AC Window Unit

Gulf Comanche · Jul 18, 2016

Before I get started tearing out a window, I am looking for opinions on installing a window unit AC. I'm looking at a Fridgidaire 8000 btu AC with heater (heat pump & heat strip). There's a window on the backside of the pilot house that will fit this unit. My goal is to keep the pilot house/front cabin cool/warm. It also has dehumidifier. Not concerned about the galley head because of the stove there. 8000 btu is a little light, but I think it will work
What do y'all think? Thanks,
Mike

O C Diver · Jul 18, 2016

Don't think so, sorry. Part of the issue will be insulation or lack there of in a metal boat. Second, you have a lot of glass in the pilothouse, significant heat issue.

My 35' charter boat is air conditioned in the cabin and forward bunk area with 16,000 btu of AC. It's adequate and I'm in Maryland not Louisiana.

Ted

psneeld · Jul 18, 2016

Friend just put a 6000btu window shaker in his 33 Luhrs.

8000 is going to be light on hot days, but if it knocks most of the humidity out and you have a couple of fans to circulate the air...it should be liveable.

Realistically, with a hot engineroom...16K btu is just enough to kill the engine heat and gain from a lot of windows.

Heron · Jul 18, 2016

psneeld said:
8000 is going to be light on hot days, but if it knocks most of the humidity out and you have a couple of fans to circulate the air...it should be liveable.

Realistically, with a hot engineroom...16K btu is just enough to kill the engine heat and gain from a lot of windows.

Yeah.....Now that my boat is dark blue, I'm finding 12000 BTU's is marginal in this hot Carolina climate...I think a 16K upgrade is in the cards

DeniseO30 · Jul 18, 2016

Rule of thumb 4-500 sq ft of floor area per 12,000 btuh well insulated tight construction with solar shading it can go to 700 sq ft

psneeld · Jul 18, 2016

System Size Calculator

one of several marine air conditioner size calculators on the web.

My salon is about 14 by 10. I have a 16K unit and it is just about right.

The Calculator has it at 15.5K (a quick estimation).

Power boats generally seem to need a lot more BTUs per sq ft.

CPseudonym · Jul 18, 2016

psneeld said:
Power boats generally seem to need a lot more BTUs per sq ft.

Largely due to the square footage of windows present.

Pgitug · Jul 18, 2016

8000 will give you noticeable relief after the sun goes down. During the day you can shade the top of the ac unit with some potted plants.

psneeld · Jul 18, 2016

CPseudonym said:
Largely due to the square footage of windows present.

And air leaks to the outside, air leaks to the bilge, almost no insulation, small cubes for the amount of heat producers onboard, heat emanating up from warm water through the bilge, small cubes for body heat added, etc...etc...

Wonder how anything can cool one off....

janice142 · Jul 18, 2016

I have a 5k btu on the overhead of Seaweed's galley. During the daytime I put up window shades on the sunny side. Also, I close off the pilothouse with a mildew-proof shower curtain (the fabric variety) sold in Walmart for about $8.

Seaweed has lots of glass and is not airtight. There is zero insulation. In 90+ degrees the galley area is comfortable. I do pull back the shower curtain a couple of feet so the pilothouse does not get horrible.

Now I don't want Seaweed to look like a shanty-boat so I also bought and installed a Moby-Cool a/c cover. Here's a picture when we were putting it together.

Moby Cool makes them to the width you specify. Mine is exactly correct. And on the overhead the profile is low. I like it. Scott is the owner of Moby-Cool.com,barnacle antifouling,paint,a/c hood/hatch

Two things to consider:
#1) How are you going to power it?
#2) Can you cut off the air circulation to unused parts of the boat with fabric of some sort?

My shower curtain is white. It keeps the cold air in the galley area where I do most of my living. In the late afternoon I take down the shower curtain (using it below for the given purpose -- it's a boat, everything gets used twice!) and let the a/c cool the rest of the boat.

I did write a bit of an article (the full Moby-Cool part is still in my To-Do folder) ... that a/c story is here: Air Conditioning article on janice142

Good Luck. I tell you this much: Air conditioning makes life in Florida bearable during these months of 90+ degree weather. I cannot imagine life without it being on at least some of the time.

J, becoming the Queen of Decadence and loving it too!

Phil Fill · Jul 18, 2016

I installed 6000 btu units in each of the state rooms and a 8000btu in the salon that are enclosure and butted up against a port hole or window. We replaced the salon window with dark tinted glass, plex a glass covering the exterior, and heavy thermal curtains for the interior. My wife made a small quilt to close off the salon from the pilot house. The pilot house has a 8000 btu roof top. The port holes and windows were not changed modified.

kartracer · Jul 19, 2016

Mike
It is great to hear that you are putting A/C on the Comanche, I know it was a hard decision as to what and where to put one. I think you will enjoy all that cool air and you will never have to much A/C.

