Monday, February 3, 2014

The Curious Incident of the Solatube in the Daytime; or The Good, the Bad and the Noisy - Another Reason to Commission Systems and Engage Key Stakeholders

The following is a lessons learned taken from the renovation of elementary school in rural New Mexico. It was part the findings from a post occupancy evaluation (POE) conducted by M.E. GROUP for the New Mexico Public School Facilities Authority. The format it's presented in comes from the Garrison Institute's September 2013 Climate, Buildings and Behavior Symposium.

Intended Goal/Desired Outcome: Remodel existing classrooms in a New Mexico elementary school to successfully bring in large amounts of good quality daylight through Solatubes in order to a) increase the quality of the educational environment and b) reduce the facility’s energy consumption with the further addition of daylight harvesting to those classrooms.


Less than Ideal Actual Outcome: At least one Solatube per classroom ended up having operational issues that were still occurring over a year after occupancy. Damper actuators were constantly opening/closing (independently of the other Solatubes) or becoming stuck in the closed or open position. This created distracting noises as well as constant changes in light levels. In addition to the general distraction resulting from the constantly changing light levels at these Solatubes, when they were located adjacent to smart boards or projection screens, viewing difficulty increased. Add in the general sound distractions and decreased audibility for those students near the malfunctioning Solatubes, the potential negative impact on student learning was significant in those classrooms. 

Low SES (socioeconomic status) students are also disproportionately impacted by facility problems impacting comfort and health, such as these, for a variety of reasons in part related to having on average less support outside of the school. And this school has a large percentage of low SES students, making it doubly important to rectify these issues and in general avoid them to begin with.

The post occupancy evaluation of the school and subsequent analysis led to the manufacturer getting involved again. It was subsequently concluded that the motors in these malfunctioning Solatubes were defective, and new motors were sent out. However, if this does not end up being the fix for all of the Solatubes, other potential causes might involve:

  • Internal electronics damaged from lightning strikes.
  • Low voltage wire runs in excess of manufacturer recommendations.
  • Dimmer fins binding on the tube and stuck (an issue that sometimes occurs during construction). This will over-tax the motor.  
  • Dimmers may need to be reset/synced, requiring coordination with the manufacturer representative.
  • The 0-10V daylight dimmer system was previously discontinued due to lack of satisfaction. If this is what was used on the Solatubes at this school, the circuit boards may need to be replaced with the standard 5V dimmer solution, requiring coordination with the Solatube representative.
  • The custodian thinks that teachers may be inadvertently over-riding and overwriting some of the settings.

What went wrong or appears to have gone wrong? Two things primarily:

  • The lighting control system was not included in the commissioning of the building’s systems, something that should have been considered more during planning/design and worked into the overall budget if possible. This likely would have uncovered at least some of the defective motors prior to occupancy, and possibly some of the other issues as well.
  • The maintenance of the lighting control system fell through the cracks primarily because it ended up being too complicated for the district to work with, and this was not adequately accounted for during planning/design. The integration of the manual wall controls, photocells, occupancy sensors and solar tube controllers is complex and the local electricians have trouble working on the whole system. The school custodian and district O&M personnel didn’t really understand the system that well (including the Solatubes) and neither did the teachers.
    • As a result of the perceived lack of personal environmental control and frustration created among the teachers/staff in the affected spaces, this further negatively impacts their productivity/performance and general teaching effectiveness.

What systematic challenges or issues does this example elucidate? Because of the general lack of local expertise, high tech systems, such as the ground source heat pump (GSHP) system, Solatubes/lighting control system and PV system used at this school typically require importing installation, operational and maintenance expertise from metropolitan areas of the state, increasing the cost and time required to maintain them. As a result, for this particularly rural New Mexico school, they must bring people in from Albuquerque or El Paso to help maintain these systems; at a minimum for small things they often have to get on the phone. It’s frustrating for these smaller, rural districts.

Often such systems in these contexts end up operating below design expectations long term, negatively impacting occupant productivity/performance and health, saving no energy, or worse, using more energy than had the system not been included. At some point they often end up being disabled. This gives high performance, sustainability, green, and/or associated certification systems a bad name – with the teachers/staff and students, as well as the community at large. And they’re less likely to incorporate such elements or similar elements in future projects.

What are the lessons learned? Two basic lessons:

  • Commissioning, commissioning, commissioning: Commissioning, including enhanced commissioning, of all the building’s major systems will typically pay for itself multiple times over. This is certainly the case if productivity and O&M cost impacts are estimated quantitatively and included in any LCCA performed. It is important that the designers and contractors (if involved early on) communicate this clearly to the owner. 
  • Engagement, engagement, engagement: It is imperative that the O&M tasks and costs associated with the operation and maintenance of high tech systems be thought out ahead of time during programming/early design, particularly relative to an owner’s (and community’s) capabilities to determine if the owner lacks the needed expertise and resources. If so, then either a) a path is developed to provide the owner with the necessary expertise and resources through training, systems manuals, a formal building operating plan, maintenance contracts, adequate warranty periods, devoted percentages of operating budgets, etc., or b) alternative design strategies need to be considered that meet owner expertise and resources, save the intended amount of energy and provide high quality environments (learning environments in this case). The school, district and community must be engaged through charrettes, focus groups, surveys, interviews and observations to help determine if a) or b) is the best fit with the district’s and community’s values and goals (short and long term). The process will also likely involve “syncing” the values/goals of these various key stakeholder groups.


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