Meselson Lab Commissioning

On Friday, we visited the Meselson Lab in the Biological Labs Building at Harvard University as part of the commissioning process. The space's renovation is nearing completion and the Office for Sustainability team was there to functionally test some of the equipment. We verified that the fan coil units (FCUs) and baseboard heating responded according to changes in the thermostat. OFS staff would adjust the thermostats to call for heating or cooling, Talli from Siemens would verify that the the BAS indicated that the system would react accordingly (picture above on the right), and OFS staff would watch the control valves turn and verify the temperature of the coils with a temperature gun (picture below on the right). While the systems reacting appropriately was generally the case, we did find one control valve for the baseboard heating that was unable to open or close because the metal baseboard cover prevented it from turning. This resulted in the perimeter heating being always on regardless of what the thermostat called for or what the FCU was doing. A simple change in control valve location will fix this.

Another potential issue was a discrepancy between the mechanical drawings and the actual HVAC system in one small room. The drawings called for a transfer grille between the small room with an unducted biosafety cabinet and a larger adjacent lab. Since there were insufficient existing wall penetrations, the contractor had used the location of the transfer grille to run the supply air duct. As a result, the room was very positively pressurized with the only path for air to leave being under the door into the hallway. You can see Kevin and Jay from OFS looking over the drawings with Talli from Siemens in the picture below.

We also looked at whether or not the fan coil units reacted to the manual fan speed switches (picture below on the right). Most did, though one seemed to only have an on / off reaction instead of the off / hi / med / low that was called for. We'll come back with a balometer or the testing adjusting balancing (TAB) contractor to confirm. The TAB contractor was supposed to be there on Friday (the reason we selected that date) but he didn't show up, so we'll have to come back to witness test some of the balancing, especially when it is done for the fume hoods. We also confirmed the occupancy sensors (Kevin is covering the sensor with masking tape in the picture below in the center) that control the lighting and the lighting levels at the bench level (Andrea is confirming the light levels in the picture below on the left). This space is not equipped with photo-sensors or dimming ballasts, so we weren't adjusting the light settings, just comparing the actual light levels to the Owner's Project Requirements and Basis of Design.

Solar Assessment at the Krafts

My aunt and uncle are planning to renovate and expand their kitchen and asked me if there is an opportunity for solar photovoltaics as part of the project. The expansion will include a new addition to the southwest corner of the home, which is located in Winchester, Massachussetts. Unfortunately, early in the morning the sun will be blocked from the new single story roof by the existing building, which is three stories above grade. There will also be some time in the spring and fall, when the sun is still lower in the sky, when the neighbor's trees will partially shade the new roof (shown in the picture below without leaves). On average, the area of the new roof will receive sunlight about 66% of the time in the location shown in these images. This perecentage improves a little bit further away from the existing building, but will then be affected more by the trees (and the leaves that will appear shortly).

The analysis was done using a Solar Eye digital camera, which uses a fish eye lens to take a 360 degree photo of the horizon. As long as the camera is set to point towards due south, is leveled before shooting, and has the coordinates of a nearby location (the city of Boston in this case) entered into it's computer, the device is able to overlay the path of the sun and check for times of shading. I'll probably use the PV Watts program to evaluate how much electricity would be produced if they were to put photovoltaic panels on the new roof. We'll also look at the tax credits and rebates available to help offset the initial cost. We'll also try to put a price on the value of creating their own renewable energy on the new roof just below the second floor bathroom used by their four boys and the education they'll receive as a result.

Photos by Lisa Cordner.

Francis Lab Commissioning

On Friday, March 5th, Kevin Bright, Kevin Sheehan, Philip Kreycik, and I met with representatives from the electrician, controls contractor, balancer, and construction manager as part of the commissioning process for the Francis Lab in the Harvard Biolabs building. We checked every occupancy sensor in the space, including those that control the overhead lights and thermostats as well as those that control the task lighting at all of the lab benches. Many of the overhead occupancy sensors were located too close to air diffuser vents and would never shut off, so we had to re-set the sensitivity (in most cases electing to switch them to infrared only rather than using the ultrasonic / infrared dual technology). We also put each fan coil unit into heating and cooling modes and checked schedules and worked with Siemens to fix anything we found such as opportunities for simultaneous heating and cooling or non-responsive thermostats. While there, we compared what was installed to the drawings to see if the as-built drawings needed to be updated. We found a couple of concrete penetrations without sleeves, but determined this was outside the scope of work for this project. We also found a hole in a compressed air line that would need to be repaired. Finally, we checked the face velocity for the fume hoods, making sure that they stayed at 100 fpm at all sash heights. Unfortunately, some peculiarities with the building's HVAC system didn't allow us to run the face velocity any lower. The first fume hood we tested wasn't programmed properly and wasn't responding to the sash height. Kevin Bright continued the functional testing process for the remaining building systems after the rest of the Harvard Office for Sustainability team left and we've since shared our list of issues with the project manager. This is one of multiple visits to the site as construction winds down, which is part of the functional testing component of commissioning. At OFS, we always try to conduct full ASHRAE Guideline 0 commissioning and include plumbing systems in addition to energy systems and include user training in addition to occupant training. We've found the process to be extremely beneficial and cost effective for the interior fit-out projects that we're targeting.

