MECHANICAL ELECTRICAL PLUMBING POWER AN ENGINEERING SOLUTION CENTER
HIGH PERFORMANCE BUILDINGS The Definition of Successful Building Design
A Strategic Direction Report Prepared by West Plains Engineering, Inc.
May 2017
westplainsengineering.com
CONTENTS
About the Author
O3 O4 O5 10 11
The Introduction High Performance Building Designation The Issue It’s A Team Effort The Approach Where to Begin to Get to the End The Take Away MEP Impact on Successful Building Design
Works Cited
Michael Heinrich is the Lead Mechanical Engineer in our Rapid City office, and has been with West Plains Engineering since 2000. Michael has special interest and experience in building performance design and evaluation, and holds certifications as both LEED AP and BEMP (Building Energy Management Professional). During his career with WPE, Michael has worked on numerous high performance building designs in the states of South Dakota and Wyoming. michael.heinrich@westplainsengineering.com
2 | westplainsengineering.com
More Than Green Design
The concept of High Performance Buildings is, in essence, the definition of successful building design. More than the “Green Design” movement, this idea places focus on the optimization of every aspect of the building – not just its environmental impact.
The United States General Services Administration (GSA) defines a High
Performance Building as “a building that integrates and optimizes on a life cycle basis all major high performance attributes, including energy conservation, environmental, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality and operational considerations.”Obviously, this widely accepted concept of high performance design is both comprehensive in nature, and quite challenging in practice.
SDSU AME Building The AME (Architecture, Mathematics and Engineering) Building at South Dakota State University is certified LEED Silver and was designed with an HVAC system to meet or exceed ASHRAE 90.1, 62.1 and 55 standards, as well as a lighting system more energy efficient than what is required by ASHRAE 90.1 and LEED criteria.
The following report aims to explain how these attributes correspond to and can be affected by the mechanical and electrical systems of a building’s life, and how variations can lead to increased energy savings. Specifically, this analysis focuses on how engineers first view the building through models and simulations, and then utilize key points within those simulations to mold the building into a high performance design. 3 | westplainsengineering.com
The Issue When it comes to developing high performance buildings, no one area of the team can afford to work in isolation. Architects, engineers, contractors and owners must collaborate on design choices, or risk unknowingly impacting the efficiency of other components of the building. For instance, engineers must look at all elements of the building in relation to one another and how they impact the performance of the mechanical and electrical systems. As will be discussed in the following pages, selecting an appropriate lighting or HVAC design to meet code and owner requirements may be the task at hand. But to achieve high performance design, the engineer must go the next step and determine how decisions such as site location, building orientation, envelope construction and the use of renewables will affect those systems’ ability to perform as expected. While these decisions may seem out of the purview of an engineer’s expertise, it is their responsibility to be knowledgable about the use of each and advise the design team and owner on its impact toward building performance.
Load Calculations and Modeling The good news is that engineers have a wealth of tools at their disposal to accurately predict building performance before the shovels ever hit the ground.
Perhaps most important among these are building energy models and heating and cooling load calculations – which are the “microscope” we use to see how a building will operate. Each has its specific use and reports completely different pieces of information, but when used in partnership, they provide valuable decision-making insight. Energy models provide a snapshot of building energy consumption factoring in numerous end uses simulated over an entire year of operation. Typically, two energy models are constructed, with the first establishing a baseline, which is often a standard building just meeting code compliance. The second model includes the proposed building and its associated components, which are anticipated to be constructed. The comparison between the baseline and the proposed energy end uses can then be used to evaluate the feasibility of a particular energy conservation measure (ECM) upgrade. The heating and cooling load calculations provide the extreme operating conditions for worst case equipment sizing. In other words, the load calculation establishes how much heating and cooling is required during the worst case heating or cooling design day. This information is then tabulated, evaluated for validity and used to select the appropriate HVAC equipment to be installed within a building to keep it operational even under the most extreme circumstances.
