Hi Jim-
I wanted to comment on the generator noise reduction article by Jerry. An easy and relatively inexpensive solution that gives dramatic noise reduction for portable generators: Rubbermaid-type plastic storage sheds. These sheds typically have about a 5′ wide x 2.5′ deep footprint, a composite floor, and are an ideal size for a typical, 2,000 to 7,500 watt generators.
To modify the plastic shed for running the generator inside, four important, simple modifications are needed: 1) Cutting a small intake port on one side, and covering it with any type of breathable, mesh screen, to keep critters out. 2) Cutting a 3″ or 4″ round exhaust port on the opposite side from the intake. 3) Mounting a marine/bilge type 12 VDC exhaust blower motor to the exhaust port and wiring it to the 12 VDC circuit of the generator. 4) Placing an aluminum-faced fiberglass HVAC insulation panel where the generator’s exhaust will most closely hit the plastic interior wall of the
shed. The exhaust is hot enough to melt the plastic without the insulation.
My setup has two 4″ Rule brand marine bilge blowers wired in parallel, plugged into the 12 volt panel outlet of my Generac portable generator. When the generator is started, the blowers start. I have taken temperature measurements inside the enclosure with the generator running, and it only varies a few degrees from the ambient air temperature. The blowers exhaust a tremendous volume of air; heat doesn’t build up inside the enclosure because the air turns over so quickly.
The sound reduction is tremendous. The generator becomes a distant background noise at about 50′. Much more than that, and it becomes nearly
inaudible.
Cutting a hole in the composite floor for some type of security fixture to lock the generator to is also an easy project.
Hope this is useful. Regards, – Rich S.