Reducing Salon A/C load and/or duty cycle

[Kquaine]

I am thinking of gutting my salon and adding insulation to the walls and ceiling to try and reduce the load on A/C system. Here in Texas we are already getting mid 90 degree temps. Hopefully with the addition of wall and ceiling insulation, cellular window shades, and a dehumidifier I will reduce the load on A/C unit. My questions are as follows:

1) Wall and ceiling insulation
a) Do I need to add a vapor barrier or something similar to be on either side of the insulation? Outdoor side or indoor side of the insulation? I am thinking that since the wood wall frame on the outside wall does not "breath" because the other side is covered with fiberglass that a vapor barrier is not needed. Any thoughts?

2) Dehumidifier
a) To help the salon "feel" cooler I am considering adding a dehumidifier or two. Is there a good way to automatically drain the dehumidifier units? I have seen some pictures of the salon walls opened up and there looks to be several pipes running from the fly bridge to somewhere below the salon. I am assuming running into the engine room somewhere. Does anyone know what these pipes are for? Drainage pipes to the bilge? Can I tap into the pipes to be used for drainage of my humidifier units?

I have a 1988 - 67' - CPMY

Thanks for any information or thoughts you may have!!

 

[SKYCHENEY]

Your AC units have hoses running from the condensation trays to a seachest below. Just tap into those.

 

[Pascal]

I really doubt messing with the walls and ceiling is going to make a difference. Mines are cool To the touch anyway thanks to the gap.

The biggest issues are the windows and doors, especially the windshield. Insulating these will
Make a huge difference but when on board you will loose the view. The salon on my 53, smaller but with a windshield instead of a bulkhead which you probably have on yours stays nice and cool all summer with two 16k BTU air handlers and no windshield covers. And we re also in 90s with 100+ heat index here.

I tried a GE dehumidifier in the crew lounge of the boat I run as it was always a bit humid despite the AC. It removes humidity but expels hot air making the room hotter. Most of them have a gravity drain option which usually doesn’t help unless there is floor drain. I had it rigged with a small condensate pump; you could use one to pump the condensate to an air con pan. I doubt it s goin to help

FUJIWARA Condensate Pump, Mini... https://www.amazon.com/dp/B07RVDTYN4?ref=ppx_pop_mob_ap_share

 

[Kquaine]

Your AC units have hoses running from the condensation trays to a seachest below. Just tap into those.

My salon A/C unit is of split design. My condenser unit is located in the generator room below the galley. The evaporator is located above my helm in the salon. My dehumidifier(s) would not be located near either unit.

 

[SKYCHENEY]

My salon A/C unit is of split design. My condenser unit is located in the generator room below the galley. The evaporator is located above my helm in the salon. My dehumidifier(s) would not be located near either unit.

Right. Under the evaporators are a condensate pan. That has the drain hose coming off of it. But if they are all mounted up high, maybe that won't work. Mine are at floor level.

 

[Kquaine]

I really doubt messing with the walls and ceiling is going to make a difference. Mines are cool To the touch anyway thanks to the gap.

The biggest issues are the windows and doors, especially the windshield. Insulating these will
Make a huge difference but when on board you will loose the view. The salon on my 53, smaller but with a windshield instead of a bulkhead which you probably have on yours stays nice and cool all summer with two 16k BTU air handlers and no windshield covers. And we re also in 90s with 100+ heat index here.

I tried a GE dehumidifier in the crew lounge of the boat I run as it was always a bit humid despite the AC. It removes humidity but expels hot air making the room hotter. Most of them have a gravity drain option which usually doesn’t help unless there is floor drain. I had it rigged with a small condensate pump; you could use one to pump the condensate to an air con pan. I doubt it s goin to help

FUJIWARA Condensate Pump, Mini... https://www.amazon.com/dp/B07RVDTYN4?ref=ppx_pop_mob_ap_share

Pascal - I did not think about the additional heat load the dehumidifiers would add. I will need to take that into consideration.

I agree the windows and windshield are a huge heat source. As far as the windows go I am looking at installing cellular blinds. This type of blind does a pretty good job of insulating the window. For the windshield I am currently using the mesh cover over the outside of the windshied. This helps reduce the solar load to the helm/salon but it also reduces the ability to go out for spontaneous trips die the cover being a pain in the butt to take of and put back on. I am looking at a way to add similar cellular shades to the windshield. Have them run up and down on track or some linear guide so the blinds follow the angle of the windshield. When a trip is desired I could just pull op the shades and go. Just an idea at the moment.

 

[rwaldrop13]

We used the RV windshield foil roll AGHITG Window Reflective Film Sun Blocking,Alumimum Bubble Foil Reflective Insulation for Keep Heat, 48Inch x10Ft Window Privacy Film (amazon.com)
It helped and was easily removed/replaced with help from painters tape. We were going to add this Heat Control Window Film, Window Tint Sun Blocking Blackout and UV Protection, one-Way Privacy Mirror Reflective Film,Explosion-Proof Premium PET Material,Comet Green,17.5 Inch x 6.5 Feet (amazon.com) as well but lost the boat to the hurricane. Our salon AC unit died completely and we decided to go with a big portable (14K BTU) from Lowes vented out one of the windows due to budget - we'd just installed 3 single-piece marine units in the lower cabins/galley. I never used the dehumidifier function (we set the unit in a pan just in case) but it did keep the salon fairly comfortable thru a SW Florida summer.

