Routing blower for venting from engine compartment

[smokey73]

For you Hunter 40.5 owners.
I'd like to run a bilge blower (12V) to exhaust heat from the engine compartment, especially after the engine has been shut down and I'm trying to cool the cabin after a hot day. If you have such a blower how did you route the 3 inch flex line from the engine compartment and where did you exhaust the air? Pictures would be helpful.

Thanks in advance.

 

[Dan_Y]

When you figure out how to route it, consider using two, one to exhaust hot air and one blowing in cool "make up" air. I did this on our '91 h30. The exhaust hose opening was mounted high in the rear of engine compartment and the make up air came in by the tranny and under the oil pan to the front of the compartment. I was trying to help cool the alternator. I typically run the blower when the engine is on and after returning to the dock for a while. Those inline rascals are loud. BTW, the side wall of the walk through transom is a good place for the vents. I put them there on our 30 and the vent is there from the factory on our 36 as well. Dan

 

[Rich Stidger]

Dan- I have done this. I was cooling my alternator. I ran the 3" hose from under the alternator along the side of the compartment, thru the stuffing box area, under the aft berth edge and under the aft berth. I located the in-line blower under the berth and routed the exit hose to the port vent opening for the aft cabin. I used that existing vent for the engine compartment and plugged the vent for the aft cabin. I have a marginal internet connection now, but I will send all of my pictures asap.

 

[BayMan]

I typically run the blower when the engine is on and after returning to the dock for a while.

I was reading my owners manual (H450) the other day and noted that it says I should run the blower when the engine is running. It sounds like that is your practice. That's new to me. Do others do that also?

 

[Ron20324]

I was reading my owners manual (H450) the other day and noted that it says I should run the blower when the engine is running.

I would be surprised if there were any boats that DID NOT have the blower wired so it ran when the engine did.

 

[smokey73]

Thanks Rich, That is the route I was thinking except to route to the Stbd vent opening since my generator is in the port lazarette. Where did you run the power from? I have an spare 12 breaker on the panel so I thought I'd run it from there. By the way, how is the new boom furler working out? Any luck on finding a way out of the frigid north before the winter? I'm looking forward to the pictures to give me a head start based on your experience.

 

[JamesG161]

I ran the 3" hose from under the alternator along the side of the compartment, thru the stuffing box area, under the aft berth edge and under the aft berth.

Good idea!
In addition....
You don't need a big hose to move heat if you do this..

consider using two, one to exhaust hot air and one blowing in cool "make up" air.

You could use a ≈1" hose and put more than just a "fan" but a little higher pressure blower that forces the heated air out. The suction side would draw air in from cabin or the second hose that just enters in the best spot near your engine.
Thus circulating, picking up heat and blowing it out.
Jim...

 

[danstanford]

For you Hunter 40.5 owners.
I'd like to run a bilge blower (12V) to exhaust heat from the engine compartment, especially after the engine has been shut down and I'm trying to cool the cabin after a hot day. If you have such a blower how did you route the 3 inch flex line from the engine compartment and where did you exhaust the air? Pictures would be helpful.

Thanks in advance.

I am just replacing mine as some PO had busted the louvers out of the outlet and punched a hole in the side of the hose to run the BBQ hose into the gas locker. I assume my set-up was factory and it is 4" flex-hose. The hose has been run down behind the engine, along the center line beside the muffler, up behind the panel at the aft end of the aft berth, over to the port side up to under the cockpit coaming where there is an opening into the port aft locker then out the stern with a 4" vent. It does not come on when the engine is run but does have a dedicated switch on the main panel.
Dan

 

[Dan_Y]

As a point worth noting, and in troubleshooting a blower that won't run, when Hunter added the automatic fire extinguisher to the engine compartment and the indicator panel at the engine panel, the blower power is actually run through a relay the cuts blower power if the fire extinguisher discharges. A switch in the extinguisher head closes (or opens...I forget which) to signal the control panel to sound the alarm and switch the blower relay off.

 

[Rich Stidger]

Dan,

Here are the pictures I promised....
I don't remember where I tapped into 12V power, but the blower runs continuously with the engine.

 

[JamesG161]

As always Rich, dang nice job! But you forgot one thing...

A tee to use as a hair blow dryer and winter heating!

Jim...

 

[smokey73]

Thanks Rich, That is exactly what I needed and pretty much what I had planned. Boy is that engine clean!!! Are you sure you ever run it? Don't know what I was thinking, my generator is in my stbd lazarette so I'll be running the duct work to the same outlet as you. Thanks again!!! Experience of others really cuts down on the learning curve.

Dan

 

[Rich Stidger]

Dan,

I did use a 4" hole cutter to cut a hole in the center compartment under the aft bunk for the hose and I think I remember also cutting another hole near the edge of the floor in the port side aft lazarette for the hose to come through. I used a 3" hose, but a 3 1/2" or 4" hole is much easier to get the duct through.

 

[smokey73]

Dan,

I did use a 4" hole cutter to cut a hole in the center compartment under the aft bunk for the hose and I think I remember also cutting another hole near the edge of the floor in the port side aft lazarette for the hose to come through. I used a 3" hose, but a 3 1/2" or 4" hole is much easier to get the duct through.

Thanks for the tip. I have a 4" hole saw so that seems to be the way to go. I hope to get this installed in a few weeks when I can tolerate being down below for awhile. Maybe I can go over to the yacht club dock and hook up to electricity for the night and cool the boat down before I work. It will sure make the job easier with the 50 plus day run of over 90 degrees each day. Don't even need a water heater to take a shower on the boat, the water tank temp is warm from the boat setting in the sun.

 

[Dan_Y]

Nice install Rich. Does the vent below the alternator blow air in or pull air put?

 

[Rich Stidger]

Pulls the air out. The vent is on the air output side of the alternator. The Balmar has two internal fans that pull from the rear and push out the front where my vent hose is located.

 

[All U Get]

I redid our plastic hose with the aluminum duct thinking it would last longer and I wouldn't need to squeeze into that small hole ever again. Yeah just kick me when I think that way again.

All U Get