4 | westplainsengineering.com
The Approach Location & 1 Building Site Considerations 2 Building Orientation 3 Envelope Construction 4 Renewables
Building Location & Site Considerations
1
The building location on the site can not only showcase the architectural designs, highlight the natural surroundings and connect the building to public transportation – it can also impact the building’s use of energy. The first three items are out of an engineer’s expertise and better left in the hands of the building and landscape architects on the team. However these items should not be ignored by MEP designers, as a building’s use of energy can be affected by adjacent buildings, trees and foliage, which provide permanent shading or function as shelter from strong winds. Though shading and wind breaks cannot be referenced in energy models used for certification, they should be reviewed for building energy optimization and equipment sizing. It should also be noted that these site items can affect renewables (the use of renewables is discussed later in this report). Because of this, great care must be taken to assure the renewable systems are properly located to take optimal advantage of the available energy source, whether it be wind, solar, geothermal, etc. Site energy use can be a large contributing factor to the overall building consumption with the primary contributing factor being site lighting. Several options are available to aid in the reduction of this energy use, including but not limited to, LED Lighting and the use of motion activated lighting. As of this publication, LED site lighting prices are at or near the price of metal halide and HID (High Intensity Discharge) lighting and as such, are typically installed. LED also lends itself to the use of motion activated lighting that HID sources do not. Motion activated lighting is also another consideration for reducing the overall electrical use. The main point of contention by building operators with motion controlled site lighting is the security of the site. Obviously, when lighting is turned off, lighting levels in certain areas of the site are diminished. However, a cleverly-designed motion sensor system can actually enhance security by preventing intruders from recognizing when and where the lighting will be activated. This element of surprise, coupled with the ability to connect the sensor to the overall security system and trigger an alert to the building operator, can make the case for an improvement in the overall safety of the building. In order to allow the owner to make an informed decision – models of the various stages of motion control, compared to lighting levels, along with their anticipated cost savings can be presented. Ultimately, the building owner must evaluate the benefits of energy savings as compared to their security needs.
5 | westplainsengineering.com
The Approach
1 2 Building Orientation 3 Envelope Construction 4 Renewables Building Location & Site Considerations
Building Orientation
2
Due to the fact that east and west facing windows prove to be difficult to use for daylighting, as the sun is either in direct conflict or not present, depending on the time of day, it is best to make every available opportunity to place the majority of building glazing on a north or south facing façade. This allows south facing windows to have permanent reflectors and shades allowing ample amounts of daylighting to occur most of the day without the sun glaring in and a loss of the sunlight benefit due to occupants closing or disabling the shades, negating the benefit of having the glazing. Additionally, photoelectric sensors can be installed with LED fixtures to save additional energy by automatically adjusting lighting levels based on the presence of daylight, while maintaining even light levels for the building occupants.
“
To comply with the ASHRAE 90.1 It’s best to make every available opportunity to Appendix G, Performance Rating Method (“ASHRAE Standard 90.1”, place the majority of building glazing on a north 2016), the baseline building model or south facing façade. must be simulated at a default orientation and then simulated again at the three other cardinal directions (i.e. 0°, 90°, 180° and 270°). The results are then averaged and compared to the proposed case. This provides an Orientation Independent Baseline (normalized) case to compare the proposed building against. Keeping this in mind, evaluating the simulation results from a building rotation may help justify a modification to the orientation of the building slightly to improve the overall performance.
“
Outdoor Campus West This educational facility owned and operated by the South Dakota Game & Fish Department includes floor-to-ceiling glazing on the northeast façade. This allows extensive sunlight throughout most of the day, while architectural shades help control glare as the sun rises in the morning.
6 | westplainsengineering.com
The Approach Location & 1 Building Site Considerations 2 Building Orientation 3 Envelope Construction 4 Renewables
Thermal Bridging An area of the building with higher heat transfer, resulting in an overall reduction in thermal insulation of the total building.
