Saturday, October 23, 2010

Quantifying VOC Reductions from Green Cleaning

How do you estimate the reduction in Volatile Organic Compounds (VOCs) from switching to Green Cleaning? To accurately quantify the change, you'd need to know all of the cleaning products used in a building pre- and post-green cleaning, as well as the quantity of each product and the percent VOC content for each. Since I've never been able to get this information (few cleaning companies want to admit to the quantity of toxins they have been exposing their employees and building occupants to), I'm going to try to estimate this based on standards and assumptions found via a very quick search of the web. The numbers definitely won't reflect the exact quantities, but might help give an idea of the scale of the reduction.

For this assessment, let's assume a 100,000 square foot office building. Prices for cleaning very greatly depending on the market and the quality / frequency of cleaning, but let's assume that the cost for this building is $1.00 per square foot per year, or $100,000 per year for this building. According to Von Schrader Company, 1% of this cost typically goes to purchasing chemicals, so we will assume $1,000 is spent on chemicals. According to FAS-TRAK, a typical all purpose cleanier can cost around $10 per gallon, which means that 100 gallons of cleaning product would be used every year in our 100,000 sf building (realistically, this wouldn't all be general purpose cleaner, but for this analysis we'll assume it is). In 2006, the California Air Resources Board issued a report that found the average percent VOC content for general purpose cleaners used in that state in 2003 was 11.63%. This represents 633 grams of VOCs used in the hypothetical 100,000 sf office building using conventional cleaning products. The Colorado Department of Public Health and Environmental, Air Pollution Control Division has a good document that explains how to go from gallons and percent VOC to pounds or product and grams of VOC content.


One of the components of green cleaning is the use of low-VOC products (in addition to micro-fiber mops, HEPA vaccums, concentrated cleaning products with less packaging, etc.). In a green cleaning chemical use matrix I recently saw from ABM, they indicate that their cleaning products have less than 1% VOC content. Assuming the exact same quantity of product as in the conventional cleaning case, this equates to 54 grams of VOCs used to clean the buiding every year.

Based on the analysis and assumptions above, our 100,000 sf office building went from using 633 grams of VOC per year down to 54 grams, or a reduction in VOC of 91%. Having developed green cleaning programs for a number of projects / clients and written contracts and reviewed the programs for many others, I've found that green cleaning is proven to be a no-cost (often cost saving) option that has no corresponding decrese in quality. Besides the many environmental benefits, there is also a significant reduction in toxins. The quick estimate above shows that an office building could reduce an estimated 0.0058 grams of VOC per square foot by making the switch. Many volatile organic compounds are toxins known ot cause eye, nose & throat irriation; headaches, dizziness & nausea; and damage to livers, kidneys & the cenetral nervous system; as well as being suspected carcinogens. Quantifying the health and productivity benefits from switching to green cleaning would require a lot more assumptions (I'd start by seeing what A 1% increase in productivity would be worth), but considering that Americans spend 90% of their day indoors, the switch has to be a good thing.

Sunday, September 19, 2010

LEED Costs

The following is a memo I wrote in response to a question asked by my boss (on behalf of one of the schools).


From: Nathan Gauthier, Assistant Director, Harvard Office for Sustainability
Date: September 9, 2010
Re: Cost of LEED Gold at the Harvard _____ School

There have been a number of studies focused on identifying the cost of sustainability and the cost of LEED Certification. The consensus amongst these studies is that the cost premium varies from project to project, but if there is any premium, it is quickly recovered via the reduced operating costs of the building. Many studies, including a review of historic project costs at Harvard, indicate no statistical evidence of any added costs for LEED Certified projects compared to non-LEED projects. Published papers on the green premium tend to range between 0% and 2%; platinum projects with lots of renewable energy report as high as 15% above standard construction costs. All papers caveat their findings with warnings about the difficulty applying these findings to specific projects. An Office for Sustainability analysis of LEED for New Construction and Major Renovations at the _______ School indicates that all projects of this type can achieve LEED Certification without additional costs and can achieve LEED Gold with the addition of the specific LEED Credits required by the Green Building Standards and agreed upon by the Administrative Deans, the Greenhouse Gas Executive Committee, and the University Construction Management Council. The Harvard required LEED points are generally those that reduce energy consumption and greenhouse gas emissions such as energy efficiency, building commissioning, and energy conservation measure verification. These requirements are pragmatic and provide significant operating savings over time with guidance that only elements that are net present value positive (a simple payback of 12 years or less) be included. Details of these findings can be found below.

Published Studies

The most commonly sited cost studies come from either Davis Langdon or Gregory Kats, both of whom have published multiple studies. The most exhaustive study in terms of sample size is the Cost of Green Revisited by Davis Langdon in 2006, which builds upon an earlier study by them conducted in 2004. The summary of finding is, “The 2006 study shows essentially the same results as 2004: there is no significant difference in average costs for green buildings as compared to non-green buildings.” They go on to identify individual LEED credits that generally have additional costs associated with them such as purchasing green power, installing renewable technologies, specifying certified woods, etc., but note that none of these credits are required to achieve LEED certification.

