Refrigerator Modifications Blog Update - Evaporator Ice

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knotmeter
Posts: 8
Joined: Wed Nov 02, 2005 5:30 pm

Refrigerator Modifications Blog Update - Evaporator Ice

Post by knotmeter »

Even after all the modification I have made to my freezer in the refigeration blog I was still getting one inch of ice on the evaporator after two weeks. I found the problem and came up with a fix. I now only have a light coating of frost after 10 days and my freezer is 10 degrees colder.

This has by far been the best modification I have done.

The web page below shows what I did.

https://home.comcast.net/~teriwhine/frig.htm

Michael Bourassa
Inamorata Hull 148
Grapevine, Texas
Hans Grasman

Post by Hans Grasman »

Thank you Michael for supplying all the detail on how you made the fix.
I copied all 11 pages and will tackle the job when I get back to Florida in October.
It looks like your approach is the best we have seen on this message board.
Do you actually go on the lake in Grapevine for a sail in 100 plus degree weather?
Thanks again for your volunteer effort to share this with us.
IvanaU
Posts: 4
Joined: Sun May 11, 2008 10:30 am

Re: Refrigerator Modifications Blog Update - Evaporator Ice

Post by IvanaU »

I tried to access the web page and got an error message. Is it still a viable site? I would love to see what he posted.
Hans Grasman

Re: Refrigerator Modifications Blog Update - Evaporator Ice

Post by Hans Grasman »

Ivana
I found the old posting. Here it is:
Catalina 350 Refrigeration BLOG


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Latest Update

Even with all the modifications I have done on the freezer I was still getting one inch of ice on the evaporator after two weeks. Even if I was not opening the freezer door. There was an air leak somewhere which was letting moisture in.

If you look under the lip of the freezer and frig hatches you will find this is the thinnest place on the boxes. Also if you put your finger up in the corner you will find a hole in each corner. This is where the air was coming in.

I had originally put pipe insulation tape under this area, but when I pealed it off it was all wet. Which meant it was not stopping the moisture form getting into the box.

I used DAP low expanding foam to seal each corner and then put a bead under the lip around the hatch to increase the insulation. Make sure you do this to both hatch openings. Check out the pictures below.

You have to let the foam cure overnight with the freezer off and the hatches open.

After doing the above my evaporator has a light coating of frost after 10 days. And best part is my freezer is running 10 degrees colder.

During the last 10 days it has been above 100 degrees here in Texas and some days 105. I don't leave the A/C on in the boat so the cabin temperature is some time 100 degrees. During this time the freezer was 30 degrees max during the day and down to 10 degrees at night.

This was by far the best thing I have done to increase the performance of the freezer.

Michael Bourassa
Inamorata
Grapevine, Texas
Hull 148
Knotmeter@yahoo.com



Arrow point to where you will find holes in each corner





This picture is after the foam is applied under the lip and corners



This is the DAP low expanding foam I used. You can trowel it with a putty knife before it sets up.




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Original Post

I have Catalina 350 Hull number 148. When I got my boat the freezer would not go below 38 degrees and the refrigerator was over 50 degrees. I sail on Lake Grapevine which is in Texas, just above the DFW airport. The summers here are hot, its mid July now and we have had a string of over 100 degree days. Today its going to be 106.

Starting this spring I made some changes to the refrigeration system to see if I could get it to keep bags of ice frozen in the freezer during the summer.

This picture was taken July 17th. The top temperature is the freezer temp. The bottom temp is the temperature inside the boat. It was 102 outside. I don't keep the A/C on when I'm not at the boat. The temp in the refrigerator is 43 degrees.



I am going to go thru all the modification I made.

You should get a digital temperature gauge with a external probe so that you can check how your system is performing.

The first thing to do is put the temperature probe on the evaporator in the freezer with the door closed to see what your evaporator temperature is. It should be zero degrees or colder. Mine is minus 5 degrees now. But it was 20 degrees above before I had the freon level checked. The system only has 80 grams of freon, so its very had to get it balanced.

