Sustainable Energy Use

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This page is maintained by the Sustainability Committee at the American Institute for Conservation of Historic and Artistic Works (AIC). It is intended to provide information about sustainable practices for AIC members, conservation/preservation professionals, and other interested parties within the cultural heritage profession. Please send comments and suggestions to sustainability(at)conservation-us.org.

Thinking about Sustainability and Energy Use

The current model for energy consumption assumes that there will be an infinite supply of resources that we now know are finite like fossil fuels like oil, coal, and uranium for nuclear energy. The realization that there is a finite amount of material in the world to make energy has encouraged energy conservation. Energy conservation is an effort made to reduce energy consumption and can be be achieved through more efficient energy use, decreased energy consumption, and reduced consumption from conventional energy sources.

Many practices to reduce energy consumption apply to both the home, the workplace (outside the conservation lab and inside it). Below is a list of energy saving tips from the U.S. Small Business Administration article Tips for Energy Efficiency edited for the conservation and collections workspaces in mind.

Resources from the scientific community discuss setting up and running a sustainable scientific laboratory. The type of information covered by these resources includes purchasing choices, resource conservation, and reducing the energy impact of lab spaces.

Here are further resources aimed at assisting scientists in developing a more sustainable laboratory.

  • Laboratory Energy Efficiency Profiler (LEEP) [1]
  • Energy Efficient Laboratory Equipment Wiki [2]
  • The Harvard Lab Sustainability Guide [3]
  • Image Permanence Institute's Sustainable Preservation Practices series, including webinars: Becoming Sustainable: Real-World Approaches and Introduction to Sustainable Practices in Environmental Management [4] and Sustainable Preservation Practices [5]

Climate Control, Heating, and Air Conditioning

Below are some tips for sustainable energy use for climate control.

  • Monitor and update your HVAC system annually to ensure it is running efficiently. An HVAC contractor who does "pre-season" maintenance ensures that your system is working at its best when it needs to the most, saving energy and money during the cooling and heating seasons while also prolonging the life of your system.
  • During peak seasons regularly change (or clean if reusable) HVAC filters monthly. A new filter will cost you less than forcing your system to work with a clogged or dirty filter. This also improved your indoor air quality for people and the collection.
  • If your workspace has windows use the direct sunlight to your advantage. During cooling seasons block direct sunlight shining through the windows on the east and west sides. During heating seasons take advantage of the sun low in the south by unobstructing southern windows.
  • Likewise regulate the temperature indoors through ways that don't rely on your HVAC system. A space fan during cooling months is often more energy efficient than having your air conditioner regulating the temperature for whole rooms or buildings. Plugging air leaks with weather stripping, caulking, or even closing doors will help manage your ventilation more deliberately.

Environmental Controls

The maintenance of correct environmental conditions can prevent the need for expensive conservation intervention and is a more cost-effective way to manage a collection (Brimblecombe 2005). There has been constant debate as to the need and details of such recommendations, as well as the best way to design a system to meet these recommendations (Levin and Maekawa 2007, Kerscher 1992, Bullock 2009, Rawlins 1942).

It has been accepted that light and high temperatures will speed up degradation processes, and high humidity (above 65% RH) will encourage mold growth. Art collections appear to be less sensitive to temperature levels than humidity levels, and “safe levels” are material dependent (Ayers, et al 1988). High risks begin outside of the range of 25-75% RH (Michalski 1993) and for general collections a more conservative estimate is recommended from 30-60% RH (Erhardt, et al 2007).

Collections are typically controlled by having a set point for temperature (usually 70°F) and humidity (usually 50% RH). It has been widely believed that this set point will then allow some deviation but it will create a safe environment for most collection materials(Erhardt, et al 2007, Anderson and Kestner. 2003). It has been widely discussed for some time how rigid adherence to these two points is neither better for the collection or for energy use. Alternative approaches to environmental control have been suggested using a cost-benefit analysis of RH levels, depending on what is possible from the building envelope and HVAC system and for the collections(Kerscher 1992). Appropriate decisions can be based on the knowledge that every 5°C drop in temperature cuts deterioration rates in half, and low RH is preferable for some collections (Michalski 1993).

For more information, please see the Environmental Guidelines section of this wiki. Also, in 2012, the Image Permanence Institute published a comprehensive look at this topic, called 'IPI’s Guide to Sustainable Preservation Practices for Managing Storage Environments' [6]

Office and Lab Equipment

Below are some tips for sustainable energy use for office and lab equipment.

  • Use ENERGY STAR or other accredited energy-efficient brand of equipment. This applies to everything from extension cords and desk lamps to ceiling fans, copiers and freezers.
  • Turn off machines and equipment when not in use. This is especially true overnight and on weekends. This also has the added benefit of prolonging the life of all machines and equipment. It is a common misconception that equipment lasts longer if it is never turned off; this is incorrect.
  • Turning off lab and office equipment when not in use. Many will appear off but are actually in standby, unnecessarily using energy. Consider a "turn me off" sticker as a reminder.
  • In many cases it is also beneficial to unplug electronics to avoid using "phantom" energy, which is when an appliance draws a small amount of energy even when turned off. A power strip with an on/off switch will make this easier in some cases if the outlet is inaccessible.
  • Use rechargeable electronics and batteries when possible. Disposable batteries are often more expensive and less energy-efficient.
  • Use sleep mode or turn your monitors off instead of using a screensaver.
  • Use a timer or visual sticker for lab and office equipment that can easily be left on after use.
  • Return frequently used equipment, such as computers, to standby mode when not in use.
  • Close the sash on fume hoods - this can be a very big energy saver!
  • Defrost freezers yearly and check that the door seals properly.

