SPF and Kitty Litter Help Fix Produce Cooler
 

For natives of Tampa, Florida, being uncomfortable in the subtropical summer humidity is something they learn to live with. For Tola Produce, though, this heat was a problem. They’d been fighting condensation in the cooler for over 60 years. Finally, they found the right solution: spray polyurethane foam (SPF).

Because Tola’s produce cooler had been poorly insulated originally, the 2,000-square-foot (185.8m²) building was incapable of lowering to 35°F (1.7°C). This meant that the cooler had higher energy bills (from constantly running to try to reach that temperature) and higher temperatures than the owners wanted.

That, combined with neglected and deteriorated interior walls, indicated that the cooler clearly needed some care.



Chilly Introduction

With five days to re-insulate the cooler before it would be refilled with produce, a four-man crew from Alpha Spray Foam, Inc., headed in. The first task was to handle the disintegrating walls. Because they were far beyond repair, the cooling equipment needed to be shut down and removed, and the existing walls needed to be demolished.

“The entire cooler was pressure cleaned, and the mildew was treated,” says Alpha owner, Darrell North. “One wall of the cooler had to be removed and rebuilt due to moisture damage.”

Once the mildew-damaged areas were completely removed and discarded, a few members of the crew were able to return to install the new pressure-treated plywood. They rebuilt the section of a 20-foot-by-40-foot (6.1-meter-by-12.2-meter) wall with the pressure-treated framing and plywood.

Other team members started preparing the existing areas. They covered the fixtures attached to the cooling equipment with plastic and tape, and they installed painted aluminum around the perimeter of the single door jam. This trim piece fixture allowed foam to fill the two-inch-thick (5.1cm) channel while giving the door a smooth edge.

“It gives the owner a nice, clean edge,” explains North. “There’s no foam to damage around the edge.”

Cool, Calm, and Collected

The following day, the crew cleaned the walls. They used a 3,500psi (24.1MPa) pressure washer on the original metal, but they kept the new plywood dry.

Because they had anticipated that the pressure washer would cause some ponding, they brought in four 48-inch (121.9cm) fans to circulate the still-hot air. Unfortunately, after hours spent mopping up the water on the cooler’s floor and running the fans, the crew noticed what would become one of the most challenging parts of this job.

Not only was the water not going anywhere, but it was growing. After only a few hours, what started at one-eighth inch (0.32cm) grew to one-half inch (1.3cm). They learned that the humidity of the air, the heat from the workers and equipment, and the cooling temperature of the nearly frozen floor combined to create condensation. That was a problem.

This unusual problem called for an unusual solution.

“We ended up using a lot of kitty litter to create a dam at the perimeter so the water wouldn't affect the walls,” says North. “We’d tried a few techniques, and we settled on using several hundred pounds of kitty litter. Then we’d hand dry and air dry the wall once the kitty litter had soaked up the condensation on the floor.”

Unfortunately, this extra step meant extra time.

Staying Ahead

When the crew returned on the third day, they masked the light fixtures and got ready to prime. It took one crew member three hours to create a surface ready to be foamed. Since the walls were 20 feet (6.1m) tall, the applicator needed a two-tier rolling scaffold to reach the top of the cooler. With a safety railing and a person on the ground moving the scaffolding, the applicator was ready to go.

Using a Graco airless sprayer and 100 feet (30.5m) of hose, they applied five mils (0.13mm) DFT of primer. Even though the other crew members continued mopping the floor, there was enough circulation of air to allow the primer to cure in just a couple of hours.

While one applicator primed a 15-foot (4.6m) section of the wall, someone else was preparing the next 15-foot (4.6m) section. Preparations included dropping kitty litter at the bottom of the section, soaking up the standing water, and then disposing of the litter. That way, the floor and the bottom section of the wall were dry by the time the applicator was ready to spray.

By the end of the day, the crew had the system and the primer down.
   
Beat the Heat

Although working in a cooler sounds like a chill time, combating the 100°F (37.8°C) interior temperatures was a challenge for the crew. They wore air-powered cooling vests from Allegro to help. Attached by a 200-foot (61.0m) air line, the cooling vests (along with ice packs, Sprayfoamgear.com’s Value coveralls, and Bullard air-supplied respirators) supplied the means for the workers to move onto the foam.

The sprayer applied three inches (7.6cm) of foam to the cooler’s ceiling. Using a Graco E30, P2 gun, and 300 feet (91.4m) of heated hose, they applied BaySystems’ Bayseal CC closed-cell SPF (formerly DuraSeal). Applying more than two inches of the closed-cell foam, meant that the foam itself acted as a vapor retarder.

With the aid of the blowing fans, the crew left the ceiling to cure overnight before moving on to the walls.

On the second-to-last day on the job, the crew had a long list of tasks. They finished spraying all of the walls, inspecting the cooler for rough edges, and spraying a flash coat of foam over grounded spots. This ensured a “smooth, scrubbable, cleanable surface,” as North explains, and got the foam ready for the topcoat.

On the final day, the crew used a Graco HydroMax sprayer to apply 16 mils (0.41mm) DFT of Bayblock I acrylic elastomeric coating (formerly DuraShield). While it cured, the crew removed masking on the walls, and they swept, vacuumed, and mopped the floors one last time to chase any of the remaining kitty litter outside.

With the fans left running for another two days, the crew headed out of the cooler. Before signing off on this job, the cooling units were reinstalled, and the SPF contractor ensured one more problem was handled.

Since one of the main causes of destruction to the initial insulation was the forklift running into walls, the Alpha crew had the owner add concrete parking lot bumpers around the edge of the room. This protected the SPF-covered walls as well as allowed the proper amount of space between the produce and walls for circulation.

At the end of the job, the cooler was finally insulated. For the first time in 60 years, the building was able to drop all the way down to the desired 35°F (1.7°C) and cycle on and off.

“The owner was so impressed with the job and the cooler, he had us foam one of his uninsulated delivery trucks, and then he had us rebuild and re-foam another small 400-square-foot cooler (37.2m²),” exclaims North. It was a cool job for this cool crew.
 

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