Building Automation: How Automated Are Our Green Buildings?
The new draft of the “LEED for Healthcare” document is not poised to add any new warmth to our hearts. A close look at this document (or any LEED rating system for that matter) reveals very little direct reference to the use of building automation. In fact, the term “building automation” appears to be used only once in the entire document!
More worrisome is that the USGBC’s recognition of building automation as tool for sustainability is waning. An example is LEED-NC’s credit “EQ 7.2.” In the previous LEED-NC version 2.1, this credit required “… a permanent temperature and humidity monitoring system … .” However, the latest 2.2 version now only requires a comfort survey. So much for encouraging the use of building automation data in optimizing your building!
Bolstering BASPerhaps we should be doing more to help the USGBC recognize how building automation technology makes not only LEED rating systems better, but LEED buildings better. What building automation technology applications should we be suggesting to the USGBC? Here are a few for starters:
Optimize Energy Performance (LEED-NC credit EA 1) – This credit can contribute more points to a building’s LEED certification than any other LEED credit. We think of this as the “DOE-2” credit in honor of the energy simulation computer program that is generally used to achieve these points. However, DOE-2 is known to be fairly inflexible in its ability to simulate many building automation schemes that can increase building energy efficiency. (True, DOE-2 can be supplemented by ASHRAE Standard 90.1’s “Exceptional Calculation Method”, which simply put means any analytical method that can withstand engineering scrutiny can also be used). However, why not enlist the building automation industry to provide some methods or metrics that can more easily predict the energy savings for a variety of building automation techniques not covered by DOE-2?
Outdoor Air Delivery Monitoring (LEED-NC credit EQ 1) – This credit requires the monitoring of both outside airflows and space CO2 levels. BAS are increasingly being used to monitor this information due to the growing popularity of “Demand Controlled Ventilation”. However, why not improve this LEED credit by explicitly requiring that the monitored information also be used to provide demand controlled ventilation? (To be fair, a LEED prerequisite requires compliance with ASHRAE 90.1, which in turn generally requires demand controlled ventilation - but isn’t that a bit too convoluted for a certification program?)
Peak electrical demand reduction (presently not part of any LEED credit) – It is a well-understood fact that peak electrical usage is what drives the need for new power plants. While LEED certification will indirectly reduce a building’s peak electrical demand, this is countered by the much bigger societal trend of retrofitting A/C systems in existing buildings. Therefore, utilities around the country are raising demand charges, developing new rate structures to further discourage peak energy use, and are looking to the building industry to provide buildings that can respond to utility demand peaks. The time has come to work with the USGBC to develop a LEED electrical demand limiting credit.
There are many more building automation applications that could be used to increase the benefits of LEED certification, especially if intelligent building concepts are also considered. Intelligent buildings connect building controls (not just HVAC, but also lighting, security, etc.) with business enterprise systems in ways that can greatly improve building occupant productivity. The USGBC’s mission, which goes beyond sustainability (i.e., resource conservation) to also include occupant productivity, can be greatly bolstered by intelligent building technology.
As an example, an alternative fueling system (LEED-NC credit 4.3) can be activated by an occupant’s security card and, in turn, communicate the metered fuel quantity to the building manager’s tenant billing system. This approach might eliminate the need for a security guard to unlock the fuel system and for building personnel to read the meter and manually enter data into the billing system. The technology and know-how to do this is right at our fingertips – let’s work with the USGBC to make this and other ideas part of the LEED mainstream. ES