Intelligent Control of Window Shading and the Energy Triangle
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Automating window shading systems in commercial buildings can significantly reduce energy consumption from lighting, heating, and cooling, which typically represent up to 65% of total energy usage. Automated shading optimizes natural light use, enhances visual comfort, and can lower energy costs, while also meeting various regulatory energy efficiency standards. The integration of intelligent controls, such as timers and sun sensors, facilitates energy management and comfort while supporting sustainability initiatives.
Intelligent Control of Window Shading and the Energy Triangle
- 1. Justin Fransila Intelligent Control of Window Shading And The “Energy Triangle” 1
- 2. Why Should a Building Owner “Automate” a Shading System? In a typical commercial building, lighting, heating and cooling represents as much as 65% of the total energy consumption, which puts a significant burden on an operating budget. Reducing the cost of such energy loads, can easily be achieved by “ automating” window shading systems, whether interior or exterior. Since “ manually” operated shading systems are used less often, employing an automated system can be more effective in managing solar gain and glare, which in turn, enhances one’ s ability to utilize existing natural light as a substitute for artificial (electric) light, the end result being, “ a reduction in energy costs” . * Source: www.esourcecompaniesllc.com 2
- 3. Intelligent Control of Window Shading The Energy Triangle Natural Light Control Somfy “Energy Triangle” HVAC Systems Artificial Light Control 3
- 4. The Energy Triangle “Bridging the Elements” Artificial Lighting Heating and Cooling Natural Light Control 4
- 5. Shading 101 What is the purpose of a window shade? Fundamentally, the purpose is to “mitigate solar gain and provide comfort from glare” Factors that dictate what type of window shade is used include: Cost, aesthetics, functionality and type of application Ultimately, when one considers the various factors, a solar screen roller shade can be considered the most viable shading choice for most commercial applications 5
- 6. Shading 101 Why is automated window shading important? The fact is, the vast majority of “manual operated” shades, do not get moved, often remaining in the closed position, thus not providing one with the benefits of natural light, or conversely, in the open position, thus increasing the need for air conditioning the space. The type of window shade is also important! Vertical Blinds are often used in commercial buildings, mostly due to cost. They are rarely automated and have proven to be the least effective method for natural light control, providing no ancillary benefits in terms of “ daylighting” or “ load shedding” . 6
- 7. Motorization is available for all types of openings and closures of homes and buildings. RESIDENTIAL Energy savings Comfort Security COMMERCIAL BUILDINGS Energy savings Natural ventilation and visual comfort 7
- 8. Intelligent Control of Window Shading Energy saving benefits are increased because motorized window coverings can be: Programmed to operate at certain times of the day Programmed to operate depending on the amount of sunlight Programmed to operate based on the amount of sunlight and temperature Controlled remotely via a central control or the internet 8
- 9. Intelligent Control of Window Shading Optimize Natural Light “Sun Tracking feature” Shading device controls can offer a Sun Tracking feature that positions the hem bar on a sun screen or the blades on blinds or louvers according to the direction of the sun's rays Sunlight is free and by reducing the use of artificial lighting allows energy savings. Artificial lighting can amount to 35% of a commercial building's energy costs ! 9
- 10. Intelligent Control of Window Shading Optimize Natural Light •Automated shading devices with timers and sensors optimize natural light inside the building and can still be controlled individually •Maximize use of natural daylight to ensure greater visual comfort, reduce the need for artificial lighting, lowering energy consumption and operating costs. •More comfortable to the human eye, sunlight has proven itself as the best source of well-being. •Studies show benefits in schools where grades have improved, •and in offices with higher productivity and lower absenteeism rates. 10
- 11. Intelligent Control of Window Shading What is the relationship between Natural Lighting and Artificial Lighting? Simply “The use of natural light to supplement artificial light” aka “Daylighting” or “Daylight Harvesting” 11
- 12. Intelligent Control of Window Shading Window Orientation Summer •Direction that windows face for cooling and heating •Southern Windows High exposure to sunshine Excessive heat loads for cooling •Northern Windows Small amount of direct sunshine Excellent for Cooling Illuminations •Eastern / Western Windows Susceptible to heat radiation Long exposure to sunlight in each direction 12
- 13. Intelligent Control of Window Shading Fabrics and How They Effect Energy Management Items that effect energy management Color Dark - Good for heat absorption, poor reflective properties Light - Heat dispersion into room, better for heat reflection Opaque - Room darkening, excellent for heat absorption Weave Density Will determine how much heat is absorbed and or dispersed within room Material Heavy weight fabrics - Heat collection, poor light dispersion Light weight fabrics - Heat and light passes through easily 13
- 14. Intelligent Control of Window Shading Types of Shading •Roller Shades •Provide diffused light and keep heat between window and shade in turn keep heat out of room. Allows for external viewing. •Southern exposures between 8:00am and 4:00pm with white opaque shades reduce heat gain by 64%, white translucent shades can reduce heat gain by 56%, and dark shades can reduce heat gain by 30%. •Western exposures between 12:00noon and 6:00pm with white opaque shades reduce heat gain by 68%, white translucent shades can reduce heat gain by 60%, and dark shades can reduce heat gain by 33%. •R-value of 2.0 to 4.0 can be achieved with roller shades •Blinds •Use of blinds on a sunny window can reduce heat gain by 45% if blinds have a reflective coating, fully lowered, and completely closed •Draperies •Can cause the chimney effect by letting heat into the room but are effective in keep cold out 14
