low-income buildings to avoid penalties. The deadline for installation is the end of 2024 so if your building might qualify, it is critical to review with an expert to determine if this is a way you can avoid future and increasing LL97 penalties.
Key Considerations for a Successful Orifice Plate Project
Successful implementation of orifice plates requires being prepared to uncover and address pre-existing issues within the steam distribution system. Issues such as broken valves, incorrectly pitched pipes, pump malfunctions, or blockages in the steam or return lines can affect system performance. Initial complaints post-installation, such as tenants complaining about inadequate heat, should be anticipated and welcomed, as they often highlight and help identify underlying issues that need to be addressed to enhance overall efficiency and comfort.
Addressing Common Challenges
Regardless of the type of system, issues such as improper pipe pitching, inadequate piping installation near the boiler, or alterations over time can lead to imbalances, causing problems like banging noises. These issues require professional assessment and correction to achieve a fully balanced and efficient steam system.
Hiring the Right Contractor
It is important to ask the right questions to qualify a prospective contractor and ensure you are hiring a professional.
- How many years have you been installing orifice plates and how many buildings have you worked on? A minimum of 3 years’ experience and about 25 buildings is what is takes to gain competence in this challenging field.
- What is your experience with Master Venting and Riser Venting?
- How will you troubleshoot heating complaints after the orifice plate installation?
You want to hear responses relating to troubleshooting broken valves, incorrectly pitched pipes, pump malfunctions, or blockages in the steam or return lines among other steam distribution issues. A company with a Master Plumber with steam expertise is a major plus.
Requesting references or description of previous projects can also help you choose an experienced steam system balancing professional.
Conclusion
Balancing a steam system, whether 1-pipe or 2-pipe, is a complex task that demands expertise and precision. Building Efficiency Services specializes in diagnosing and rectifying these intricate issues, ensuring your system operates at peak efficiency and comfort. If you’re experiencing challenges with your steam heating system or are interested in exploring potential improvements, feel free to reach out to our team who are ready to provide insights and discuss how these enhancements can be implemented in your building.
This blog was written in collaboration with Building Efficiency Services.
Website: https://bes-efficiency.com/
Email: [email protected]
Phone: (212) 315-3710
