Unlike several of the other projects this was not on our planned list of projects. We use a version of SCRUM to plan out projects based on cost, time, and system critical nature. As an example to replace two compressor units on this project would be around $2000. The work units would be about 16 hours of time. The critical nature puts it at the top. In our case an “A” story line is life critical, safety, or survival. The “B” story line is necessity of comfort, cleanliness, and operation. The “C” storyline is all about wouldn’t it be nice and in general things that can be knocked out in a few minutes. The refrigeration issue wasn’t even on the SCRUM board.
One morning the lovely Sydney went to get something out from under the sink and she was met with water splashing out onto her feet. And the lovely aroma of salt water. This had her look into the cabinet to see the refrigeration quietly and happily filling the boat with salt water. How nice. We then discovered that we could close off the inlet to the sea but that the fridge, freezer, and stern toilet saltwater all came from the same through hull and there was not a manifold (allows for independent shut off) in place. Further the outlet for the systems was tied into another through hull and it too was not separately controlled. Off the fridge and all go and let defrost begin. We had discussed options for the future with a couple of companies thinking we wanted to put in a drawer fridge. We considered all of our options and came up with the following requirements.
- Get rid of another through hull go air cooled
- Install a system that is much more power svelte
- Make the change as simple as possible
- Get a warranty
The one unit was leaking at a junction. I would have figured that it was a metal piece that eroded from salt water and dissimilar metals. What appears to have happened is the fitting just gave up. I can hypothesize that it was caused by heating and cooling or something like that. However, there is no real reason that we could find for the failure.
Neither unit was a complete write off. A few parts on one and likely prophylactic replacement on the other and we would have been up and operating in a few hours. We decided that since we had them out it was better to just replace them and go with what we wanted in the end anyways. This got us a warranty and gave us a new system. Both units are substantially better at energy management. So, whereas it was a bit of a splurge we thought it was worthwhile to simply not be pumping water into the boat. We believe in rule 1 of boating, “Keep the water on the outside and the people on the inside.”
Getting to replace the strainer, and the through hull that serviced it was a “nice to have” result. As you can see in the above picture the feeds off the strainer are a bit of a mess. Because we also replaced the stern toilet the salt water feed shared at this point with fridge and freezer was an “also delete” that was already planned. On the next haul out the entire through hull will be covered over and fiberglassed closed. Even though it is a reinforced location we want the hole in the boat closed up.
We went ahead and installed a small high efficiency fan in the cupboard and will go ahead and stain the grills for the inlet and exhaust. The laminate was a real problem to cut but when stained it should have a very factory OEM look to it.
All in all with testing we were able to get much more efficient cooling via air cooled compressors and not heat load them even in a closed cabinet. The old system with just one compressor running and water pump used more power than the new one does with both of the new compressors, and the exhaust fan running. The cycle times are less running and less of them. The cooling performance is adequate and I’m not sure comparable. The new system uses a slightly higher setting for temp, but cools to that temperature much faster. I’m not really sure what that means. The total approximate costs for all of the labor and materials was $3000 and due to parts availability took a few weeks to complete. We ran the system without the fan and the door off the cabinet for a few weeks, and have had it running with the exhaust system in place similarly for a few weeks. Because of active air replacement with the fan I think heat loading is actually better than even having the entire door open.