ID#5927 made on
EQc7.2 - Thermal comfort - permanent monitoring system
LEED BD+C: New Construction
Thermal Comfort: Permanent Monitoring System Background: Our understanding of this point since the outset of the project design process (initiated under the March 2000 version of the LEED Rating S...
Thermal Comfort: Permanent Monitoring System Background: Our understanding of this point since the outset of the project design process (initiated under the March 2000 version of the LEED Rating System) is that this point requires only monitoring of temperature and humidity configured to provided operators control over thermal comfort performance and effectiveness of humidification and/or dehumidification systems in the building, and does not require a humidification system. We concluded this after establishing that the Thermal Comfort: ASHRAE 55-1992 point required humidification/dehumidification systems to maintain the prescribed performance bandwidths. Further evidence that this temperature and humidity monitoring point did not require both humidification and dehumidification systems was that the monitoring system was to provide operators control over thermal comfort performance and effectiveness of humidification AND/OR dehumidification systems. This conclusion was further supported by documentation requirements (stated in the August 2000 Unformatted Draft Reference Guide) which calls for evidence of the monitoring system components only and a description of building operators interface, but not evidence of a humidification/or dehumidification system. We understand the value of monitoring both temperature and humidity even when (in our case) a humidification system is not provided. In winter, when building RH is prone to go below the ASHRAE 55 minimum, the building operators will know when these conditions exist, as they will be notified by the building automation system by the feedback loop, and can take steps to control RH to a certain extent by modulating temperature, air velocity, and outside air volumes. Humidity monitoring will provide critical feedback for humidity control and performance by the dehumidification system (AC) throughout the entire year as this large project is driven by internal loads requiring dehumidification year round. In the June 2000 issue of the rating system the words "and control system" was added to the documentation requirements for the monitoring point. This prompted a review of the credit interpretations on this issue. One of the credit interpretations for this monitoring point implies that humidification and dehumidification systems, as well as monitoring and control, are required by the monitoring system point. Credit Interpretation Request: Only a temperature and humidity MONITORING system with a feedback loop to the building operator so that they may make adjustments to humidification AND/OR dehumidification system is required by this point, correct?
The intent of this point is to encourage monitoring and control of building temperature and humidity levels. The credit specifically requires monitoring AND control, but the project has some leeway in determining how the control would be accomplished. In general, the project needs to demonstrate that humidity is controlled, or demonstrate through modeling/analysis that humidity control will not be necessary to maintain comfort. It is unclear from the question whether humidity control is proposed or not. To achieve the credit, some level of humidity control is required. To achieve the point, the project could demonstrate that the building sequence of operations addresses humidity control, whether automatically or manually. However, the point would not be achieved simply because the mechanical system has an effect on humidity. (For example, the presence of an air conditioning system alone does not imply that humidity is controlled, merely that the system affects humidity.) As for the need to install humidification and dehumidification equipment, this would be dependent on climatic conditions, as related to attempts to meet the requirements of ASHRAE 55 in EQ credit 7.1 Applicable internationally.
Related Addenda (Corrections & Interpretations)