Condensation on bulkhead forward of fridge

[Lady of the Lake]

When we first bought Lady of the Lake, we only used the fridge when we sailed her. Now, we are in a position to spend way more time on her and have decided to keep food and drink cold 24/7 so the fridge remains on continuously. Current draw is not the issue, all seems well with the equipment. However, now that the box is always cold, we are experiencing condensation around the box. Obviously I need to add more insulation if I am getting that much cold air through the sides of the box. But the one place that troubles me is the forward side of the box. That side is pressed up against the bulhkead between the galley and the port forward stateroom. Often, we experience moisture condensing on the stateroom wall directly forward of the fridge. I am concerned because of the potential for mold growth under the mattress but even more about the potential for rot and failure of the bulkhead. I have tried adding insulation to the inside of the fridge at that wall and it has reduced the condensation but has not eliminated it. Has anyone else experienced this and if so, any remedies?

Thanks,
Sam

[Cat Tales]

I'm glad this question is being asked because I'd also like to know the best way to add insulation to our fridge boxes.

We've been able to partially reduce (maybe by as much as 50%) moisture in the box by adding two small 12 volt fans. They circulate air constantly, thus creating wind chill which lessens the compressor run time. I don't have statistical figures to validate our results, but the concept is similar to a household refrigerator which dries out food vs. a deli case which is designed to keep products moist. Our fridge is the standard, front loading 9 cu. ft. box with no modifications except for the internal fans, and we've never had a condensation problem on the exterior of our fridge. If you decide to try internal fans, the trick is to have them constantly running when you turn on the refrigerator breaker. We've tried wiring them to turn on only with the compressor, but did not have noticeable results.

[Root]

We have not experienced the condensation issue you all are having up here in Virginia, but I did add insulation to our refrigerator just to reduce the run time of the compressor on Wind Seeker. We have the later upright model. Materials needed are one ¾ inch thick 4 x 8 sheet of Mylar faced Styrofoam board several cans of spray foam, box cutter, a long straight edge and disposable latex gloves. All available at Lowes, Home Depot and most hardware stores.

To access the back, top and sides of the refrigerator box, I cut a section out of the back of the settee about 8 inches high by 22 inches long directly behind it. Our upholstered settee sections are removable and held in place by Velcro so the hole created is hidden by the settee back. The bottom of the refrigerator is accessed by removing the cabinets below and adjacent to it. I used a “brick and mortar” installation method described below to apply strips of the Mylar faced Styrofoam in layers to the exterior of the refrigerator. The silver Mylar facing not only acts as a radiant reflector but keeps the foam strips from breaking when flexed.

Thin strips of foam board are easier to maneuver into place then larger pieces especially in the space between the box and the forward bulkhead. I cut 6 inch wide strips in lengths equal to the depth of the space being insulated from the Styrofoam board. These are your basic bricks and they can be trimmed to any size necessary.

Squirt a bead of spray foam onto an edge of a foam brick. Quickly slide the brick into place mortared edge first as far as it will go. This pushes the foam back toward the inaccessible areas where it will expand to fill any voids between the strips of foam and surrounding space and glues the brick into place. Repeat the process by adding spray foam to the abutting edges of the foam bricks and installing them until the sides of box are covered. Build out the thickness of the insulation, as far as space will allow, with subsequent layers of foam board repeating the methods above until the space is full. Use spray foam and pieces of foam board to fill any irregularly shaped space.

The installation of insulation is best done one side at a time as cured spray foam will hinder the sliding of additional foam strips into place. I started with the forward bulkhead side first, then the opposite side, then top, then bottom. Continue working until you have reached the maximum thickness of insulation possible for the space available all around the refrigerator exterior. Let it set up over night and trim excess to suit.

As you can imagine this is a very messy job. The spray foam is extremely sticky and will adhere to most any surface so clear out the settee area of very thing including the cushions and table before you start. Lay down a plastic drop cloth. You will need lots of rubber gloves. Neatness on finish does not count on this job as it is nearly impossible to make so. The job is not expensive, goes rather quickly and it will definitely improve the efficiency of your refrigerator. I know a picture is worth a thousand words and I will gladly send you photos. Email me your questions. Glad to help in anyway I can.

Ray

[Cat Tales]

Ray,

Did you consider removing the refrigerator box instead of cutting a hole in the settee?

[Root]

Oh Yah! I believe I took the easiest route, however. Moving the compressor lines, wiring and some how getting it all back in again did not appeal to me. The hole in the settee is not obtrusive at all. As a result of cutting an access hole, I discovered a lot of available storage space behind the settee so I cut another hole in the center portion only to discover in addition more storage space but the fluxgate compass for the auto helm mounted there near amidships on the forward transverse bulkhead. Ray

forward Storage Settee2.JPG (98.19 KiB) Viewed 7113 times