Overview
ISO 11855-4:2021/Amd 1:2023 is an international standard published by ISO that focuses on the dimensioning and calculation of dynamic heating and cooling capacity for Thermo Active Building Systems (TABS). As a key part of the ISO 11855 series, this amendment updates the methodology for designing embedded radiant heating and cooling systems, specifically Type V TABS. These systems integrate heating and cooling elements directly into building structures to achieve enhanced thermal comfort and energy efficiency.
This amendment emphasizes dynamic calculation methods that consider variable heat gains such as solar, internal gains, and ventilation loads, allowing for accurate sizing of cooling systems - including chillers and hydraulic fluid circuits. The standard supports sustainable building environment design by promoting the use of renewable energy and reducing overall energy consumption within buildings.
Key Topics
- Dynamic heating and cooling capacity: Methods to calculate peak and continuous thermal loads for TABS to meet occupant comfort and energy efficiency requirements.
- Thermo Active Building Systems (TABS) Type V: Specific guidance on dimensioning embedded radiant systems integrating pipes or electric cables within structural layers.
- Heat gains consideration: Incorporation of solar gains, internal heat sources, and ventilation air for realistic capacity calculations.
- Hydraulic and thermal system design: Calculations supporting the correct sizing of water-side cooling equipment and flow rates.
- Thermal comfort criteria: Maintaining occupant comfort based on ISO 11855-1 guidelines and including predicted mean vote (PMV) as a performance indicator.
- Energy saving focus: Strategies that leverage dynamic simulation to reduce energy consumption and heat source sizes.
- Equivalent thermal resistances: Tools for modeling heat transfer resistances between construction layers to aid in building simulation.
Applications
The ISO 11855-4:2021/Amd 1:2023 amendment is practically valuable in several key areas within the building and construction industries:
- Architectural and HVAC design: Professionals can use these calculation methods to design embedded radiant heating and cooling systems that integrate seamlessly into building slabs and core layers.
- Energy-efficient building projects: Designers aiming to implement renewable energy-based climate control can optimize TABS to reduce reliance on conventional heating and cooling systems.
- Simulation of building thermal performance: Enables dynamic computer simulations for evaluating building energy demands and system control strategies.
- Sizing of mechanical equipment: Accurately determines the chiller capacity and fluid flow requirements needed to service TABS, improving system reliability and operational cost savings.
- Compliance and certification: Helps meet standards compliance and support green building certifications by adhering to recognized thermal comfort and heating/cooling capacities guidelines.
Related Standards
ISO 11855-4:2021/Amd 1:2023 works alongside other parts of the ISO 11855 series to provide a comprehensive framework for embedded radiant systems:
- ISO 11855-1: Specifies comfort criteria for embedded radiant heating and cooling for occupant thermal comfort.
- ISO 11855-2: Offers steady-state calculation methods for heating and cooling capacity.
- ISO 11855-3: Details design and dimensioning methods to meet thermal capacity needs.
- ISO 11855-5: Addresses proper installation procedures of embedded radiant systems.
- ISO 11855-6: Provides control methodologies to ensure optimum system performance during operation.
- ISO 11855-7: Contains calculation methods relevant for input parameters used in ISO 52031 for building energy modeling.
Together, these standards support the development, design, installation, and operation of embedded radiant heating and cooling systems worldwide.
Keywords: ISO 11855-4, Thermo Active Building Systems, embedded radiant heating and cooling, dynamic heating capacity, cooling capacity calculation, building environment design, energy-efficient HVAC, radiant cooling system, thermal comfort standards, renewable energy buildings, building simulation, chiller sizing.