Clark University Presentation

On Tuesday, March 16th, I was a guest lecturer in Professor Will O'Brien's MGMT 252 Green Business Management course at Clark University. The course is supposed to introduce the concept and practice of sustainable development and energy management as they related to local small business, local government, local non-profits, and local citizens. I came in and spoke about how Harvard University was embracing sustainability. My presentation was similar to others I've given on the subject, though updated somewhat. The presentation can be found here.

Professor O'Brien taught a Sustainable Business course as part of the Masters of Science in Facilities Management program I'm pursuing through Massachusetts Maritime Academy. The sustainability plan found here is one my group did for Taza Chocolate as part of that class.

CO2 Sensor Placement

EMAIL: I've been curious for a while about the discrepancy between the recommendations for sampling locations expressed in ASTM D6245 and the ASHRAE and US GBC requirement for being in the breathing zone. After reviewing some of monitoring data for a nearby school, I'm finding that there are significant problems associated with this sampling location requirement, so I thought I'd pass it along.


RESPONSE: Thanks for the paper (indicating temporary CO2 spikes of over 1,000 ppm due to people exhaling near the sensor). I think CO2 sensor placement is like occupancy sensor or thermostat placement in that it must be located intelligently. For an occupancy sensor, it has to sense the people coming in but not be falsely triggered by people in the halls or miss people behind obstacles. For thermostats, they need to be close enough to the occupants to represent their conditions w/o getting direct sunlight to artificially read hot. For CO2 sensors, they need to be in the breathing zone to represent the air that people are actually breathing but not so close to people as to get artificially high readings from nearby exhalation. You always hear about stratification of air and this is why I’d want the CO2 sensor in the breathing zone “strata”. In a well mixed room, I guess it wouldn’t matter, but I don’t know how many rooms are well mixed or how you’d be sure yours was one. I’ve seen a number of engineers place them in a return air duct which is fed from a ceiling mounted grate, but in these same rooms the warm supply air is provided from ceiling diffusers and it seems like fresh warm air could stay along the ceiling and go straight to the exhaust, giving the CO2 sensor an artificial low reading. In the scenario I just described, ASHRAE 62 gives that style of room a 0.8 zone air distribution factor and assumes the room isn’t adequately mixed. In those rooms I’d much rather see it in the breathing zone. We’ve worked on a couple of day cares and talked about demand control ventilation for children and felt the CO2 sensor should be even lower to get the air quality where the kids were actually breathing.

Of course, I’m not the IAQ expert, so I’d defer to you as to the likelihood of adequate room air mixing. Maybe a similar study with CO2 sensors at different elevations would help, though most building owners aren’t going to want to pay for this.

Roof Evaluation for PV

While working with the nice folks at Taza Chocolate in Somerville, MA as part of a class project, I was able to go up on the roof of the 561 Windsor Street building and evaluate it for photovoltaics (note it is sunny because I did this in November and am a bit slow putting the pictures up on the blog). The building has a large flat roof with relatively no mechanical equipment. There are also no tall buildings to the south that might shade the roof. Though it was obvious that the building received direct sun most of the year, I used a Solare Eye camera to verify the path of the sun in relation to the building and determine what times of the year, if any, the roof would be shaded. The picture above (taken with a timer) shows me on the roof, leveling the camera and orienting it due south. Since I’d already entered our location into its computer, it knew our latitude and longitude and could overlay the path of the sun (as seen in the image at the end of this entry).


According to the Solar Eye results, the roof receives direct sunlight 99% of the time sunlight is available. Assuming the 21,761 square foot roof can hold at least 600 SunPower 305 watt panels (shown to the right), which are 62” by 41” each, the PV Watts program from the National Renewable Energy Lab predicts that the roof would produce 210,251 kWh per year in Somerville, Massachusetts. The first cost for this project would be $2,196,000 at an estimated $12 per watt. Assuming a 30% tax credit of $658,000, this brings the project down to a 19 year payback. This payback would be significantly improved when the accelerated depreciation and any potential revenue from renewable energy credits are included. The state of Massachusetts is expected to unveil a new set of renewable energy incentives in January, which will further improve the payback, which would likely be less than ten years when all revenue sources are considered. While Taza does not currently have roof rights to their building, if they are considering a long-term lease they may elect to negotiate access to the roof. Be sure to check out Taza Chocolate if you're in the mood for some great chocolate. Taza is a small bean-to-bar chocolate maker, and the only producer in the US of 100% stone ground, organic chocolate. If you're purchasing in bulk and live within 5 miles or so of the factory, they'll even deliver it with one of their custom tricylces.

Roca Dual Flush Toilets

For the last month I've been traveling in Morocco and Spain. In both countries, I saw a number of dual flush toilets (though still less than half of the toilets I saw). The most common brand seemed to be Roca. All Roca toilets have been dual flush since 2001 and many are 5/3 liters (in addition to the more common 6/4 liters or 1.5/1 gallon). The company is ISO 14001 certified for having an environmental



management system. Haven't seen their products in the US, but they seemed to work well. The picture above is a typical floor mounted tank type toilet from a Tryp Hotel in Madrid, Spain. The one below is a wall mounted tank type with the tank recessed between the wall studs from an Isis Hotel in Essouira, Morocco.