- 15. Intelligent Control of Window Shading Digital Network Motorization A bold new approach to the automation of window shading systems, providing unlimited functionality without “complexity & excessive cost”. Similar in concept to an “ethernet network”. Follows principle of “distributed intelligence”. Smart Controls driving an “intelligent motor”. •Built in microprocessor •Individually addressed •Two-way communication •Multiple intermediate positions •Unlimited grouping possibilities 15
- 16. Intelligent Control of Window Shading A cost-effective solution for “Energy Management”. •Unlimited control via in-wall or virtual switches. In-wall switches need only be connected to the bus line. Virtual switches can be loaded on any web based device. •Remote access to shades via internet connection. Provides for easier maintenance and monitoring of shade systems, such as via an IPAD, which might be carried around by Maintenance Personnel. In-wall Virtual hard Type wired Switches switch 16
- 17. Intelligent Control of Window Shading “Virtual Switches” – actual examples of “Graphical User Interfaces” As seen on a PC or laptop As seen on an IPAD or Smart Phone 17
- 18. Intelligent Control of Window Shading Digital Network Motorization •Simple to Design System is totally “scalable” – pre-planning is not as necessary. Options for control can be easily applied “after the fact”. Control can be personalized, according to the client’s needs. •Simple to Install Utilizes standard “off the shelf” wiring for power and data. •Conventional 12/2 or 14/2 for power – CAT5 for data. Motors can be plugged in to standard duplex outlets. No need for “Home Runs” and “Motor Controllers”. •Simple to Program Software based controls are easy to configure and adjust. •Simple to Operate Intuitive switches in both “in-wall” and “PC based” versions. Easy to apply “time schedules” for “daylighting” purposes. Integrated control via any 3rd party option, including, “home automation systems” “touch screens” “smart phones” “building management systems 18
- 19. Intelligent Control of Window Shading “Time Scheduling” and/or “Sun Tracking” •Minimal componentry •Minimal programming - Maximum Energy Savings •Minimal maintenance Time Scheduling • Utilizes time based set points, to move shade (s), with or without sun sensing. • Simple to program and often effective, when applied to smaller building envelopes. Sun Tracking • Utilizes sun activated set points, in increments as small as one degree, depending on the need. Set points are determined by algorithms built into the software that are based on the latitude and longitude of a given locale. • The complexity of the programming and the number of photocells (sun sensing) required, is contingent on the size and character of the building envelope and the level of accuracy demanded. Though the fundamental purpose of sun tracking is to increase energy savings by maximizing the use of natural light to supplement artificial light (daylighting), that is, if dimming ballasts are employed, this can even be accomplished through the use of time scheduling, albeit less accurately. The result may not be as productive in terms of energy savings, but nevertheless, significant, with a payback or “ROI” which is faster, due to a lower “up front” cost. 19
- 20. Intelligent Control of Window Shading Sun Sensors “Wired and Wireless Options” Operates motorized window coverings in accordance to the amount of sunlight received. Sunlight sensitivity (threshold) can be adjusted for varying degrees of sunlight intensity. Sun Sensors reduce heat gain while providing UV protection. Reduces heat gain while providing UV protection. Simple wireless option for raising and lowering shades and “programmable” wired options for “sun tracking” purposes. Can be employed as a stand alone “ energy management” tool, such as in applications where shades simply need to go “ up” or “ down” based on sun conditions, or as an integrated “ energy management” tool, when used in conjunction with “ time scheduling” or “ sun tracking” 20
- 21. Intelligent Control of Window Shading Digital Network Motorization How does it “ impact” project considerations? •Budget System must respect the overall cost of the project. • Advanced technologies allow one to reduce system costs. •Functionality System must meet the needs of the end user. • Advanced technologies allow one to more easily accommodate needs. •Maintenance System must be easy to operate, adjust and repair. • Advanced technologies provide a more user friendly and accessible system. •Adaptability System must allow for changing client requirements. • Advanced technologies provide a more flexible system which is scalable. 21
- 22. Intelligent Control of Window Shading Automated Shading and How it Applies to Regulatory Bodies Though Solar Screens and Shading Systems in general, are not directly recognized as an energy saving devices, various State and Federal initiatives are demanding that stakeholders take steps to lower solar gain and reduce energy costs. LEED does recognize the value of a window shading system, from the point of view of “optimizing energy savings” and providing “thermal comfort”. Many governments and utilities have adopted LEED as the basis for their incentive programs, but they vary from state to state, let alone community to community. Nevertheless, the USGBC concept is now accepted as a “de-facto” standard for “sustainable design”, within the architectural community. California “ Title 24” , does specifically state that, “ one will take steps to lower their solar gain, or they will be penalized” . California Title 24 “ 2013 Building Efficiency Standards indicate a specific goal that new building standards achieve "net zero energy" levels by 2020 for residences and by 2030 for commercial buildings. The Federal “ Tax Incentives Assistance Project” provides tax deductions to commercial building owners that save 50% or more of “ projected annual energy costs” for heating, cooling and lighting. The employment of automated shading systems, can be an effective catalyst in achieving the “load shedding” goals, when used in consort with occupancy sensors and dimming systems, especially in terms of “unoccupied spaces”. 22
- 23. Intelligent Control of Window Shading Remember the “ Equation” Automated Shading = Energy Savings Thank you 23