Use of Bilge Blowers

[Sailor_Al]

Thanks everyone for the information. I may start using it; turn it when enabling the engine starter battery. Turning it off after shunting rhe engine down. Their really isn’t a down side. And after pulling into the slip, while on shore power, it would be nice if the blower could help the Air conditioning cool the cabin down.

I may try to measure the engine compartment temp.

[EmeraldCoastSailor]

I installed a $30 Shurflo blower to pull air out of the engine compartment. I have no concerns re diesel fumes. It is a little loud and draws about 3.5 amps but it is mostly used while running the engine so not a big deal. It makes a huge difference in keeping the boat from getting miserably hot in the FL heat. The ss clamshell that covers the exit on the stern gets quite hot to the touch which tells me it is working.

[GordMay]

Engineers refer to the difference between the ambient air (outside the boat), and the air in the engine compartment, as the delta T.
This difference should not exceed about 30 degrees Fahrenheit.

While considering airflow to the engine, you can use a basic test to check the sufficiency of the air inlets. At a fast cruise or at wide-open throttle, note the engine rpm, and then open an engine hatch and a cabin door.

If the rpm increases, along with the new additional flow of air, then you are not providing the engine with enough combustion air.

A common rule of thumb holds that decreasing air intake temperature by 10 degrees F will increase horsepower and torque by 1%.

More ➥ https://www.proboat.com/2015/06/venting-the-engineroom/

And ➥ https://www.marineairflow.com/blogs/...om-Temperature

[valhalla360]

Unless it's a very tight engine compartment, I wouldn't expect it to do much of anything while the engine is running. The engine is itself a high powered air pump pulling air from the engine room and sending it out with the exhaust. It's doing it in quantities far greater than the bilge blower is capable of.

If you are at dock or have excess battery capacity, running it for a bit after shutting down might help a little in terms of keeping the cabin from heating up due to the engine heat.

Propane should be properly bottom vented and diesel fuel doesn't create fumes like gasonline.