Lighting

Below are some tips for sustainable energy use for lighting.

  • Turn off lights when not in use.
  • When possible turn on localized lighting rather than lighting a whole room. Do not "over-light" a room.
  • Consider a "lights off" sticker on light switches and doors as a reminder.
  • Replace incandescent light bulbs with ENERGY STAR qualified fluorescent lamps (CFLs) when appropriate. CFLs cost about 75% less to operate and last 10x longer.
  • Use occupancy sensors; place lights on motion sensors.
  • When possible use natural light instead of lightbulbs.
  • Install ENERGY STAR qualified exit signs.
  • When installing new lighting systems, work with companies that promote sustainability in their work and core values, and ask for energy efficiency data from previous work with museums.

Lighting Choices

MR-16 halogen lights

MR-16 halogen lights, like traditional incandescent lights, create light through heating a tungsten filament. Although they last longer than incandescent lights, about 90% of the energy they emit is through heat, making them not as energy efficient as fluorescent lights or LEDs. Although MR-16 lights are in common use, they may not always be the "museum standard" for illuminating art. They may be best used as accent lighting when an alternative light source is not an option.

LED Lights

Most recently, discussions have centered on rapidly evolving LED light technology. There are many factors to consider for museum LED applications, including the potential for LED light sources to damage light-sensitive artifacts, metrics for comparing LEDs along with other light sources currently used, initial installation costs, and life cycle costs. We are grateful to Steve Weintraub for providing information (Download PDF) on this light source. He also notes there are still reasons to be wary of the technology at this point as more research continues. Jim Druzik, Getty Senior Scientist, in a recent CoOL post, said "We urge any organization currently using or interested in using LEDs to do some basic analysis of each LED product under consideration....In the near future, the Research and Technical Studies group of the American Institute of Conservation will take up just how they may facilitate and provide such a shared environment.” With careful research and planning, however, LEDs can be a safe and attractive lighting option for museum displays. Some museums have already implemented LED lighting for some exhibits, such as the Shelburne Museum's collection of dolls, doll houses, miniature interiors, and samplers.


MR16 LED lamp with GU5 3 socket.png For more info on LEDs...

  • Read Victoria Montana Ryan's review of the webinar Introduction to LED Lighting, moderated by Heritage Preservation [7] and presented by the Connecting to Collections Online Community [8]. Or follow this link [9] to the recording of the webinar, and other resources.
  • Read the summary or view vidoes of the presentations from the 2013 conference Gallery Illumination: LED Lighting in Today's Museums:[10].

CFLs (compact fluorescent lights) are also more energy efficient than tungsten-reliant bulbs. They are being tested and used in the museum environment. Many types of new fluorescent lights (especially T2, T5, and T8, as well as the "wide-spiral" compact fluorescents) offer a high degree of light quality and color correctness (Pfeiffer 2008). Fluorescents emit approximately 70% of their energy as light rather than heat. They also last longer than incandescent or halogen bulbs.

Disposal of CFLs can be a problem because of their mercury content. A typical fluorescent bulb contains approx. 20 mg of mercury, while low-mercury bulbs contain 4 mg or less. Approximately 620 million fluorescent bulbs are discarded yearly. Only about 20% of the discarded bulbs are recycled nationally. Discarded fluorescent bulbs release approximately 2 to 4 tons/year of mercury in the US. Although mercury disposal is a great potential environmental and health hazard, the potential damage from CFL disposal is less than the hazardous amounts of mercury generated by the coal-burning plants required to generate electricity to run the much less efficient tungsten lights, so: less electricity, less mercury.

Energy-Efficient Lighting Control Strategies

Lighting Control Strategies include:

  • Daylight control
  • Time-based control
  • Occupancy-linked control

Daylighting presents problems for energy-conscious design in institutions such as museums. Daylight almost always highlights architectural surfaces instead of the items on display, which in turn leads to an increased electric lighting load to counter-balance this effect (Lull 2008).

Time-based control requires either the use of an automatic timer, or reliance on individuals to turn lights on and off at appropriate times to save energy.

Occupancy-linked controls may rely on motion detectors or a combination of motion detectors and personal controls (such as the DALI system [11]). This type of lighting control is obviously best suited for areas which are not occupied consistently throughout the work day, but may receive frequent or infrequent visitors. Patricia Silence, Conservator of Museum Exhibitions and Historic Interiors at Colonial Williamsburg, urges the consideration of motion detectors as a means to reduce light exposure for collections as well as to save on energy costs. Her institution tried using motion activated sensors in two galleries where paper and textiles are exhibited. The below image shows a control panel for the lights (left) and the time clock which an electrican hooked up to the light panel (right). Photo credit: Patricia Silence, Colonial Williamsburg Foundation.

