Whole Building Design& Cx IssuesThe “holistic” approach to operating,maintaining & commissioning a facility
Opportunity“Commissioning America” in a decade is an ambitious goal, but achievable and consistent with this country’s aspirations to simultaneously address energy and environmental issues while creating jobs and stimulating sustainable economic activity. (These benefits can only be realized through integrated approach to designing and commissioning buildings)
Our Philosophy• Buildings are made up of numerous components which should create an integrated, efficient and easily maintainable whole. This integration and the attention paid to achieving it is what makes buildings perform as designed.• We believe that it takes a “multi-disciplined” team to achieve this goal. A complete understanding of how all of the components of a building operate as a whole is critical to achieving a building that works.• Our team consists of engineers, architects, test & balance personnel and indoor air quality, building envelope, roof and other component specialists. This allows us to practice strict quality control from the design phase to final occupancy on both new and existing buildings.
Commissioning as Risk Management• Commissioning is more than “just another pretty energy-saving measure.”• It is a risk-management strategy that should be integral to any systematic approach to garnering energy savings or emissions reductions. - Ensures that a building owners get what they pay for when constructing or retrofitting buildings - Provides insurance for policymakers and program managers that their initiatives actually meet targets - Detects and corrects problems that would eventually surface as far more costly maintenance or safety issues.
Green Building Solutions• Whether your goal is LEED, Energy Star, Green Globes or simply having a building which is safe, durable, energy efficient and environmentally responsible, we can help. Our staff includes: – L.E.E.D. Accredited Professionals (NC & EB) – Energy Star Partners – Certified TAB Professionals – Board Certified Indoor Air Quality Professionals – Building Enclosure Specialists – Engineering & Architectural Support
What Is LEED-EB• LEED for Existing Buildings maximizes operational efficiency while minimizing environmental impacts. It provides a recognized, performance-based benchmark for building owners and operators to measure operations, improvements and maintenance on a consistent scale. LEED for Existing Buildings is a road map for delivering economically profitable, environmentally responsible, healthy, productive places to live and work.• Our specialty is measuring and documenting building performance. Our consultants are LEED AP’s with experience in LEED-NC and LEED-EB
Why Commission? Is There a Need?Building problems (a.k.a. “deficiencies”) are pervasive• Design flaws; Construction defects; Malfunctioning equipment; Deferred maintenance• Don’t shoot the messenger: problems a combined result of fragmentation/specialization of trades, “value” engineering, ,increasingly complex building design and operation requirements, lack of clear design-intent documentation and performance targets, etc.• Not attending to problems can cause: – Discomfort --> Eroded productivity, absenteeism – Indoor air quality problems – Premature equipment failure – Litigation – Excessive energy and construction costs
Typical Approach to LEED and Building Cx• Most A/E firms approach LEED program and Cx from an office based perspective• Design, Submittal, O&M Review, electronic submission of info to USGBC• All of this is necessary and a valuable function.• Typically done very efficiently by A/E groups.
Typical Void• A/E groups typically leave field services to other groups – Installing contractors, TAB group, ATC group, CxA.• Lack of field experience with installed systems and most importantly, interaction of building envelope and mechanical systems.• Hidden problems typically STAY hidden until years down the road.
Hidden Problems• Long term problems that arise from seemingly small items that go undetected for many years – envelope air leakage adding unnecessary and unplanned loads to HVAC systems, leading to condensation problems, and eventually mold.• May occur in buildings that have had LEED certification
TAB Problems• Many TAB reports that are false – conflict of interest for TAB specialist to work for mechanical contractor• TAB reports that are accurate, but building envelope has been overlooked.
Potential Problems/Unresolved Issues• Control systems don’t realize their full potential or even design intent.• Building Degradation & HVAC Systems premature failure and underperformance.• Nuisance repairs in year 1 warranty period that typically address symptom and not cause.• Chronic, long term enclosure degradation, moisture problems, litigation, increased maintenance costs.
Save a Little Now, Pay A lot LaterA recent study of anelementary school showedthat if $8,140 had beenspent over 22 years onpreventive maintenance,$1.5 million in repairs couldhave been avoided.-Minnesota Dept. ofEducation
Oversights Cost $$• The cost of oversights during and after construction can add significant costs to the operation & maintenance of the building.• This image shows poor thermal boundary (open to conditioned space) A 2 mph draft was measured in attic coming from conditioned space. This adds to energy inefficiency and also creates building degradation and IAQ issues.
HVAC & The Building Envelope• Fundamental understanding of each of these systems is critical• Knowledge of how they should, can, and do interact with each other.• Knowledge of how to test their performance, individually and interactively.
Skill Sets• Mechanical systems are wide ranging in terms of types and can be very complex.• Designers and contractors typically have areas of specific expertise.• Many projects do not have their project requirements matched with designers and /or contractors who have specific expertise in those skill sets.• This makes field performance testing a good value for owner as it identifies inadequacies early.
