Post Date: 09/28/21
Over the last three articles in this series, we have focused on the benefits and challenges of converting to LED. In our first article, we outlined the cost benefits of converting from Halogen to LED replacement lamps. In our second article, we went over some of the potential challenges related to the use of LED replacement lamps in legacy Halogen infrastructures. Our third and most recent article addressed the advantages of Integrated LED sources, and the design strategies that they support. In this last article, we are going to review some of the cost benefits of an integrated solution, and review some of the compelling reasons behind converting to LED.
LED Museum Lighting: Why Convert?
We were recently talking with the Exhibition Production Manager, Brian Balderston, at the Queens Museum. In 2020, the museum had secured a city-based grant to convert their old Halogen infrastructure to LED. The grant was premised on the significant energy savings that the conversion would provide. Litelab worked with the Museum to ensure that the upgrade would not only provide the desired light output and energy savings, but would also fall within the budgetary allocation of the grant.
To upgrade their infrastructure, the museum used a combination of C71, C72 and C73 fixtures, along with a custom high-output M75 fixture that was designed to replace existing PAR56 Halogen fixtures. These fixtures are located approximately 35’ above the finished floor in the main space of the 2010 Expansion designed by Grimshaw Architects, with lighting design by George Sexton Associates. The original space dates back to the 1939 World’s Fair, and houses an incredible panorama of New York City.
In talking with Brian, he commented that before converting to LED, he was replacing 500 Watt PAR56 lamps in the main space almost monthly. In addition to the PAR56 lamps, he was also regularly replacing the 250 Watt PAR38 lamps that lit the tall lantern space used for large-scale three-dimensional art exhibitions. Both spaces require using a tall lift to reach the fixtures, which are nestled near the corners of skylights. Time and labor replacing these lamps represented a significant resource commitment, which added to the material cost of changing the lamps, and prevented Brian from focusing his expertise on more challenging questions related to exhibition at the museum.
After the conversion, several benefits of LED lighting presented themselves:
First, energy consumption plummeted from approximately 89,540 kWh/year to 9,386 kWh/year based on a use-case of 27 hours / week (the total number of hours that the museum is open every week). Using the cost of electricity provided in the first article in this series (10.5 cents / kWh), this equals a total annual savings of approximately $8,424.00 / year.
Second, the LEDs used have a conservative LM-70 of 50,000 hours, compared to an average of 2,000 hours for the Halogen lamps that they replaced. Based on a use-case of 27 hours / week, life expectancy for the LEDs would range around 35 years. Conversely, with a Halogen infrastructure, the museum would have to change lamps once a year. At an average of approximately $15.00 / lamp, with an infrastructure of approximately 250 luminaires, total material cost of re-lamping the space would be around $3,750.00. Over an expected lifetime period for the LED fixtures of 35 years, this equals $131,250.00 in lamps alone, assuming price stability (which is unlikely as halogen becomes less common).
Third, in addition to energy and material costs, there is also the cost of labor to install the lamps. As described in the first article in this series, labor cost can use a base pay rate of around $45.00 / hour, with an estimated time of 8 minutes / lamp, resulting in an additional cost / lamp of $5.99 for the labor to change lamps. However, since the Queens Museum of Art has a large quantity of lamps located in a very tall ceiling that require a lift, we will adjust this estimate to account for the use of the lift to about 10 minutes / lamp, which would result in an estimated cost / lamp of approximately $7.50. Labor cost to re-lamp the museum would equal $1,875.00 / year. Again, over a period of 35 years, this would equate to around $65,625.00, assuming a stable rate of pay over that time.
Putting this all together over the lifetime of the new LED fixtures, total monetary savings will accrue to $491,715.00 in energy, material, and labor costs. Remember that the Queens Museum also used grants provided by the City of New York to purchase the new fixtures. As a result, the material cost associated with converting to LEDs would equal the amount of time and effort taken to submit the application. The new installation will also save 2,805,390 kWh over the lifetime of the new fixtures, while reducing untracked costs, like those associated with HVAC loads, especially in warmer seasons. In addition to saving energy, labor, and money, the new installation frees the Facilities and Exhibition teams to focus on other aspects of the museum’s performance and presentation.
Benefits of LED Lighting rather than Replacement LED
As we discussed in the last article, a number of variables go into the decision-making behind choosing a lighting infrastructure. In the case of the Queens Museum, cost, performance, and long-term stability were incredibly important in their decision making. One of the major challenges for the Museum was matching the performance profiles for the very high output PAR56 and PAR38 fixtures, while maintaining very good (90+) CRI.
While there are PAR56 and PAR38 LED replacement lamps, they do not meet the performance capabilities of the Halogen lamps that they were designed to replace. As a result, in addition to the cost of lamps, there would have been additional costs associated with purchasing new LED Replacement lamp fixtures to supplement the lower output of the old Halogen infrastructure. More importantly, the Halogen fixtures used by the museum did not have any ventilation for LED replacement lamps. This would have seriously compromised the lifetime expectancy of these lamps, leaving the Museum three choices:
Purchase all new LED Replacement lamp fixtures and lamps, which would have cost roughly equal purchasing new Integral LED fixtures
Use much lower output lamps rated for fully enclosed fixtures, along with additional fixtures and lamps to supplement the comparatively low output of the LED replacement lamps
Purchase an Integral LED solution that would match or exceed the performance profile of the existing Halogen infrastructure
Since both LED replacement lamp solutions required the addition of fixtures that offset the price competitiveness of this solution, an Integral LED solution seemed appropriate. With features like on-board, fixture-by-fixture control and zoomable optics, which are not available for LED replacement lamps, the Integral LED solution became even more attractive. In the end, based on the performance requirements of the space, the overall cost and the long-term infrastructural stability of the Integral LED solution, the museum opted for the Integrated LED option.
The Queens Museum is not the only mid-to-small cultural institution attracted by the long-term energy, labor, and material savings of LED museum lighting. The museum was fortunate to take advantage of grant programs to pay for their conversion during Covid-19 lockdowns that kept many museums closed and struggling financially. Across the United States today, many local municipalities, Counties, States, and energy providers are offering incentives to residents and institutions to lower the power strain on electrical grids, and reduce regional carbon footprints in response to global warming. These incentives come in many forms, including grants, tax-credits, and rebates.
When reviewing alternative lighting options, be sure to account not only for comparable performance, but life-time savings. As outlined throughout this four-part series, the benefits of led lighting come in numerous forms: energy consumption, material and labor costs, strain on building infrastructures and even on facilities and exhibition resources that could be better allocated elsewhere. It is advisable to partner with a lighting manufacturer who is willing to work with you to provide or create critical data to inform your decision, including things like LM-70 reports on lifetime expectancy, photometric data on the performance of fixtures, cost analysis based on different options, and even conservancy information where conservation is a concern. Doing so will help inform fundraising and budgetary efforts, while also ensuring that final performance matches your institution’s needs.