jim rosenthal
04-26-2003, 04:29 PM
Someone, I can't recall who, asked me to post a few details of this device, as other folks might want to build one. Total cost was less than $100.
I found that when I ran my boat in warm weather, after shutting the engines down, a lot of heat remained in the engine room. Since heat rises, the salon ended up hot as well, requiring running the AC. Also, letting the engine room bake in residual waste heat didn't seem good for the hoses, genset battery, pumps, etc. I decided to install an engine room ventilator.
I used a 110vac squirrel-cage fan that I bought from Allen Machine or Grobans in Boats&Harbors. I mounted it on a board, with a circular cutout for the fan to draw air. A local HVAC shop attached a flange for a hose. The hose, which is six inches wide, goes to one of the side ventilator openings; in my boat these hoses come from the top of the vent and are draped over and run to holes in the deck, through which they dangle into the engine room at the side of the boat. I painted the whole assembly before I installed it, since it is ordinary steel and would rust if not coated.
I installed a timer (one hour, Intermatic, Home Depot), and ran the 110vac cable to a spare breaker on the Hatteras electrical panel. When the boat is out running, and the fan is off, air is free to come into the engine room through the hose and fan cage, it does not seem to block it. When I shut the boat off, I set the timer for an hour. The amount of hot air that is exhausted out the side of the boat is impressive. After an hour it is noticeably cooler. Although the fan is next to one of the engines, it seems to draw air across the whole engine room. Interestingly, it does not seem to draw air more from the same side of the boat; the whole engine room cools down. The installation is so cheap and simple that you could install one on each side of the boat, actually. The motor draws very little current when running- it does not even register on the wattage scale of the shore panel. It is audible, but not loud, and not annoying.
Bigger Hatteras yachts than mine had thermostatically controlled engine room blowers, and fans. This is not as good an installation as the factory did, obviously, but it is simpler and seems to do the job. The salon stays cooler, and the engine room likewise.
I found that when I ran my boat in warm weather, after shutting the engines down, a lot of heat remained in the engine room. Since heat rises, the salon ended up hot as well, requiring running the AC. Also, letting the engine room bake in residual waste heat didn't seem good for the hoses, genset battery, pumps, etc. I decided to install an engine room ventilator.
I used a 110vac squirrel-cage fan that I bought from Allen Machine or Grobans in Boats&Harbors. I mounted it on a board, with a circular cutout for the fan to draw air. A local HVAC shop attached a flange for a hose. The hose, which is six inches wide, goes to one of the side ventilator openings; in my boat these hoses come from the top of the vent and are draped over and run to holes in the deck, through which they dangle into the engine room at the side of the boat. I painted the whole assembly before I installed it, since it is ordinary steel and would rust if not coated.
I installed a timer (one hour, Intermatic, Home Depot), and ran the 110vac cable to a spare breaker on the Hatteras electrical panel. When the boat is out running, and the fan is off, air is free to come into the engine room through the hose and fan cage, it does not seem to block it. When I shut the boat off, I set the timer for an hour. The amount of hot air that is exhausted out the side of the boat is impressive. After an hour it is noticeably cooler. Although the fan is next to one of the engines, it seems to draw air across the whole engine room. Interestingly, it does not seem to draw air more from the same side of the boat; the whole engine room cools down. The installation is so cheap and simple that you could install one on each side of the boat, actually. The motor draws very little current when running- it does not even register on the wattage scale of the shore panel. It is audible, but not loud, and not annoying.
Bigger Hatteras yachts than mine had thermostatically controlled engine room blowers, and fans. This is not as good an installation as the factory did, obviously, but it is simpler and seems to do the job. The salon stays cooler, and the engine room likewise.