HVAC Underperformance• Various national studies by EPA, DOE, ASHRAE, NCI, BPI, LBNL, and USGBC show staggering statistics on building performance.• Residential and Light Commercial HVAC systems perform within 10% of their design intent in less than 1% of American buildings (when including impact of building envelope).• Many operate at below 50% of design intent.• Many installations have not considered indoor air quality.
You Can’t See Air• Airflow problems in buildings are the single largest contributor to HVAC system underperformance.• Often times, even in Cx’d buildings, HVAC systems do not achieve their potential because the building envelope deficiencies go undetected.• Airflows must FIRST be identified. Airflows cannot be successfully controlled until they have been successfully identified. This is a common failure in TAB reports.
Commissioning Scope: Existing Buildings• Develop or update design intent documentation• Plan• Utility analysis, benchmarking• Trend analysis• Building modeling• Findings• Estimate benefits from interventions• Update system documentation (e.g. control sequences)• O&M improvements• Capital improvements (grey zone)• Monitor fixes• Measure impacts• Systems manual/re-commissioning manual
Cx CostsExisting Buildings• Cost: $0.27/ft2 • Median NEBs: $0.18/ft2• Deficiencies: 11 per building• Energy Savings: 15%• Payback: 8.5 months New Construction• Cost: $1.00/ft2 • Median NEBs: $1.24/ft2• Deficiencies: 28 per building• Payback: 4.8 years• Cost-effective over range of energy intensities, bldg types, sizes, locations• Most successful: energy-intensive buildings• Cost-effective outcomes harder in small buildings• Energy savings rise with more thorough commissioning – Source: Lawrence Berkeley National Laboratory
Commissioning Provides Proper Diagnosis Avoid the “Quick Fix” Fixing the symptoms of a building or system problem without determining and addressing the root causes may provide dramatic and immediate savings, but these savings are not likely to persist, and the symptoms may reappear
Benefits of Total Commissioning• Design intent met & • Entities are fully documented accountable for quality• Lower overall operating of their work & maintenance costs • Meet owners project• Reduced liability requirements through• Increased productivity testing & verification
New Construction• Don’t Assume!!• This design allowed roof water to runoff at wall. The lower roof was designed to abut parapet from larger roof. No kick-out flashing was used to direct water away from parapet.• Result – damaged parapet membrane, interior damage, mold, litigation potential.• This could have easily been avoided.
Poor Design• Staining in interstitial space shows stains from moisture running down sheathing and steel stud framing. N ! !!• This exterior wall consisted of brick exterior, 7/8” airspace, ½” DE SIG OR gypsum sheathing, steel stud framing with paper faced fiberglass batts and ½ interior PO gypsum wallboard.
Poor Design• Enclosure design allowed for excessive air leakage, poor thermal performance, no drying capacity.• Result – condensation damage, structural degradation, mold, indoor air quality problems.• A plan review found inadequate capacity of this wall system to dry properly.• This building showed everything building science has found causes problems.
Is There Help for Bad Design? YES…Good Field Oversight
Envelope Commissioning Pays for ItselfA recent study (June 2005) by the US Department ofCommerce and US Department of Energy showedthe energy impact of improving envelope airtightnessin U.S. commercial buildings.It predicted potential annual and cooling energy costsavings ranging between 3% to 36% with the highersavings in the heating dominated climates withpotential gas savings of greater than 40% andelectrical savings of grater than 25%.
Humidity Control Architect and Owner should recognize that the foundation of humidity control is a tight building. Without that foundation, humidity control will be very difficult and costly to achieve, no matter how well- designed the HVAC system might be.Humidity Control Design Guide for Commercial and Institutional Buildings. Harriman, Brundrett, and Kittler. American Society ofHeating, Refrigerating, and Air Conditioning Engineers. ISBN 1-883413-98-2.
The Missing Link?The HVAC designer has a pivotal role in avoiding infiltration ofunconditioned air through the building envelope. Avoiding suchleakage is essential to preventing moisture damage to thebuilding, and essential to maintaining control of humidity inoccupied spacesHumidity Control Design Guide for Commercial and Institutional Buildings. Harriman, Brundrett, and Kittler. American Society of Heating, Refrigerating, and Air Conditioning Engineers. ISBN 1-883413-98-2.
