Should fan for generator radiator blow out or suck in?

[belfert]

Justin from Wrico recommends that air blows out through the radiator rather than sucking in through the radiator.  In my case, that could mean trying to blow air out the side of the bus.  Will I run into issues with air blowing out the side of the bus while driving down the road?

My previous generator had a factory enclosure similar to an Onan Quiet Diesel.  It sucked air in through the radiator which didn't seem to cause any issues.  The air was pulled in from the side of the bus and exhausted out the bottom.

[Utahclaimjumper]

 Two things come to mind,,air pulled in from the side will also do well cooling the engine after being pulled thru the radiator,, air pulled from the bottom off hot asphalt is hotter than it would be from the side at three feet off the pavement..>>>Dan

[richard5933]

Mine pulls air from the driver's side of the bus, through the radiator, across the gen head/engine, and then out through the floor of the bay by way of the large squirrel fan.

[buswarrior]

What is cooling the electric generating bits? At full pop, there's a lot of heat... fresh air or heated radiator air?

Cooking the head gets expensive in a hurry.

Controlling the uncontrolled... Suction on the enclosure controls where exhaust leaks go, out the rad. Blowing into the enclosure pressurizes it and then every seam and crack is a potential CO problem.

Happy coaching!
Buswarrior

[luvrbus]

All the large (750KW) commercial generators that are enclosed blow through the radiator that I work on   

[belfert]

What is cooling the electric generating bits? At full pop, there's a lot of heat... fresh air or heated radiator air?

This question is just about the radiator which is planned to be external of the radiator enclosure.

[luvrbus]

My remote mount radiator on my Eagle blew through the radiator ,my 12500 Onan with the radiator laying flat blows through the radiator and creates a lot of dust in some parking lots  ? is do want the dust sucking in or blowing out     

[tr206]

My generator blows out the radiator and yes the air flow out going down the road stops so my generator would shut down (over heat) it would run for hours when your not moving. So I put a 14" Hayden electric radiator fan with a thermostat on the grill to push the air out it has worked great ever sense. in regards to air intake from the bottom of the bus I put a weatherproof air filter kind of like a furnace filter and yes its washable.

[DoubleEagle]

I have four different generator setups, and the only one that gave me trouble was the remote radiator one that had the intake in the center of the front baggage bay. It would cool fine sitting still, but going down the road it was in a low pressure area and the engine would get hotter. The entertainer Eagles have a grille on the side vertical wall, and the exhaust on the other side of the coach. Whenever there are intakes or exhausts on the underbelly, dust clouds will form outside or everything inside gets dirty quick, if you go on dirt roads. A filter might help temporarily, but not long term.

It seems logical that if the air flows past the engine and then past the radiator to the outside that the most heat would be taken away, but the air flow volume has to handle the generator, the engine, and the radiator. The remote radiators can handle the heat with the correct size, but then you might need a second fan to move air from the generator compartment. Two different sizes of squirrel cage fans is what Martin Diesel recommended for their setup (the bigger one was for the radiator), but I think both fans should have been bigger, and had variable speeds.

[chessie4905]

where the exhausted air comes out, so does noise. Coming out the bottom, the ground absorbs most or all. Dust? Lay down apiece of mud flap or wet ground. If it comes out the side, which side? Drivers side, could blow dust, heat, possibly diesel and fuel odor towards close by campers.Pass side, could blow where you sit and lounge. Just things to ponder. Personally, I prefer ground blow. Both my coaches are set up that way. But whatever works for you is best.

[richard5933]

Like every other system on a bus conversion, in the end it's going to be a compromise. If you try and incorporate every suggestion made to cover all the possible situations it will never get done.

A good starting point is the physical layout of your particular install. I think that far more important to generator/engine cooling is air flow rather than the direction it's going. And, if you plan it correctly you can use the motion of the bus to increase air flow rather than have to fight it.

[belfert]

Wrico sold me two squirrel cage blowers.  One large one for the radiator, and a second smaller one for cooling the generator compartment.

I will probably suck the air in from the side and exhaust it out the bottom.  That is basically the same way my previous generator worked and no cooling issues going down the road.

[silversport]

My air intake I did two, one that goes directly to the head of the generator, the second to the box itself. the radiator exits between the front wheels. Installed two fans, one on the box intake side (relieve negative air pressure) and the big boy on the radiator. Works going down the road & no dust when stationary.

[DoubleEagle]

where the exhausted air comes out, so does noise. Coming out the bottom, the ground absorbs most or all. Dust? Lay down apiece of mud flap or wet ground. If it comes out the side, which side? Drivers side, could blow dust, heat, possibly diesel and fuel odor towards close by campers.Pass side, could blow where you sit and lounge. Just things to ponder. Personally, I prefer ground blow. Both my coaches are set up that way. But whatever works for you is best.

The dust problems I have had are when going over dry dirt roads and lots, or fairground grassy areas that have been pulverized and are like talcum powder. Big clouds of dust get stirred up easily, even the tires throw some dust while moving.

While parked it is possible to put something on the ground, but it might need to be bigger than a mud flap, and wetting might work for a little while. I think the best overall solution is a side wall intake high enough above the ground, and rooftop exhaust. The problem is finding the space inside for that exhaust chimney, but it could be combined with the exhaust piping. Keeping both the exhaust cooling air and the engine exhaust in a long run up to the roof might make it easier to muffle the noise as well. Maybe the waste tank vent pipe could included also. One passage-way for everything you want to get rid of quietly without offending the neighbors.

[belfert]

My air intake I did two, one that goes directly to the head of the generator, the second to the box itself. the radiator exits between the front wheels. Installed two fans, one on the box intake side (relieve negative air pressure) and the big boy on the radiator. Works going down the road & no dust when stationary.

That looks like a great setup, but you must have an entire bay from one side to the other for your generator.  I am sure it is quiet with all the foam and baffling.  I wish I had the space to do something similar.  I am a bit confused about how you duct the exhaust air between the wheels.  How do you get the air down below the sides of the bus?

My Dina is 43 feet long, but has less luggage bay space than most 40 foot coaches.  The wheelbase is very short so they had to sacrifice bay space.  There are two full width bays about 50" wide and a third bay that is about 36" wide.  One of the wide bays has 1/3 of the bay partitioned off for the A/C condensers and I used that space for the generator.