After adjusting the freon level the freezer was colder but still not keeping ice frozen.

Next I put in the Alder Barber vent kit on the compressor. The way the compressor comes the fan blows air thru the coils and over the compressor. So when I first installed the vent kit I had the end of the hose down in the bottom of the boat to pull in cooler air. This made the temperature go down in the freezer some more. But as summer went on and the temperature went up the hot air that came out of the compressor fan was being trapped in the compartment around the compressor. This made the efficiency go down.



Picture of compressor with vent hose kit

The Alder Barber manual says that you can take the compressor fan off and turn it around so that it blows air out over the coils and thru the hose. I did this and then disconnected the engine exhaust air hose from the stern exhaust port. Then I connected the compressor vent hose to the stern exhaust port. Now all the hot air is exhausted out of the boat. This really helped a lot. Now the freezer is freezing.



Above picture is vent kit hose connected to stern exhaust port.

Now your wondering what's going to happen to the engine exhaust air hose. The engine exhaust fan pulls air in from the port side and pushes hot air out the starboard side exhaust port. When you look in the compartment under the rear berth you see that the engine air exhaust hoses run out the back of the compartment into the stern. This area is not sealed and is wide open to the stern of the boat. Since there is lots of air coming in from the stern, the intake hose is not really doing anything because the system is not sealed. So I disconnected the starboard hose from the exhaust fan and connected the port hose up to it. Now the hot engine air goes out the port stern outlet. Leaving the starboard outlet available for the compressor vent hose.



This picture shows the switching of the engine vent hoses and the not used intake hose.

Next I used pipe insulation tape from Home Depot to seal all around the underside of the counter top. This area between the top door opening and the side wall of the freezer is the thinnest part and where the door hinges are mounted. Doing this made the door hinges stop sweating. (NOTE: Tape has been replaced by spray foam)

Also the divider panel between the freezer and the frig is not sealed. So even when you have the vent hole at the bottom closed, cold air seeps into the bottom of the refrigerator. So I sealed the divider panel with rope caulk. I left a small hole at the very bottom so water could drain out.

Another thing I do is keep two one gallon water jugs frozen in the freezer. The ice mass works like a holding plate and helps regulate the temperature. In fact the more stuff you put in the freezer the better it works.



Picture of pipe insulation tape under counter top in freezer (NOTE: Tape has been replaced by spray foam)

Next I added the black foam gasket around the lid insulation panels. When you close the door the insulation fits snuggly in the gap between the door and the counter top. This 5/8 inch black gasket material is available from Home Depot or Lowes



Picture of added gasket around door lid

The thinnest part of the refrigerator insulation is the door. I put a foam panel over it to increase the insulation. The added value of this is if you cut the foam to fit snuggly in the door opening it creates a second seal for the door. I always had a problem with the door gasket not sealing properly and leaking air. This stopped the air leak.



Picture of Foam Door insulation panel

All of the above modification made the freezer freeze even on 100 degree days without the cabin A/C on.

Some of this stuff may be a little crazy but its a good way to find out what works and what doesn't work.

Maybe Catalina can come up with a upgrade kit using some of these ideas.

I hope some of this will be of help to other 350 owners

Michael Bourassa
Inamorata
Grapevine, Texas
Hull 148
Knotmeter@yahoo.com
tjr350

Re: Refrigerator Modifications Blog Update - Evaporator Ice

Post by tjr350 »

Last year I discovered the gap located around the perimeter of the both the refrigerator and freezer doors. I had a lot of condensation on hot days on the countertop around those doors. Then I remembered a comment made by another owner as a fix. I went to Home depot in the electrical department and bought two packs of "Duct Seal". It is a black claylike material that is used to seal electric meters. It cost $1.99 per pack. I cut 3/4" strips and rolled it between my hands like clay to make long pieces. I then jammed the Duct Seal into the gap all the way around each door. I added extra into the areas near the hinges. The condensation is gone. Its a cheap fix.
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