Shasta Middle School

Introduction:

After three weeks of installing a series of 30 Hobos at various locations throughout Shasta, we discovered that the energy usage in this Middle School is excellent and matches with levels in occupancy.

Each hobo produced a graph that looked like this one:

Displaying lighting, temperature, and relative humidity.

Lighting:

All of the rooms in the school had manual light switches that were conscientiously turned off by teachers and faculty at the end of each school day. None of the lights were found to be T12. Possible strategies for saving even more energy through lighting would be to get an automated system, with lights that would turn on only when they sensed movement, low e bulbs, and faders instead of switches.

One of the teachers makes this observation, "If my lights could turn on separately, I would turn on the ones by the wall and leave them off by the windows."

A more dramatic strategy in accordance with this suggestion would be to put in some top lighting; such as light wells that would provide for much more diffuse and evenly distributed light throughout the room .

Relative Humidity (RH):

Here we were looking for any numbers that were below 30% or above 60% that would consequently create an uncomfortable learning environment for students and teachers. But, again all of the RH data collected seemed to be within the normal range, with most ranging around 50%, which is the ideal quantity.

Temperature:

Interview-

To understand the heating system, we interviewed Tommie Glover, the head custodian. The heating system dates back to when the building was first constructed approximately 1967. It consists of two large boilers of water that are heated by gas up to 250 ° F and then pumped to each classroom, which has its own thermostat, and lets in a correlating amount of water. The heat thus radiates down from pipes that run through the ceiling.

Surveys-

We handed out surveys to all of the teachers to determine their level of thermal comfort. A common complaint observed as this teacher states is that it is too cold Monday morning when the heat kicks back on,

"The heat is turned off over the weekend so when I get here at 7:30am on Monday, my room is freezing. Last Monday, it was 55°, and I had an IEP meeting. It usually warms up by 9am and stays warm the rest of the week."

Through further investigation, we found that the heater needs to be turned on 2 hours prior to the arrival of the teachers on Monday morning to be able to reach at a level of thermal comfort for when they get there. This would not serve as a form of reducing energy loads, but is important to the comfort and well being of the teachers.

Click here to see a copy of one of our Teacher Survey's.

It is interesting to note that a lot of the opinions teachers had about the temperatures of the rooms being too hot or too cold, did not match with the actual temperatures of the rooms.

Hobos-

There were 20 out of the 27 rooms that got to be too hot for more than one day out of the week that was studied, but the temperatures never got above 81 ° and they only lasted for an hour or less. A simple adjustment of the thermostat to a lower temperature would fix this problem.

Overall, most of the classrooms maintained temperatures throughout the week that were between 65-71 ° F, which ASHRAE defines as being thermally comfortable.

In terms of matching occupancy, the shut-off time for the heating system is perfect, right around 4:00pm. This is an hour after classes let out and gives teachers enough time to put their stuff away and wrap up before it gets too cold in their classroom.

There were nine rooms that maintained temperatures within the range of thermal comfort over the weekend when the system was off! Therefore, there is the possibility of experimenting with turning the heat off or down during the week in these classrooms to save energy.

Other suggestions to promote energy efficiency are to group some of the classrooms together on a grid that would control the heating, installing some thermal mass walls (i.e. water jugs in the window) that would reradiate passive solar heat gained from the sun, or even installing some solar panels on top of the school to collect energy.

Conclusion:

To conclude, the energy use at Shasta seems to be more than appropriate and consistent with occupancy. In June, we will gain more insight by being able to compare Shasta's energy usage with the two other schools being studied. We will also be running Shasta through Portfolio Manager to discover its energy usage that way.