Page 2 of 4

Re: Swap out a 12K unit with a 16?

Posted: August 5th, 2019, 6:57 am
by tonyiiiafl
I hope if you get here again we can meet up!

Re: Swap out a 12K unit with a 16?

Posted: August 6th, 2019, 2:28 pm
by buster53
tonyiiiafl wrote:Qr Bbpost I also have a 16 forward and a 12 aft. On a hot summer day they do struggle. Same at night though they are fine. Tough choice here as the replacement cost is really negligible of 12 versus 16.


From the size of your actual cabin space, your 39' is probably the same as my 35'. As with yours, I have the 16k pumping air into the salon and forward berth. My 12k pumps air into the aft cabin and salon. On my boat, the aft cabin cools much quicker than the salon. I'm guessing the same is true for your boat. Anyway, if you do replace your 12 with a 16, I would think you need to somehow cut back the air going into the aft cabin and direct more to the salon, otherwise, the aft cabin will always be much cooler than the salon, maybe too cool. Just a thought.

Re: Swap out a 12K unit with a 16?

Posted: August 6th, 2019, 2:35 pm
by tonyiiiafl
Thank you. Very good point and you are spot on.

Re: Swap out a 12K unit with a 16?

Posted: August 6th, 2019, 11:26 pm
by km1125
If you're return air is pulling from the bilge then you're adding a lot of cooling load on the system. You really want to fix that.

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 3:12 am
by tonyiiiafl
I have looked at this many times and the blocking off of the bilge air looks like an impossible task. I may take this as a winter project, making a few modifications to reroute that air so it comes mainly from the room return vent. I HAD THOUGHT OF GETTING A PLASTIC BARREL OR TRASH CAN AND CUTTING A SECTION OUT, then placing it over the unit, and then running a duct to th return air vent. It is in design phase now. LOL

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 8:58 am
by bud37
tonyiiiafl wrote:Qr Bbpost I have looked at this many times and the blocking off of the bilge air looks like an impossible task. I may take this as a winter project, making a few modifications to reroute that air so it comes mainly from the room return vent. I HAD THOUGHT OF GETTING A PLASTIC BARREL OR TRASH CAN AND CUTTING A SECTION OUT, then placing it over the unit, and then running a duct to th return air vent. It is in design phase now. LOL



Now I have not seen your particular instal but........can you not just attach an insulated duct to the air inlet of the unit itself and run to a filter screen vent in the cabinet side or somewhere where it would just pull cabin air....that seems to be the way ours is.....just a thought.

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 10:15 am
by tonyiiiafl
That was my first thought, however, the routing under the aft bed is pretty funky. The air inlet is about 14” square, I need to figure out a way to attach the duct to it, then I may have to oval it out to get to the supply vent, which is a 10” x 14” cut out in the bottom of the aft bed. I am going to see if I can change positions of the unit to make it an easier task to route the duct.

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 10:56 am
by bud37
tonyiiiafl wrote:Qr Bbpost That was my first thought, however, the routing under the aft bed is pretty funky. The air inlet is about 14” square, I need to figure out a way to attach the duct to it, then I may have to oval it out to get to the supply vent, which is a 10” x 14” cut out in the bottom of the aft bed. I am going to see if I can change positions of the unit to make it an easier task to route the duct.


You just need some transitions.......people that do home furnace/air ductwork can make them so they flow correctly to go from your 14" square to whatever you need.....or at least tell you what sizes you need to make...

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 7:38 pm
by tonyiiiafl
Transitions would be hard pressed to get attached to the air intake of the condenser. That is why I thought of building a box around it with a removable cover. Then putting a transition on one side to pull the air in from the inside vent with a duct. Attached is a photo of the unit.
F326C0C8-D2F8-453E-9AEF-E0C733C0C652.jpeg

Re: Swap out a 12K unit with a 16?

Posted: August 7th, 2019, 9:37 pm
by bud37
Yup I see your problem....I think you could still do it, would just take a while to fab a box in front of the coil section....do they have a retrofit piece for your unit maybe??.......actually this is what I initially thought you may have got, one more like this.

40_59_dometic_ecd-digital-control_9108732755_54059_11.png