Understanding LEED IAQ Testing Requirements
Understanding LEED IAQ Testing Requirements
LEED 2009 and LEEDv4 both have credits that require building flush-outs or building air quality testing prior to occupancy. The credit requires that after construction ends, the GC must install new filtration media and flush-out the building by supplying a total air volume of 14,000 cubic feet of outdoor air per square foot of floor area while maintaining an internal temperature of at least 60° F (80° F max.) and relative humidity no higher than 60%. This is a very large volume of air, which leads to flush-out periods that are usually at least two weeks long, often times even longer. There are many nuances that some experts miss while trying to decipher LEED IAQ Testing Requirements.
A 50,000 SF, 2 story office building with 3 fans running at 4000 CFM would have a flush out period running into an astounding 33 days! Moreover, depending on the time of year that construction ends, the temperature and humidity requirements may make the flush-out even harder to achieve, while adding high energy costs. It is also a challenge to find the time for the full flush out duration in the construction schedule.
LEED IAQ Testing or Flush-Out
The other alternative is a phased flush-out. In this case the space may be occupied after flushing with 3500 cubic feet of outdoor air per square foot of floor area. After occupancy, it must be ventilated at a rate of 0.30 CFM per square foot until the total of 14,000 cubic feet if achieved. This too leads to extensive energy use and long flush-out durations, in addition to pushing out the official ‘end of construction’ which may mean financial/ contractual/ logistical implications for the General Contractor.
LEED IAQ Testing Requirements contain a third option of testing the indoor air for contaminant thresholds. While the costs associated with testing are high, this can be accomplished in a much shorter period of time. And if the building passes the first time, the project can come out financially ahead. LEED requirements mandate one test location for each portion of the building served by a separate ventilation system with not less than one test location per 25,000 square feet.
It certainly appears then that the testing option is considerably easier than doing the flush-out. But a lot of project teams hesitate to go down this road partly out of fear of the unknown and partly because they feel that testing is a risky venture with uncertain results. After all, if the project fails, then they will have to do the flush-out anyway, right? True, but the flush-out period for the test option is significantly shorter. If the test for a certain location fails, then the flush-out duration has to be only as long as required to pass the test the next time around, usually about 24 hours. The 14,000 CFM requirement does not apply!
One question that tends to comes up on LEED projects that I would like to address here is that if most products are ‘Low’ or ‘No VOC’ anyway, then why should the building fail the test? Well, it can still happen and let’s examine some of the reasons for it.
First and foremost it’s important to understand the regulatory definition of ‘VOC’. In science we learned that a VOC is an organic chemical with a low boiling point that can evaporate at room temperature. However in the U.S., (unlike the EU & Canada) the Environmental Protection Agency (EPA) considers VOCs as organic compounds that volatilize at room temperate AND react with sunlight to generate smog. So organic compounds that evaporate into the room air but do not cause smog are ‘exempt’ and do not need to be counted. So a product marketed as ‘zero-VOC’ can still have VOCs that are exempt, and are a hazard to human health.
It is for this reason that it’s very important to look for certification labels on products – e.g.: GREENGUARD for a variety of building products, Floorscore for resilient flooring, Green Label Plus for Carpets, etc. These certifications ensure that the products have been tested for total VOCs and other health related attributes, not just smog causing VOCs.
Another common problem is that there are many different primers, aerosols, glues, touch-up kits, cleaning agents etc., that are used during various stages of construction. Many times these products are not submitted for formal review to the Architect or LEED Consultant for prior VOC screening. It comes down to the GC to enforce this with the subs and emphasize the importance of submitting cut-sheets for ALL products that they plan to use as part of their submittal packages.
Finally, it also comes down to the fact that many times absorptive materials like carpet and fabrics can absorb VOCs from other products and release them later.
However there are steps that can be taken to significantly improve the project’s chances of passing the air testing at first shot. For this, I will pass the blog over to my colleague and air-quality testing expert, David Sasse.