LightPanel-CWFoundation1.jpg

The time clock runs forward whenever the light is on in a particular case; therefore, the clock tracks the real-time hours that the lights are on. This system shows that the gallery is lit only 40% of the time, even with high visitation seven days per week. Patricia Silence identifies a four-way benefit from using this system: (1) energy savings when the lights are off; (2) energy savings when the chillers don't have to work so hard to compensate for the heat load generated by the lights; (3) extension of the life of the collections, which are exposed to radiation only when someone is in the room; (4) the threshold of acceptable light exposure for exhibit items is approached more slowly, which in turn means that exhibit changes are required less frequently, saving materials and labor (Silence 2012).

Case Studies: Sustainability and Energy Use

The Museum of Modern Art Energy Savings with Solar Panels and White Roof Solar panels QNS Dec 28th 005.jpg

In 2009, MoMA added solar panels to its offsite storage location in Queens, known as MoMA QNS. [12] They are estimated to produce about 65 Mega Watt Hours of electricity each year, about 2% of the electricity bill for the building. It is estimated that it will be paid off in 15 years. In addition to the solar panels, the rest of the roof is painted white. [13] The white roof is part of a NYC program called ‘cool roofs’ which is a study to explore economical ways to reduce the ‘urban heat island effect’. Less heat is reflected and lower temperatures around intake ducts makes it easier to cool the building. The roof has a 30 year guarantee (twice that of a quote for a tar roof by the same company) and is over office spaces with no complaints of leaks.

This PowerPoint provides examples of other sustainable MoMA initiatives.

PhotoArts Imaging Renovation The following email was received from PhotoArts Imaging of Hattiesburg, MS, in response to the CSCP's 2011 survey on sustainability as an example of sustainable practices that would be a good example for others to follow:

When we rebuilt after losing our lab to Katrina, we used all steel construction with 8" depth in the exterior walls. These walls were lined with an R-19 plastic covered insulation on the steel with an R-19 wall insulation on the interior 1/2" sheetrock walls. There is an air space of 3"-4" that creates a pocket between them. The insulation that covers the exterior steel walls extends from foundation to apex of the roof (the building has a peak roof) where the front-to-rear ridge vent creates a draw for the heated air to leave the space.

There are vents in each gable end of the building & one contains a heat & humidity controlled fan that pulls in fresh air to ventilate the attic & storage space. The ceilings over the labs and the mezzanine have R-40 insulation. The 75% of the first floor is covered by the Mezzanine & has an R-16 insulation between them. The interior walls are all insulated with R-16.

The lights are color balanced and low UV output lights. Lights are not on when no one is in the lab/room.

There are filters in the four labs & the kitchen area. These filter out most of the chemicals & other impurities for our water. Some water is double filtered. We have an all-electric lab except the hot water, which are Rennai Commercial On-demand heaters run by propane which is fed by the on-site tank. This also fuels the full building & system generator that can operate the entire facility in case of an emergency power outage (storms). The utilities were all placed underground.

We spend between 10 - 12 cents per square foot per month on the electricity (which is a rural electric power association - higher than most companies). Our HVAC (which is in three zones in the building) keeps each zone at the desired temp & humidity and operates about 40% of the day. During the hottest parts of the summer & coldest parts of the winter, the systems operate about 60% of the day. The temperature in the labs, mezzanine, & main office/digital/conference areas does not range more than 2-3 degrees during a 24 hour period.

The_Shelburne_Museum and LED lights The Shelburne Museum uses LED lighting for its collection of dolls, doll houses, miniature interiors, and samplers. The LEDs have been illuminating the doll cases since 2004, and were chosen primarily because the lights needed to be installed inside the cases. The museum needed a lighting system that gave off little heat and could illuminate the dolls evenly from close range. After extensive research and testing of different lighting methods, Director of Preservation and Conservation Rick Kerschner chose LED bar lights from Prolume. [14] This podcast from 2008 outlines the process of selecting and installing the then cutting-edge technology, and the experiences over four years of use. [15] The first-generation LEDs unfortunately dimmed after three seasons of use, but were replaced under warranty by third-generation LEDs that feature improved technology for a longer life span. Shelburne Museum conservator Nancie Ravenel writes that the new LEDs have been in place for over three years with no loss of intensity. [16] Furthermore, the new LEDs are brighter than needed for illuminating the collections, so they are on dimmer switches. When the LEDs do begin to dim, the switches can be turned up, further extending the life of the bulbs.

University of Michigan’s Harlan Hatcher Graduate Library HVAC System In 2008 the University of Michigan completely replaced the HVAC system for a small collection room ("The Environmental Room") housing papyrus and vellum manuscripts using a sustainable, energy-saving HVAC design. Details in this article. [17]

The Minnesota Historical Society's energy efficiency efforts. [18]

The National Trust, UK energy efficiency efforts. [19]

Small Corp [20] manufactures frames and display cases, and is completely powered by a photovoltaic solar powered system and composts all of its waste wood locally.