What Is IAQ?• Introduction and distribution of adequate ventilation air• Control of airborne contaminants• Maintenance of acceptable temperature and relative humidityFor IAQ Problems, Four Factors Are Needed…• A source of contaminants• A person(s) affected by this source• A pathway for the transport of the contaminant(s)• A driving source (e.g. air movement) to transport the contaminant from source to hostThe HVAC System Plays a Critical Role in Three of The Four Requirements
How Does IAQ Affect You?Failure to respond promptly and effectively to IAQ problems can have consequences such as:• increasing health problems such as cough, eye irritation, headache, and allergic reactions, and, in some rare cases, resulting in life- threatening conditions (e.g., Legionnaire’s disease, carbon monoxide poisoning)• reducing productivity due to discomfort or increased absenteeism• accelerating deterioration of furnishings and equipment• straining relations between landlords and tenants, employers and employees• creating negative publicity that could put rental properties at a competitive disadvantage• opening potential liability problems (Note: Insurance policies tend to exclude pollution-related claims)
HVAC Design IS AFFECTED by Envelope Leakage Measured leakage rates in 70 commercial buildings (Cummings et al.1996)Cummings, J. B. C. B. Withers,C.B, N. Moyer, P. Fairey, B. McKendry.1996. “Uncontrolled air flow in non-residential buildings.” Final Report of FSEC, FSEC-CR-878-96. Florida Solar Energy Center, Cocoa, Fla.
Poor Design• Roof draining directly into cast stone façade.• Added kick-out flashing to direct water away from the cast stone facing.• This is one of the problems when excessive roof lines are used in design.• Pay attention to the small details!!
Poor Design• Protrusions and gaps. This is not good when it comes to keeping moisture out of your building.• Water loves to enter buildings from ledges where it can sit until it gains access.• The next slide shows the result of such building practices.
Poor Design• Infrared thermography used to locate leakage before opening wall.• The O.S.B. sheathing was found to be saturated, mold covered and structurally damaged as a result of water penetrating from protrusion at window trim.• Costly design.
Understanding The Problems• Why Buildings Leak – Changes-in-plane – Changes in materials – Poor design – Good workmanship based on poor design – Poor workmanship based on good design – Time weighted demise of critical components in the presence of minimal maintenance – Inappropriate material selection – Value engineering (This is becoming all too common in Cleveland Market)
Avoid Waste (Save Our Trees)• Wasted dollars on wasted materials• Thermal bridging issues (condensation)• Convective heat losses• Reduced whole wall R values• This particular job was framed in this manner throughout• This IS NOT GREEN Building technique!!!!
Understand The Problems• Profit over Performance is the precedent.• Poorly trained technicians• Poor oversight on the jobsite• More difficult designs, less qualified installers = poor performing buildings• Using the right materials and trained installers could alleviate many building problems
Air Leakage Is a Priority• Many designers and inspectors pay more attention to vapor diffusion than to air leakage.• Diffusion of moisture is small compared to the amount of moisture carried by air leakage.• Air leakage is one of the costliest deficiencies in buildings.• Results of excessive air leakage are lost energy, building degradation, mold and other iaq issues.
Thermal Bridging Concerns Addressed During Envelope Cx
Moisture Management• “Moisture Damage Contributes to 90% of All Building and Building Material Failures” (ASHRAE)• “Moisture Leading Cause of Building Problems Costing More Than $9 Billion Annually in U.S.” (ASTM)• “Moisture Will Replace Asbestos as the Most Frequently Mentioned Topic in Building Litigation” (C. Gaal, NJ Investigation Commission Counsel) – Source: Oak Ridge National Laboratory (U.S.DOE)
Conception through Occupancy• Moisture issues must be considered from the building conception stage• This consideration must continue through design, construction and O & M phases• Model building conditions and construction at design phase to spot potential problem areas• All flashings, laps, drainage planes, slopes, drip edges must be clearly detailed and dimensioned in drawings• Project oversight is critical during the installation of these critical details (third party is best)
Don’t Rely on Prescriptive Methods• Without third party verification of the performance of the building enclosure there will likely be problems later on• Don’t assume that items complying with the code will properly function in the field• Always assume that mistakes will be made during installations (this is the reason for third party verification)• Finding problems during commissioning is much more cost effective that finding them after building is completed and much cheaper to correct• Pay special attention to the air barrier (this can reduce many moisture and energy related concerns)
Tying It All Together• BAS Systems today can do much more than controlling HVAC systems• Often plagued by problems which lead to under utilization and under performance• Control issues lead the list of systems found deficient during commissioning• A BAS can make commissioning more precise, can also aid in LEED issues
FACP Systems• Fire Alarm Controls may either be tied to BAS or operate independently• Additional layer of controls which require commissioning• Linked to HVAC system operation, damper control, elevator recall, etc.• Problems here can also lead to problems elsewhere
Daylighting & Controls• Lighting control commissioning is critical to energy savings• Lighting control failures are often related to lack of proper commissioning• May or may not be tied to BAS
Motor Alignment• Poor energy performance• Premature wear• Poor life-cycle performance• Excessive maintenance costs
Why Are Buildings Failing?• There are no easy answers to that question. Our experience indicates that some of the more important reasons include: – More difficult systems, less qualified installers – Poor understanding of holistic building functions – Single System approaches to energy, moisture problems, comfort, etc. – Poor understanding of building automation & controls – Lack of Whole Building Commissioning Agents – Limited building science and enclosure specialists – First Cost mentality of many building owners – Not fully grasping potential problems, costs and liabilities