The most recent whole building cost study is Greening Our Built World by Greg Kats in 2009, which is the culmination of series of green building cost papers dating back to his The Costs and Financial Benefits of Green Buildings from 2003. According to the most recent study, green buildings cost roughly 2% more to build than conventional buildings and provide a wide range of financial, health and social benefits. In addition, green buildings reduce energy use by an average of 33%, resulting in significant cost savings.

The most recent effort to quantify LEED costs was published by Building Green in 2010 and included a number of New England firms on the research team. The Cost of LEED report does not attempt to quantify the overall cost premium of green buildings or LEED Certification, but instead attempts to help estimate the potential cost premium of each of the LEED credits in the LEED 2009 rating system. As such, this paper is not helpful in predicting an overall cost premium unless it is applied credit-by-credit to a planned building. It does point out that the majority of credits can be achieved at little or no cost premium for most projects and that these costs can typically be identified and included in the discussions around Life Cycle Costing and Value Engineering.

OFS Analysis

In 2007, the Harvard Green Campus reviewed the last 50 construction projects at Harvard, and came to the same conclusions as the Davis Langdon reports that there is no statistical evidence of increased hard or soft costs associated with green buildings. Besides having a relatively small sample size, the costs per square foot varied tremendously from project to project even in like building types and the costs seemed to have no correlation to the level of greenness or LEED Certification.

A review of the current LEED New Construction rating system and the Harvard Green Building Standards indicates that all new construction and major renovation projects at the Harvard _______ School can achieve LEED Certification relying only on those credits that have no cost impact such as low emitting materials and construction waste recycling. This review also shows that the addition of enhanced commissioning, measurement and verification, and the 30 to 34% energy efficiency goals bring these projects to LEED Gold while quickly paying for themselves through reduced operating expenses. The Green Building Standards working group used similar analysis to come to consensus around the LEED Gold and specific performance requirements.


Beyond the 3¢ to 5¢ per square foot cost to register and certify a project, it is possible to certify a building at the Harvard _______ School at the LEED Gold level without added construction costs beyond those associated with meeting the agreed upon minimum energy and water performance targets of the Green Building Standards, again which quickly (within 12 years or less) pay back through reduced operating costs. Because of the Green Building Standards’ emphasis on Life Cycle Costing and Integrated Design, the intent is to only include those sustainable design elements that meet the University’s financial payback thresholds and are considered to be Net Present Value positive investments. To this point, LEED Gold certified buildings can be said to be consistently less expensive per square foot on a present value basis than their non-green counterparts. The Harvard _______ School and Harvard Office for Sustainability have a long history of green building leadership and have leveraged this experience to streamline the process and deliver projects that are continually improving over time and being delivered in a more cost effective manner. Clearly defined expectations of the design and construction teams help ensure selection of teams that consider delivery of green buildings to be standard practice and minimal additional fee.

Commissioning Data Center

Last week we walked around the new data center for the management company to perform pre-functional and functional testing (depending on the equipment). The UPS still couldn't be tested because there were still issues with a transfer switch. We looked at the 4 CRAC units, one of which was still hooked up to the vacuum to remove moisture before being re-charged with refrigerant. The two larger CRACs had to have their refrigerant removed, be cut in half to get in the elevator, and then re-assembled. There were a couple of problems with the wiring of one of these, the result of a wiring harness being re-installed improperly. Both of the large units needed to have insulation added since it was removed when it was cut (photo to the right). There was also a very small domestic water copper pipe used for humidification that should be insulated and secured to the frame so that it didn't vibrate against the frame and eventually wear through (photo on the left - the larger diameter pipe was secured with a vibration dapening clamp). One of the large CRAC units was moving 16% less air than it should and the motor was going to be re-shived to fix.

Another of th
e issues we looked for were un-sealed penetrations in the floor and ceiling since both were being used as a plenum for supply (floor) and return (celing) air. The floor was sealed pretty good with only a couple of penetrations that were missed (photo on the left), but the ceiling had lots of unsealed penetrations (photo on the right). Kevin Sheehan (on the ladder) and Kevin Bright (in the floor) are using a flashlight to look for these issues in the photos below.

Another issue we identified during this trip was the chilled water pressure gauges, which were supposed to be 6" diameter and instead were 4" diameter. Obviously this isn't a huge deal, but they were pretty clearly called for in the spec and we've asked the contractor to replace.

Wednesday, April 21, 2010

LEED Certification, When Is It Worth It?

Question from LinkedIn:
LEED per square foot: When is it worth it?