Envelope Construction
3
Though it does not directly use energy, the building envelope is the building and as such, all forms of energy use are tied to it. There are a multitude of techniques on the analysis and implementation of building envelopes, and it is important that the design team is exposed to and educated on these techniques through collaboration with local construction professionals. Before establishing the final envelope construction, it is best to begin with a COMcheck analysis. COMcheck, available for free from the US Department of Energy, is a software tool that checks compliance with energy codes. This is the first check on building compliance with the relevant codes. Since 2004, total building energy savings requirements have increased up to 30 percent, with some building envelope U-Value requirements almost doubling, depending on the climate zone. Another way to improve the building envelope is to evaluate/minimize the places where thermal bridging occurs. Having good insulation is the first step in energy savings, but thermal bridging on a building can erase some of the savings the insulation provides by allowing energy to pass through highly conductive structural materials. A good resource that provides assistance with limiting thermal bridging can be found in the Building Envelope Thermal Bridging Guide (Herschfield, 2016). This guide provides a plethora of building component connections, along with an analysis of bridging connection thermal conductivities. In order to increase efficiency and reduce thermal bridging, a modification to construction norms may be required. As one would expect, when initially introduced, these modifications may give owners pause due to the potential for increased up-front costs. However, as these changes continue to be implemented – their impact on construction costs continue to be reduced, and the long-term return should be communicated to owners. In buildings that seek the most aggressive levels of building envelope performance, designers have to look at how the windows will be utilized, when selecting the performance characteristics of the window. Windows have four (4) main components that affect the energy performance, the Visible Light Transmittance, Shading Coefficient, U-Value and Solar Heat Gain Coefficient. The Shading Coefficient is inversely proportional to the Visible Light Transmittance, i.e. the better the shading coefficient, the lower the visible light that is allowed through the glass. As far as energy is concerned, the lower the solar heat gain coefficient, the less heat gain that will be realized from the solar energy through the glass. Since the solar altitude angle can vary anywhere from 23° to 69° during high noon, dependent on location, the proper orientation, shading coefficient, visible light transmission and correct sun shades/light shelves can make all the difference between good and bad glazing. Approaching a building’s glazing from multiple angles allows each area to be specifically engineered for a particular purpose. 7 | westplainsengineering.com
The Approach Location & 1 Building Site Considerations 2 Building Orientation 3 Envelope Construction 4 Renewables
Envelope Construction (continued)
3
One major consideration is solar energy. Gaining solar energy through a building’s glazing always appears to be a good idea, but the issue can be a lack of control. Particularly in the upper Midwest, temperatures can vary day to day throughout the winter with swings from below zero to well above 30 degrees F. Though the temperature in the spaces may feel comfortable on cold days, the extra solar load in the space during warmer winter temperatures may result in some form of mechanical cooling to keep the space comfortable to the occupants. This is an unforeseen energy use condition, and modeling is the only way to truly determine if the anticipated cooling costs offset the heating energy savings.
Daylighting Glazing
Daylighting Glazing
Light Shelf
Ceiling
Ceiling
Light Shelf
View Glazing
Diffused Daylighting
Shaded Daylighting
View Glazing
Summer Approach
Light Reflective Value (LRV) The total quantity of visible and usable light reflected by a surface in all directions and at all wavelengths when illuminated by a light source. (Sawaya, 2005)
Winter Approach
Daylighting is another good use of glazing, but again the occupant’s comfort must be kept in mind. Daylighting windows should have high visible light transmittance, allowing the maximum amount of daylight to enter the building. However, the windows should be placed and provided with light shelves or other means to reflect the light so as to not cause glare or other detriments to the end user. Interestingly, the color and texture of the reflectors (including ceilings) can quickly affect the amount of daylighting transferred to the rooms, so it’s important to consider colors with high Light Reflectance Values (LRV). “From a sustainability point of view, a wall color with a higher LRV supports lighting plans by helping to propagate daylight deep into the space. Thereby reducing the standard number of lighting fixtures required to enable employees to efficiently and safely perform their tasks.” (Sawaya, 2005) For normally occupied spaces, the lighting levels should be kept consistent to not have adverse psychological effects on the occupants. For this reason, step level control and fast acting changes in lighting should only be used in corridors and other transition areas. Lastly, some of the glazing is just for the occupants to view the outside, i.e., bringing the outside inside. This should be treated as such, meaning the glaring effect of the sun should be considered and limited using automatic shades or overhangs, and solar heat gain coefficients of the glazing should be kept to minimum to reduce cooling load. Automatic control should be used as much as possible to reduce wasted energy, while maximizing the available view.