Deckape · Jul 19, 2016

Get the most BTUs that will fit the access . You may need it when the summer it at its hottest,or winter at its coldest.

Pack Mule · Jul 19, 2016

Hey GC ,
We have what I think is 8000 btu Dometic roof top air only no heat . It keeps wheel house nice and cold and the v berth very comfortable at night . It's ugly and kinda loud but it's old .I hate that it's on the roof . Probably going to replace next year with newer model of the same brand. I think the newer ones are not as loud . Check out my homeboy drain tube . It works and doesn't get clogged up .

Gulf Comanche · Jul 19, 2016

Thanks Ronnie, just couldn't bring myself to cut a hole in the roof like we talked about for the overhead AC. The answers I got to the question were about what I figured, 8000btu barely adequate. But, my pilothouse can be an oven mid-day, the front windows don't open so no breeze so the ac should help there.

Gulf Comanche · Jul 19, 2016

Pack Mule: I was in a discussion a while back w Kartracer, he was all for the roof mount, just couldn't do it.

folivier · Jul 19, 2016

Do you have floor space for a portable A/C?
That would make installation much easier. I recently bought an LG 12k refurb for $297 on ebay.

FF · Jul 19, 2016

The advantage of the RV units is heat rises , so the hottest air is conditioned.

Most are loud when the fan is on high , much quieter in a slower speed.

They all use the same mount so bigger , smaller , newer is just 1/2 a boat buck .

janice142 · Jul 19, 2016

O C Diver said:
Don't think so, sorry. Part of the issue will be insulation or lack there of in a metal boat. Second, you have a lot of glass in the pilothouse, significant heat issue.

I had not noticed the boat in question was steel. Oops.

Okay, you're probably not going to want to hear this BUT...

Our 40'er was steel too. We ended up removing the entire bow (top) and replacing it with fiberglass over wood. The interior of ours was like an oven. That change (it was unpleasant -- no doubt about that... dusty, rusty (chips of steel), dirty, icky and NOT FUN) and the end result was totally worth it.

Inside below (we had vee-berths, my cabin to port, galley to starboard, then head before coming up to the saloon)

Anyway, after the switch the interior was 10 degrees cooler.

Could you take down the height inside enough to add insulation? Even an inch of that blue (or pink) board would help. I have it on the inside of my hull where the green stripe is. The board has evened the temperature in my locker.

Also, shading the windows (the idea of Phil Fill's to use insulating fabric is Excellent) will definitely help. Can you add a bimini around the exterior of the pilothouse so the air cools before it hits your windows?

Lily Maria (a 44' Thompson) has a nifty set-up. Here's a picture:

Just aft of the bimini over the bow are blue ones that shade the side deck. I was inside and the boat was cool. The blue (sunbrella?) was see-thru. It's an amazing boat.

The full article (loads of pictures) is here: Janice142 article Life onboard Lily Maria (Thompson44 M/V)

Colin has some great ideas implemented -- ones I'm copying over for my Seaweed. He's a smart fellow. His Jean is a wonderful partner too. It's nice to see/meet happy couples boating.

Forgot one thing: I had one of those room a/c's that sit on the floor and vent outside. It did not do the job in 90+ degree weather. Too many windows, too many air leaks, no insulation. For me, for Seaweed the tall things that sit on the floor did no good.

I gave mine to a gal on a 30' Freedom. That's an older sailboat with LOTS OF INSULATION/good thick decks, etc. On her boat it worked fine.

healhustler · Jul 19, 2016

This piece of crap ole floor A/C is rated 9000 BTU (photo). It keeps my interior dry and at about 10 degrees cooler when the boat is shut up, sitting on the galley counter with the drain in the sink. In my 12 x 8 pilothouse, it doesn't do much better than 5 degrees in the sun. I've been over and over and over the options and after hearing very good ratings from other new Krogen buyers who have installed the 3M heat reflective clear film on their pilothouse windows, I decided to head to Home Depot and check out the display they have there. The display consists of a square box with a sample window of a different window film on three sides and a clear window on the remaining side. There is a heat lamp inside the box, and you can revolve the box around the heat lamp to test each window film including the 3M clear, a Limo tint, a clear window and one with a Metalic reflective film.

Even my Admiral agreed that the metalic window film was darned near as cool as the 3M stuff, so I saw that that there was a Gila display with the titanium film that is not an adhesive film, but a cling type. I just got the stuff today but I've been taking temperatures inside the pilothouse for the last couple of days. I figure I should get around to applying the film in the next couple of days and I'll post my findings here.