Nathan's Rather Lengthy Response:
We've started to pursue LEED certification for a lot of our smaller commercial interior projects (and all of our big full gut renovations or new construction projects). Once the contractors / designers have worked on a few projects, we've found no soft cost premium (and since we always put the LEED requirement in the RFP, only people who already know or are willing to learn on their dime will respond competitively). For those few firms who say LEED will be a big up charge, we ask why specifically. We will get ridiculous reasons like "to do the ventilation rate calculations", "to track C&D waste diversion", or "to do line of sight geometries." The obvious response is to ask how they were planning on sizing ventilation loads, confirming they were meeting our 95% C&D waste diversion requirement, or verifying the percentage of occupants who could see a window. Since these things are important to us, we have them as requirements in our contracts and construction documents. Since they're important to us, we expect teams to provide verification that they're meeting our requirements. Since they're preparing the verification anyway, there is almost no extra work to go for LEED. Since we are able to collect all of the LEED documentation and compare past projects to future projects, we're able to ensure that our buildings are getting better and better over time (making sure the learning that comes from a project stays with us rather than leaving with the project team). We have seen a tremendous benefit from commissioning but some reluctance on smaller projects, so we now offer an in-house commissioning service for these projects (we've seen amazing benefits even when only commissioning light controls and bathroom fixtures). We don't consider this an added cost of LEED, again because the benefits are so obvious all projects should be doing this, LEED or not. So on a small (say $500,000 classroom fit-out) project, the extra $3,000 seems well worth it to us.

Hard cost premiums are always optional and we evaluate those on a case by case basis in light of benefit to the project versus additional cost (LEED points being only a secondary concern). Added cost for MDF w/o urea formaldehyde? Yes, but the few buildings we've used urea formaldehyde MDF we've gone in, conducted IAQ tests, and can see elevated levels of formaldehyde in the space. Let's go with no urea formaldehyde (our standard). PV on the roof? Payback is generally more than 20 years (as a non-profit we don't get tax credits - this all changes with a PPA). We have other projects we can spend the money on with much better payback / environmental benefit. We typically don't go with PV. FSC wood is case by case. Improved HVAC equipment is usually a yes and we try to minimize additional cost by pursuing utility incentives and using integrated design to right-size everything / realize the interactions between systems.

I completely agree when you're doing most of the work yourself and you’re really passionate you can hold yourself accountable. My brother and I built his house recently and we held ourselves accountable (he did most of the work, but I helped on occasion and with equipment selection). The couple of thousand dollars extra for LEED for Homes was more than he wanted to spend (house cost $350 K). Though the house is beautiful and efficient, as money and time ran short, there are all sorts of minor corners that he or his subs ended up cutting that collecting documentation (which is VERY minimal in LEED for Homes) would have helped address. Admittedly, he's not really passionate about the environment (we was more concerned about utility bills), but imagine what happens as soon as you have somebody else doing your construction with little direct oversight from the owner. Without documentation many environmental claims can't really be trusted and history has proven this over and over again. On a side note, in his market (SW Michigan) he asked the appraiser about the ground source heat pump (what I think is meant by geothermal above) and was told they give no additional value for that system, though a propane tank does add to the home’s value. We went with the GSHP anyway, but only because the cost came in competitive with propane furnace. We didn’t go with the highest efficiency heat pumps because there was no way the system would pay for itself within its life span (we picked a mid-level unit – much of the winter heating is provided by a wood burning stove). How tight was the envelope when we were done? We don’t know because we didn’t do a blower door test. I’m sure he’ll continue to tell people it is tight though because he built it and he meant it to be tight.

Regarding the statement about LEED focusing on design rather than verification, of course this is why there is a LEED for Existing Buildings Operations and Maintenance rating system. All of the same arguments about certification apply. Of course you don’t need LEED to have a high performing building, but to be a good building manager you need to have an energy management strategy and track your utility bills on a monthly basis. You need to have a preventative maintenance plan and keep it up to date. You need to have staff training plans. You need to regularly do energy audits. Etc. If you are doing all of this, then LEED is very easy and has little cost. In all projects I’ve been on (more than 100 LEED projects), the teams that found LEED to be a lot of work were the ones that weren’t actually designing / building / operating in a sustainable manner and creating the documentation seemed hard because it forced them to actually go back and create documents that should have been created from the beginning if they were serious about sustainability.

Just my thoughts, not necessarily shared by Harvard, the USGBC, or anybody else with whom I'm affiliated.

Sunday, April 18, 2010

Why do Building Envelope Commissioning?

A few weeks ago the Boston area received a lot of rain, breaking records for the amount of precipitation in a month. During this time, the third story windows on the east side of our building leaked lots of water. Thankfully, the brick in this area is exposed and un-insulated because the space is semi-conditioned, though the brick on the rest of the building has been sprayed with 4” of Icynene open cell foam insulation and covered with drywall. After the rains, thick layers of scaling appeared on the brick surrounding the third floor window as well as the second floor window. The building, originally built in 1889, had two envelope consultants during the recent renovation. The close up picture shows one of the water drops falling inside of the building. Looks like it could have used some envelope commissioning.

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.

Saturday, March 20, 2010

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.

Thursday, March 18, 2010

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.

Thursday, January 21, 2010

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.

Friday, January 8, 2010

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.