Shroud Mystery

Sunday was Father’s Day and also officially the first day of summer – the summer solstice. I had a couple of projects to tackle. Actually I combined the tasks as they both entailed getting up on the roof of our coach.

Last week, I ordered new shrouds that cover our rooftop air conditioning/heat pump units. The shrouds on our coach had cracked and needed to be replaced. I spent some time on the Internet trying to figure out which was the right part number to use. It was somewhat confusing. From what I gathered, I needed to order a shroud with the Dometic part number 3308047.012 to fit our Dometic Penguin 15,000 BTU units. However, I saw references to 3308047.006 and 3308047.020 and 3308047.032 – all saying it was the correct part for our unit.

I finally found a document that cleared up the matter. The last three digits are color codes in Dometic’s numbering scheme. All four of the shrouds are the same 3308047 but the .006 is shell white, the .012 is polar white, the .020 is gray and the .032 is black. The other thing that confused me was the appearance. Our current shrouds are solid with no vent holes. The replacement part has vent holes on the left side. Later I read that the solid shroud with no vents are early models – the vents were added later, but they’re dimensionally the same. The vent holes facilitate the exhaust of heated air drawn through the condenser.

The shrouds protect the mechanical parts of the air conditioning (A/C) unit and also ensure proper air flow through the condenser. A fan pulls air through the condenser coil which resembles a coolant radiator in your car. The refrigerant is a hot gas at this stage of the system – heat from the interior of the coach is transferred to the refrigerant. The condenser cools the hot gas and converts it back to a liquid.

Since the primary function of the shroud was to direct air flow through the condenser for cooling, it didn’t make sense to me to have a dark shroud on the roof absorbing heat from the sun. A white shroud that would reflect heat from the sun seems more sensible.

I ordered two polar white shrouds through Amazon. I received an order confirmation e-mail right away and the next day, I received shipping and tracking information. The order was being fulfilled by a third party – PPL RV Parts Superstore in Texas. Then things got interesting.

The FedEx tracking info showed the parts en route. On Thursday evening, when I tracked the shipment, it showed the parts in Springfield, Missouri (40 miles away from here) and said delivery was refused, package returning to shipper. What?

On Friday morning, I called Amazon customer service. The rep was helpful – she looked up the order and once she understood my problem, said she would contact the shipper. She sent PPL an e-mail and copied me. PPL was on top of it. A gal in their customer service department phoned me right away. Then she talked to FedEx. She called me back and said they tried to deliver in Hollister, but the package was back at their center in Springfield. She confirmed our address, then got our site number. She e-mailed me later telling me she had given the information to FedEx and asked them to write my site number on the packages.

On Saturday morning, I missed a call from FedEx. They left a message saying they would need my site number to deliver. Hmmm?? I called the number they left and got voice mail. I left my name, number, address and site number. I tried calling them seven times in the next 45 minutes and got voice mail every time. I sent this information to the gal at PPL. She called later and said she talked to FedEx again – they had the site number and it was out for delivery. I have to say PPL was very good at following up.

The packages showed up around 5pm Saturday afternoon. The site number was handwritten on the boxes. The message from FedEx Saturday morning remains a mystery, but I understand now why the packages were marked refused. My name and site number weren’t on the shipping label, just the name and address of the RV park. The RV park office didn’t know anything about the packages and they refused them. My phone number was on the label – all the driver had to do was call instead of returning the packages. I’m not sure if I made a mistake on the order or if PPL did, but PPL made sure I got the parts.

So Sunday morning, I broke out the extension ladder and got on the roof. The first order of business was to sweep the droppings from the mimosa tree from the top of the coach. This is the messiest tree I have ever parked near. Once I accomplished that, I set about replacing the shrouds.

After removing the front shroud, I cleaned the fins on the condenser with a stiff nylon brush. A lot of cottonwood fibers were on the fins. This is something I should do annually. There are 1″x1″ foam strips that seal the shroud to the condenser fan opening to ensure proper airflow. The new shroud came with about 100″ of 1″x1″ foam with adhesive backing. I cleaned the area where the foam adheres with alcohol, then applied the foam strips.

A/C with shroud removed and new foam seals applied

A/C with shroud removed and new foam seals applied

One of the things you run into with an older vehicle that has had more than one owner is poorly executed previous repair work. The screws holding the shroud to the frame on the front A/C were mismatched. Someone put oversized screws on the front, probably a result of stripping out the originals. The old screws were rusted and I wanted to replace them.

I set the new shroud in place, then scootered over to Lowes for hardware. Donna joined me and I dropped her off at Country Mart across the parking lot for a few groceries. I was pretty sure I needed two 14-3/4 sheet metal screws to fasten the front of the shroud and two 10-3/4 sheet metal screws for the rear of the shroud. The guy at the hardware aisle at Lowes looked at the old screws I brought with me and said I needed 1/4″ x 3/4 and 12-3/4. Since my eyes aren’t the best and he does this stuff all day, I took his word for it. When I returned and got up on the roof, I discovered that the new screws were too big. I needed 14-3/4 and 10-3/4 just like I thought. I kept the screws I just bought to add to my inventory and went back to Lowes to buy what I originally went there for.

With the right screws, I was able to finish the installation of the front A/C shroud. One of the things I did differently was to add 1″ fender washers under the flat-topped screw heads. The mounting holes in the molded plastic shroud are 1/4″ diameter and only have about 3/8″ margin to the edge of the shroud. This is poor engineering. The fender washers should spread the clamping load over a larger area and reduce the chances of premature cracking around the mounting holes.

Fender washers under the mounting screws

Fender washers under the mounting screws

I went to work on the rear A/C. I found different mounting screws on the rear unit. It had 12-3/4 and 10-3/4. This was probably the original size. I had what I needed on hand. The seals on the rear unit were in better shape but still needed to be replaced. I cleaned the condenser, replaced the seals and mounted the shroud. Job done!

New shroud in place

New shroud in place

Ols shroud painted brown with duct tape over the cracked mounting point. That's mimosa tree detritus on the tape

Old shroud painted brown with duct tape over the cracked mounting point. That’s mimosa tree detritus on the tape.

With the condensers cleaned and new foam seals and shrouds, the A/C units should operate more efficiently.

After I put my tools away and cleaned up, Donna made me a special Father’s Day lunch. She picked up smoked barbeque ribs at the Country Store. They have a big smoker in the lot in front of the store and make them onsite. She whipped up a potato salad from scratch and filled a plate for me. The ribs were tasty, but I was spoiled by the ribs at Blues City Cafe on Beale Street in Memphis. These were no match in the tenderness category.

Special Fathers Day lunch

Special Father’s Day lunch

I spent the afternoon kicking back and watching the Formula 1 race from Austria. I had calls from all three of my daughters wishing me a happy Father’s Day.

Donna outdid the purchased lunch by making baked shrimp with fennel and feta for dinner. Yum-yum.

Baked shrimp with fennel and feta

Baked shrimp with fennel and feta

It was a good day!

 

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