The Greening Of A Warehouse
Robert “Bob” Footlik and his late father, Irving, are virtually without dispute the most renowned and prolific warehouse architects and material handling consultants our industry has ever known. Their imprint is on hundreds of buildings operated by Supply House Times readers, as well as clients in other distribution industries.
An interesting aspect to their business is how many of their ideas grew out of personal experiments. In 1963, Irving Footlik decided to develop an industrial building in the Chicago suburb of Des Plaines as both an investment and a “living laboratory” for new construction techniques. Many aspects of warehouse design that were state-of-the-art in decades past no longer make sense. In particular this applies to HVAC and lighting, whose energy consumption used to be of minor concern.
Various tenants have occupied Footlik’s 75,000-sq.-ft. building over the years, the most recent being a roofing supply house that left in 2006. The economy being what it is, the building has stayed vacant longer than the owner would prefer, but instead of cursing the emptiness Footlik decided to light a big green candle by bringing the building up to modern standards in every aspect - especially with regard to energy efficiency.
Footlik calculates that the savings generated by his improvements amount to between $1.00-$1.50 per square foot in annual operating costs. What follows is a description of some of the major reconstructions done to the building to reduce energy costs and enhance operating efficiency.
Air rotation heaterAfter the last tenant left, 11 inefficient unit heaters were replaced with a single Johnson Air Rotation unit to serve the entire warehouse area. “A major problem with any warehouse unit heater is that this equipment uses a small fan that fails to push the heat down to the floor,” he explained. “Maintaining 60 degrees at floor level may require holding 75+ degrees at the ceiling.
“In addition, the six-inch diameter flues siphon this heat to the outside whether the heaters are running or off,” he added. “The net result is heat loss and air stratification. The air rotator uses a higher temperature heat exchanger and exhaust control so heat losses out the stack are minimized.”
While touring his building with me, Footlik used a laser temperature sensor to demonstrate. In an unrenovated former boiler room that is closed off, he measured temperature differences of 15-20 degrees between ceiling and eye level. In the main warehouse heated by the air rotator the differential declined to 2-3 degrees.
“The air rotator will scavenge heat off of any ancillary source, including human bodies and what comes off of translucent plastic around the upper walls,” he said. “Installation of a single high-efficiency air rotator up-flow furnace sacrifices 150 square feet of floor area, but replaces multiple inefficient unit heaters scattered throughout the space. Our experience is that even on the coldest days the temperature will be constant from the front of the building to the rear, and from floor to ceiling. Running the fan continuously year-round will also keep the warehouse cooler in the summer, and with air filters installed, dust and dirt are greatly reduced,” said Footlik.
“This is something I’d recommend just about any place in the country, with the possible exception of Hawaii,” he noted. “In the South, an air rotator circulates air in climates that are humid, enhancing comfort for personnel. In a real hot climate like Arizona, where you’ll typically have an evaporative cooling system, the system can be used with 'duct sox' to blow air across the building at no big expense.”
He also replaced office HVAC equipment by installing a 95% efficient rooftop unit to replace a 45-year-old furnace that had been rebuilt multiple times. The improvement was immediately obvious in terms of comfort and cost of operation.
A low-tech enhancementA design innovation favored by Bob’s father, Irving, was “daylight harvesting.” This reduces electrical energy consumption while simultaneously enhancing morale. It involves surrounding the upper walls with a 4-ft. high translucent corrugated plastic ribbon to achieve a natural lighting effect inside the warehouse. This let in light, which was good, but let out heat, which wasn’t a big factor when the building was first built but is bad nowadays. “My father was well ahead of his time,” Bob noted. “What he lacked was the technology to make it more effective.”
The “technology” selected by the son is nothing more than bubble wrap, which he found out has a higher R rating than metal or block walls. “Bubble wrap cut our heat losses enormously,” he said - and at a trivial cost of around $400 for the 4,300 sq. ft. of windows, or less than 10 cents per square foot. “Bubble wrap is not UV-stabilized and I have no idea what the deterioration rate is, which is part of our experiment. A farm supply company offers a similar product made for greenhouses that is UV-stabilized but costs 10 times more. That’s still not a bad price.
“Achieving this level of natural lighting in a building with skylights would require over two hundred 4-ft. by 4-ft. units. The light quality from skylights might be better because more light reaches the interior, but the potential for leakage from all the roof penetrations would be totally unacceptable,” he offered.
Sensor lightingNext to HVAC, lighting offers the greatest opportunity for energy savings in a warehouse. Footlik replaced old light fixtures with energy-saving T-5 lamps and ballasts, with occupancy controls to turn on only the fixtures required when a worker is in the vicinity - or not at all if sufficient daylight is available.
Passive infrared motion detectors turn on the lights whenever someone enters an area, and turn off the fixture anywhere from 30 seconds to 12 minutes (depending on settings) after they leave. On one side of his building the fixtures were arranged in units of three that turn on and off in response to motion. Along the way he learned that the motion sensors are relatively inexpensive compared with other installation and material costs, so in the rest of the warehouse he attached each light fixture to a sensor. In a supply house setting, many times a warehouse worker will only go to a single bin or shelf location near the front of an aisle. Instead of setting off the entire row of lights, only one localized fixture will turn on.
According to Footlik, sensor lighting offers some of the best bang for the buck in terms of payback. He cited one client building in which the payback on the sensors was less than two months. “The fixtures came on less than 10% of the time, and the company’s per-fixture electric bill went from $40 a month to less than $4,” he said. For his own building, he claims that occupancy lighting actually ended up making money for him once he cashed in a federal tax credit and power company rebate.