 

[Pascal]

The black mesh will get hot in the sun and transfer heat to the window.

Suction cups could be used to hold insulation material on the inside, easy to remove. Or snaps attached in the inside frames

On the 116 I run, in summer I used standard truck windshield covers to cut some of the heat in the RPH when a the dock. It helps the AC quite a bit even though I don’t even have the whole windshield covered :

 

[bostonhatteras]

The motor yachts of the 1920s or so, before the advent of Mr. Carriers invention applied to boats, would literally create their own shade over the boat. A canvas suspended on poles over cabin area, some vessels with canvas over the entire superstructure provided for shade which then caused the heat loading of the internal spaces to be far less. Sometimes less is more.

 

[Captain Ralph]

The motor yachts of the 1920s or so, before the advent of Mr. Carriers invention applied to boats, would literally create their own shade over the boat. A canvas suspended on poles over cabin area, some vessels with canvas over the entire superstructure provided for shade which then caused the heat loading of the internal spaces to be far less. Sometimes less is more.

The times we put a tent shaped tarp over our deck house down to the hand rails worked great. Like the old savannah trucks. Sun did not touch the windows or saloon roof. Just sucked taking them down to run the boat.

Blinds stop the sun rays from getting in, The heat stops on them or curtains.
Now those blinds or curtains are heat radiators into the area to be cooled.
IMO, all done there (blinds,curtains) is UV protection for the rest of the inside of the boat.

We tinted our salon windows, WOW, what an improvement over the (sun burned) curtains. Yes the glass gets hot but while moving or any moving air outside helps cool that glass down.
I am looking forward to try some kind of light colored external mesh to help even more over the windows. Maybe some spacers to keep it off the glass (pool noodles?).

We have been anchored out this weekend. Heading home tomorrow (bummer). Been hot, pretty cool inside.
I also have to ad, bilge ventilation and sealing the living space from the power and engine rooms is important also. Never was impressed with the Hatt power room ventilation scheme.

I remember my wife hosing down the coach roof with a water hose while living on the docks. She stopped when the steam stopped forming and the water stayed in place for a minute or so. Then real ice cold inside. I often thought of a dedicated RO, pump and lawn sprayer just to keep the coach roof wet.
The things we think up from the swamps.

 

[Sadey]

Ceramic tint on all of the glass, total game changer. We did all windows including the front pilot house windows. Darkest tint on the side widows and a very mild ceramic tint on the front glass.

 

[Captain Ralph]

Ceramic tint on all of the glass, total game changer. We did all windows including the front pilot house windows. Darkest tint on the side widows and a very mild ceramic tint on the front glass.

Ceramic tint ??
I got to look this up.
Thx

 

[cww]

The best improvement I made to my boat in that regard was tinting the windshield and salon windows with 3M Crystalline tint. It stays much cooler in the summer in there now, the difference is very noticeable.

 

[Beachcomber]

Added the 3M ceramics dark tint on all windows and very light on windshield. The difference was amazing.
https://www.3m.com/3M/en_US/p/d/b00016645/

 

[Captain Ralph]

It was a 3M shop that installed our tint a few years ago. I don't know if it was their Crystalline or not. When we get in I'll call and ask. We do like it and brag when I can.

Started reading on this ceramic window tint. WOW.
Next tint project, ceramic will be in the order.

Thx Sadey for your comment.
New product info comes into our swamp slowly.

 

[cww]

I really doubt messing with the walls and ceiling is going to make a difference. Mines are cool To the touch anyway thanks to the gap.

Same here. Whatever design Hatteras used to insulate the walls seems to be sufficient already. I live in Florida where it's boiling in summer, and the interior walls don't get warm to the touch they just stay whatever temperature the cabin is. I don't think that's the problem.

The only way I finally got it to where the a/c's were able to keep up in the dog days of summer was tinting the windows and windshield, that's a *lot* of solar load that gets cut out with a good ceramic film. Especially the windshield, the sun beats the dashboard in the sun and that acts like a big radiator that heats the salon up.

Also ceramics aren't like the old tint from 10+ years ago, you can still see outside when it's dark. The OP should start with that before messing with anything else.

 

[Sadey]

Any time Ralph. Still have your Datamarines. Just haven’t pulled the repeater out. Once I do I’ll send them your way.

 

[Pascal]

Another thing to consider on some of the MYs with AH up in the ceiling is to make sure the returns are well insulated with no hot air coming in. Same with the housing around the air handlers.

 

[Captain Ralph]

Any time Ralph. Still have your Datamarines. Just haven’t pulled the repeater out. Once I do I’ll send them your way.

In no hurry my friend.

 

[rwaldrop13]

The black mesh will get hot in the sun and transfer heat to the window.

Suction cups could be used to hold insulation material on the inside, easy to remove. Or snaps attached in the inside frames

On the 116 I run, in summer I used standard truck windshield covers to cut some of the heat in the RPH when a the dock. It helps the AC quite a bit even though I don’t even have the whole windshield covered :

Pascal we did similar strategy and it worked pretty well. The Admiral decided it worked well enough to carry the same cover-up thru the salon windows until I pointed out we couldn't see! One of our marina neighbors had an awning over the bow on poles, and "side curtains" hung from the overhang down the port and starboard sides made from sunshade material. I thought I still had a picture I took for reference, we were going to do the same. Blocking the sun from the windows with the gap made a huge difference in their interior and AC load.