Greetings, my name is David Sasse and I am a Certified Indoor Environmentalist with Healthy Building Science, and the one who actually does the LEED IEQ Air Sampling. As such I’m intimately familiar with LEED IAQ Testing Requirements. As a veteran sampler I can give you some information and advice on setting up the ideal conditions for testing and why testing may be the best choice. I will also discuss what to do in the event of a failed sample. Don’t worry! It’s not as scary as it sounds.
There is much that can be done to improve the chances of passing the testing, while staying within the letter and spirit of the LEED IAQ Testing Requirements. I have found that if care is taken when choosing materials, as is the case when attempting LEED certification, the building materials function as designed, with minimal off gassing. Testing is to be done prior to occupancy, but the building should be in occupy-able condition. Thus the building should be empty during testing. This is important as us humans produce many contaminants that could cause the testing to fail.
Here are some recommendations to provide the conditions most conducive to passing the LEED IEQ air sampling.
- All painting, caulking and touch up should be completed at least a week prior to testing.
- The HVAC system should be run on its highest setting (most ACH) 72 hours prior to testing, however during the testing Version 4 requires the air handling system be operated at the minimum outdoor airflow rate for the occupied mode throughout the test.
- Minimum number of people other than the sampling professionals should be present, although if security or safety personnel are required, this takes precedence. Any persons present should be briefed NOT to wear perfume or cologne on the day of sampling. Other personal care products like hair spray and hand sanitizer should be forbidden to be used the day of sampling.
- No cleaning activities should be performed 24 hours prior to sampling, as cleaning products often contain VOC’s.
- Once a sample is set up, no persons should enter the area of sampling for the 4- hour period. Movement can stir up dust and cause particulate samples to fail, as well as VOC’s from the body and clothing can influence the air sample results.
These recommendations are based on prior samplings and the hypothesis as to the reasons for failure. Although a direct correlation cannot be proven, I believe samples have failed in the past because of several reasons:
- Active cleaning crews pushed carts full of cleaning supplies through the sample area.
- Floor buffing was being conducted in an area near the sampling location.
- Touch up painting had occurred the night before sampling.
- Multiple people had walked by the sampling location during the 4-hour sampling period.
All of the above items are preventable and not in conflict with the language in the LEED IAQ Testing Requirements. The sampling is trying to determine if the building is off-gassing any contaminants. Thus the building should be empty, with minimal activity, during the testing. Sometimes it is difficult to create these conditions in a busy, deadline driven construction project. But the above recommendations will create the best conditions to pass the testing. At times we have sampled on a Sunday, when the building could sit empty after work ceased on Friday afternoon, giving the building HVAC time to flush out any built up particles and other contaminants.
Unless there is a major source of contaminants or a sample is compromised by averse actions, I have found that most samples pass. Usually the failed samples only fail by a small margin or for known reasons, as stated above. Often a 48-hour flush out with the building HVAC on maximum is sufficient for the retest to pass.
LEED IAQ Testing Requirements Can Be Beneficial
One of the benefits of the testing over the flush-out is that only the areas that fail need to be retested. I would usually tell a client to budget 15% for retesting, similar to ordering 15% overage on tile and other material. Although if care is taken to give the most ideal conditions, 100% passing on the first sampling is not unheard of.
As Kunjan stated, testing can provide quicker results, can be more cost effective than a full flush out, and gives more positive proof, with tangible lab results, that the Air quality is excellent in your LEED certified new building. Also, given the temperature and humidity requirements of the flush out, maintaining those parameters might be impossible. The testing option does not require additional fans and a long flush out, only the installed HVAC system, the temperature and humidity requirements are within the normal HVAC control range. Usually the sampling can be conducted in one day, with results in 3-5 days (lab results should be expedited to assure any retesting can be performed prior to occupancy).
While testing can be scary, I believe it is a good option and should be seriously considered if you are attempting to obtain the LEED IEQ Credit.
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