Besides saving energy, sensor lighting accrues security benefits. “You can always tell where your people are,” Footlik noted, “and if someone breaks in, well, most burglars don’t like to work when the lights are on!” Moreover, sensor lighting is relatively easy to retrofit because you can do one fixture at a time to minimize disrupting operations.
Footlik shared that when putting in the lighting, he also added an 18-kw, 80-amp. backup generator. “That’s enough power to run the air conditioning, computers and the telephones. It cost us little more than a few bucks for the wiring, but I don’t know of any client who wouldn’t like to have a backup generator. It’s something to keep in mind when doing an energy changeover - think about what else you can bring in at little extra cost that would be nice to have.”
Main electrical roomThis part of the lab building’s renovation was driven not so much by green considerations as necessity to meet modern electrical codes and requirements, although significant energy savings also result. Important features include:
The total time required to do this work was over 10 months, thanks mainly to wrangles with corporate and government bureaucracy. “It was a prolonged and agonizing process involving multiple submissions and forms, a sign-off by the Des Plaines electrical inspector and a ComEd crew that was ready to walk off the job for lack of a couple of bolts.”
Shocking the shell“Examine the roof,” Footlik advised. “If it is over 20 years old, replacing it will ensure that the space below will be warmer in the winter, cooler in the summer and always dry.”
In 2007 the roof of his lab building was completely removed down to the bare steel panels. Anything rusty or weak was replaced and covered with two inches of high-performance rigid cellular insulation and a fully adhered, state-of-the-art membrane fabric roof with a heat-reflecting, monolithic white surface. Every extraneous opening was filled in to eliminate heat loss.
The underside of the roof deck was thoroughly power washed and painted with Sherwin-Williams “dry fall” fine powdery coating to increase light reflection, reduce glare and enhance energy efficiency. “The end result is a structure equal to any contemporary building and major energy cost reductions,” said Footlik.
Walls and ceilings also were power washed to remove built-up dust and dirt, and as a prelude to spray painting with a high-volume, low-pressure system. “This is the best application method for the ‘dry fall’ paint we applied,” he said. “This finish not only enhances the aesthetics, it is also a key component of the new lighting system. The high output, fluorescent fixtures have openings to allow for up-lighting to reduce glare and enhance the lighting effect. An added benefit is that laminar airflow across the lamps will keep the reflectors and lamps cleaner.” He cautions that this painting process is not something to try in an existing building, because “it makes a mess.”
The bottom five feet of the interior walls in his lab building are painted blue for visual contrast and because it won’t show abuse as much as white. The remaining space above is painted white to brighten up the interior.
Docks & doors“Docks and drive-in doors are also a significant source of both energy waste and human inefficiency,” said Footlik. His lab building has new doors two inches thick, fully insulated and weather sealed. He also installed Kelley FX air lift dock boards, which operate much easier than manually operated boards and completely seal the pit opening to reduce air infiltration. It uses a little energy, but more importantly the air lift dock board offers great enhancements in safety and productivity.
Fire protectionThis part of the renovation was driven by necessity rather than energy efficiency. Footlik wanted to draw attention to it, however, because in order to get a building permit almost anywhere in the country a distributor will have to comply with similar provisions.
“Many of the buildings a wholesaler might consider will accommodate his materials, but with storage restrictions that use far more square feet,” he informed. “For instance, without an updated fire suppression sprinkler system under current interpretations of NFPA 13 even low-risk commodities might be limited in stacking height. This is an area where expert advice and interpretation by the local fire marshal is required.
“You can act as your own expert by looking for a backflow preventer near the point where the water main enters the building,” he continued. “An existing building might be grandfathered without this, but most municipalities will demand these check valves as a condition for obtaining a building or occupancy permit. No backflow prevention means that the system is no longer effective under today’s standards.”
Among the difficulties encountered for his building renovation was inadequate water pressure. Footlik discovered to his dismay that the building had only around 40 psi, which would not be enough for the fire pump to operate. “Most supply houses should be running 50-60 psi with 20-ft. ceiling height and a modest amount of plastics,” he said. “If in addition to PVC fittings you have a lot of fiberglass shower stalls and other plastics, then even 60 psi is not enough. Our new high-pressure system (120+ psi) supports full height stacking for most products with 8-ft. aisles.”
His renovation required over 700 sprinkler heads, 2,500 ft. of piping and 500+ fittings to bring the system up to NFPA 13 code standards. It also included a new fire annunciator system with a radio link to the Des Plaines Fire Department; a separate, dedicated, fire system electrical service; a fire pump capable of high pressure and flow, along with a new controller to monitor and reliably maintain the system; a fireproof room and ceiling to house the system; new control boxes and a pump for landscape irrigation, also including backflow prevention; new domestic water service.
The net investment required to install these updates was over $150,000 and the time and effort required was a major commitment.
Final touchesAny warehouse with columns is going to receive its share of forklift dents and bruises over time. Misshapen columns are not only an eyesore, in some cases they can be damaged enough to threaten structural integrity. Footlik, working with a brother-in-law who happens to be a general contractor, devised a tool to straighten and reinforce columns without compromising warehouse space.
Footlik offered this piece of advice in closing: “If you’re going into a new building, that’s the time to get started on an energy improvement program. You can’t do a lot of things, like painting the ceiling, when the building is in operation. So be sure to do it when you’re moving in, or during some major upheaval, such as replacing a leaky roof. You cleared out everything underneath, so you might as well scrub the floor and clean everything up.
“Besides,” he concluded, “the insurance company might just pay for it!”