8 | westplainsengineering.com
The Approach Location & 1 Building Site Considerations 2 Building Orientation 3 Envelope Construction 4 Renewables
Renewables
4
Renewable energy sources have the potential to be a great addition to buildings to reduce their impact on the environment, and to reduce the overall building energy use when properly implemented. Whether it is solar, wind, hydro or another renewable energy source – each has its own particular pros and cons and its application is best determined after careful analysis. Each renewable energy type must be evaluated based on their effective operational data specific to the building locale and the results from an energy model simulation. Though costs are coming down, renewable energy sources still have a large upfront expense. Due to the high cost, renewables should be one of the last items implemented into the building after other less expensive energy conservation measures (ECM’s) have been applied. For the various renewable types, analyzing their performance in a life cycle cost analysis will determine if there is an anticipated payback. In some cases, renewable energy systems may not have a cost payback. If renewable energy options remain a possibility for a high performance building, the designs (structural, site, electrical, mechanical, etc.) should be cognizant of their possible integration. Depending on the type of renewable, they can require significant planning and design to integrate into the building.
Paul Smith Children’s Village & Discovery Lab The Cheyenne Botanic Gardens opened its doors to a new science center and interactive garden for children in 2008. The mission of the Discovery Lab was to teach sustainable living to the next generation by incorporating many different sustainable design strategies, from wind and solar energy to water conservation techniques. Recent calculations have proven these approaches improved energy performance by 35 percent.
One overlooked benefit in projects seeking certification (LEED, Energy Star, etc.) is that renewables can offset process loads; those loads that are outside of heating, cooling and lighting. Beyond the real-life energy savings renewables can provide, they can be incorporated into the energy model to directly reduce these process loads, thus making it easier to meet certification.
Path to Platinum
Day-lighting various spaces Shading devices at south facing glazing in classrooms Optimizing insulation levels in walls and roofs Solar panels to run in-floor radiant heating Natural ventilation Vertical axis wind turbine EnergyStar appliances Waterless urinals/low flow lavatories Fluorescent lighting operated by occupancy sensors, photocell sensors and lighting controls Irrigation system using non-potable water at night, and potable water during the day 9 | westplainsengineering.com
The Take Away Achieving a high performance building goes far beyond well-designed mechanical and electrical systems. Truly reaching the definition and designation for a successful high performance project means going deeper and considering how other features of the structure will both positively and negatively impact operations. The first step will always be to create a baseline model given the known features of a “to code” building. Once that is fully understood, considerations and alterations can be made first to the building location and site; second to building orientation; third to the envelope construction technique and lastly, once all of these areas have been addressed, to the use of renewable resources. The right MEP partner will know how and when to provide guidance on these elements of building design, ultimately affecting the energy conservation, environmental, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality and operational considerations. In like fashion, a failure by the team to address these areas may result in an underperforming building and an unhappy owner.
The West Plains Difference With past experience in five of the seven different U.S. climate zones, all with varying degrees of extreme hot and cold temperatures, West Plains Engineering has a unique view of the built environment and its impact on building energy performance. Through our understanding of load calculations, code compliance analysis and energy simulations – our team is able to assist during all phases of design by providing best practice recommendations regarding High Performance Building construction, operation and anticipated overall energy savings. For more information on our firm’s detailed approach to high performance design, call any of our five regional offices and ask to speak with an office manager. Rapid City: Sioux Falls: Bismarck: Casper: Cedar Rapids:
(605) 348-7455 (605) 362-3753 (701) 751-7322 (307) 234-9484 (319) 365-0030
10 | westplainsengineering.com
Works Cited ASHRAE (2016) Standard 90.1-2016 (I-P Edition) -- Energy Standard for Buildings Except Low-Rise Residential Buildings (ANSI Approved; IES Co-sponsored). Available From http://www.techstreet.com/ashrae/standards/ashrae-90-1-2016-i-p?product_id=1931793 Morrison Herschfield (2016). Building Envelope Thermal Bridging Guide – Analysis, Applications, and Insights. Available from https://www.bchydro.com/construction Sawaya, Lori and Albert R. (2005). LRV Light Reflectance Value of Paint Colors. Available from http://thelandofcolor.com/lrv-light-reflectance-value-of-paint-colors/
11 | westplainsengineering.com
Thank you for downloading our Strategic Direction Report. We hope you found the content relevant, informative and fresh. If you have comments or feedback, please feel free to call us, or email Marketing Director, Kelli Crouse, at kelli.crouse@westplainsengineering.com. If you enjoyed this Strategic Direction Report, visit the website below and sign up to receive email notification each time a new issue is released.
www.westplainsengineering.com/SDR
westplainsengineering.com