Capstan · Jul 20, 2016

Heron said:
Yeah.....Now that my boat is dark blue, I'm finding 12000 BTU's is marginal in this hot Carolina climate...I think a 16K upgrade is in the cards

There is also a product called "Temp Coat" on the "Silent Running" website. Hard to find it's right down near the bottom of the page. Anyway I have purchased but have not applied yet. It is supposedly very good at reducing heat transfer though the hull, deck etc. If you can get to these areas to apply it may be worth the money. It may save you quite a bit. I'm hoping with my smaller unit this will be enough for the Monkey.

Gulf Comanche · Jul 20, 2016

Larry: the portable AC won't work for me, still have to vent to outside and then the thing just stands there in the way, like R2D2 (Star Wars?). But, the titanium film you're trying sounds interesting, especially since it doesn't seem to have a sticky side. Looking forward to how it works out for you.

Star0210 · Jul 20, 2016

healhustler said:
This piece of crap ole floor A/C is rated 9000 BTU (photo). It keeps my interior dry and at about 10 degrees cooler when the boat is shut up, sitting on the galley counter with the drain in the sink. In my 12 x 8 pilothouse, it doesn't do much better than 5 degrees in the sun. I've been over and over and over the options and after hearing very good ratings from other new Krogen buyers who have installed the 3M heat reflective clear film on their pilothouse windows, I decided to head to Home Depot and check out the display they have there. The display consists of a square box with a sample window of a different window film on three sides and a clear window on the remaining side. There is a heat lamp inside the box, and you can revolve the box around the heat lamp to test each window film including the 3M clear, a Limo tint, a clear window and one with a Metalic reflective film.

Even my Admiral agreed that the metalic window film was darned near as cool as the 3M stuff, so I saw that that there was a Gila display with the titanium film that is not an adhesive film, but a cling type. I just got the stuff today but I've been taking temperatures inside the pilothouse for the last couple of days. I figure I should get around to applying the film in the next couple of days and I'll post my findings here.

We didn't get the cling stuff but we bought the Gila metallic that claims to have a pretty high heat rejection rate. We scraped all the old tint off the windows and put the new stuff on a few. It's every bit as hot to the touch as the bare glass. It's also weird because it's metallic on the inside particularly at night and it's like looking in mirrors all the time. You can't see out at night very well but you can see inside from the outside very well. It's like it's backwards. I asked hubby if he thought they goofed up and put the adhesive on the wrong side!

As an experiment, we put it on the outside of one of the Windows and that actually works much better. To the touch, the glass is much cooler and you can't see in at night but can see out just fine.
We're seriously thinking about just putting it on the outside. It's cheap enough and easy enough to replace every few years if it gets messed up.

I just don't know if I'm a fan at all of the mirrored look. But I'll live with it if it reduces the heat.

bayview · Jul 20, 2016

I wonder if anyone has tried one of those two part ACs. No window is required and just a smallish hole for piping and power.

Cottontop · Jul 20, 2016

bayview said:
I wonder if anyone has tried one of those two part ACs. No window is required and just a smallish hole for piping and power.

I have asked about the mini split systems in another thread but there doesn't seem to be much experience with them.

They look easy to install and not expensive.

Carolena · Jul 20, 2016

From Janice :"Forgot one thing: I had one of those room a/c's that sit on the floor and vent outside. It did not do the job in 90+ degree weather. Too many windows, too many air leaks, no insulation. For me, for Seaweed the tall things that sit on the floor did no good."

We also tried one of these floor units in our sailboat. It would bring the humidity down a bit and seemed to cool about 10 degrees lower than outside temps at night. It couldn't keep up at all during the day. The big problem is they vent outside and the air has to be returned to the cabin somehow. Basically, as you cool and dry the air in the boat, the vented air is constantly being replaced with hot, humid air through leaks from outside, so it isn't very efficient. We eventaully installed a true marine unit and never looked back.

kartracer · Jul 20, 2016

I had a company that does most of the offshore supply boats and high dollar sportfish in the area come on board and do the windows. He said this stuff would drop temp by 10 degrees at the window, he was right close. Not cheap but works.

Star0210 · Jul 20, 2016

kartracer said:
I had a company that does most of the offshore supply boats and high dollar sportfish in the area come on board and do the windows. He said this stuff would drop temp by 10 degrees at the window, he was right close. Not cheap but works.

What did he use?

kartracer · Jul 20, 2016

Getting ready for a long weekend on LunaSea, will look it up when on the boat.

Star0210 · Jul 21, 2016

kartracer said:
Getting ready for a long weekend on LunaSea, will look it up when on the boat.

How fun!
Where are you headed?

AC Window Unit

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