Best placement of fans inside main cabin?

[RichW9603]

Hi all,
I recently bought a 1989 Hunter 33.5. It does not (yet) have A/C installed and the boat is in Texas so it gets unbearably hot inside the cabin when there is no breeze blowing through. When there is a breeze, it is much more pleasant. So I bought a couple 12V Hella Turbo fans to help move air. My question is, is it better to place the fans in the forward corners of the cabin and have them blow aft, or place them in the aft corners and have them blow forward? I usually open the front hatch when on the water to help create a breeze, and what I want to avoid is having the fans cancel out the breeze.
Thanks for any ideas,
'Dubs

 

[odaydokay]

I say mount forward and blow aft to "go with the flow". When anchored or moored, remember boat tends to head up into the wind unless a current overcomes.....

 

[Justin_NSA]

FWIW. Ours are mounted at the beam. When we aren't actually below, we like to point them aft to exhaust the hot air. When hanging out down below it feels nice to point them where we are seated to get some air movement over us.

 

[Gunni]

Put them in a place which will help move your AC about the cabin once you install your duct outlets.

 

[Justin_NSA]

Put them in a place which will help move your AC about the cabin once you install your duct outlets.

One more reason our beam location works well. Our AC duct are on the V berth bulkhead. The fans are in the path of the cooled air.

 

[JohnVTX]

Point them toward your body when you are in cabin.

 

[whatfiero]

Put them in Windows to blow cool air in the cabin

 

[agprice22]

I put mine on the bulkheads near the edge, so they can hang in the passageways to blow air from the forward hatch rearward out the main companionway.

 

[Benny17441]

Your humidity does not seem too high at 48% so you may benefit from a portable evaporative cooler.

 

[BigEasy]

I installed four, one on salon forward bulkhead & one on aft salon bulkhead, one in V berth, and one in aft berth. Get that A/C installed asap! Don't let an installer talk you into a single outflow into the salon. When I had a 33.5 with a single A/C duct in the salon, it never adequately cooled the aft & V berths. Each compartment requires a dedicated A/C duct to adequately cool the entire boat. Keep cool; we still have 6-8 weeks of this record summer heat to deal with!

 

[Peggie Hall HeadMistress]

You'll want to pull air all the way through the boat from the cockpit and out the forward hatch. So I'd hang one from the overhead far enough forward of the companionway hatch not to bump your head on it coming down the ladder, and a second one from an overhead at the foot of the v-berth. 6" fans oscillating fans that you can swivel a bit should do the job. It did on my own 32' boat.

 

[Don S/V ILLusion]

Point them toward your body when you are in cabin.

It's amazing how complicated this seems to be

 

[RichW9603]

You'll want to pull air all the way through the boat from the cockpit and out the forward hatch. So I'd hang one from the overhead far enough forward of the companionway hatch not to bump your head on it coming down the ladder, and a second one from an overhead at the foot of the v-berth. 6" fans oscillating fans that you can swivel a bit should do the job. It did on my own 32' boat.

Hi everyone, thanks for the great input. And Peggie, I have heard wonderful things about you, you seem to be a wise sage on boat improvements.
Most folks seem to be saying that it is best to have the fans face aft, as apparently the breeze normally flows from fore to aft when the v-berth hatch is open. I need to test it but I think I remember that as well on the boat; I will go open the hatch next time I am there and see which way it flows. Mounting the fans in the aft corners of the cabin would seem to be the most out of the way, but I don't want them canceling out any natural draft.

'Dubs

 

[agprice22]

Don't overlook using a tent over the boat. We use a boom tent, and lowers the temperature in the cockpit and salon 10 degrees on a hot day. I know, I know... Upstate New York is not Tejas! But we get days in the 90's (well, a day, at 90, barely), and the boom tent works wonders especially when the breeze is blowing through the tent.

 

[Peggie Hall HeadMistress]

Most folks seem to be saying that it is best to have the fans face aft, as apparently the breeze normally flows from fore to aft when the v-berth hatch is open.

A good point. My YC had a mooring buoy field that a lot of us tied up to when we didn't want to mess with anchors. I usually single-handed when I only wanted to go to a buoy, so it was easier for me to catch a buoy from the cockpit and tie off on a stern cleat...which would put any breeze over the stern. And spmetimes the breeze would be over the sterns in a raft up.

So maybe the way to have it both ways is a fan with a mount that swivels enough to aim it either direction?

 

[justsomeguy]

So maybe the way to have it both ways is a fan with a mount that swivels enough to aim it either direction?

Brilliant!

 

[Chris Patterson]

I definitely keep one at the nav desk. That's where it seems I do the most sweating..

 

[MitchM]

we have 4 fans: 2 Caframo programmables (3 speed and 2 4 6 or 8 hour programs) that swivel to either blow into or out of the 2 cabins, 1 caframo 3 speed over the galley to exhaust cooking air through the port above, and one in the cockpit mounted high under the dodger drawing hot air out of the cabins. at anchor, we aim the fans to assist the breeze which ever way the wind is blowing from . the dodger fan is especially useful on hot airless days if the cockpit canvas has been wetted down.

 

[Ron20324]

Have a fan that blows whoever is in the galley. If you put them on the bulkhead to the vee, make sure you can sit on the bench and lean on the bulkhead without hitting the fan.

 

[RichW9603]

Hi everyone,
Went down to the boat today, opened the forward hatch and noticed that the wind seemed to be blowing from the companionway opening forward and out the forward hatch. The opposite of how I expected it to flow. Assuming it wasn't a fluke it makes sense from a fluid dynamics standpoint because pressure and velocity are inversely correlated, so since the air has to move faster out the smaller forward hatch than it comes in through the wide companionway opening, that speed creates a lower pressure and the pressure delta drives the flow. Basically a venturi. So I ended up installing the fans at the aft end of the main salon, one next to the dome light right above the nav station and the other right above and behind the galley. I was kind of surprised how little air the fans actually move, they only move around 200 CFM (not much compared to a 12V radiator fan which moves 10 times that much air), but it makes up for it on efficient energy consumption (and is pretty quiet). Those radiator fans are 6+ amps. I'll take the boat out and see how the airflow works under sail on the water, hopefully it will continue to vent aft to forward.
'Dubs