Solar Power Shed Project

[mwood]

3RRL - Sounds like you've got everything covered! I'm sure you'll enjoy this for years to come! Hopefully, a few years down he road, you'll look back and feel proud of all the hard work and planning you put into this to make it work just as planned!

 

[patrick_g]

Pat, need I remind you that the light bulb is a hardware issue and you should not be involved.

Guilty your honor but with an explanation. For a span of years prior to finding TRUE RELIGION (Software Engineering) I labored in service of false gods in tasks such as Electronic Hardware Design and consulting in same. I confess I designed medical electronic equipment that had no microprocessors nor any computational ability beyone simple analog (excuse me for using the "A" word) scaling. Deprivation was rampant, all math functions such as taking the log base 10 of the ratio of a reference current to a object current and displaying this on (oh goody) a digital display.

I have since successfully completed a 12 step program (5 times (recidivism is a *****) and only occasionally when with bad company do I do much design of analog circuits. I have honestly tried to quit and have managed to cut back a lot but getting this monkey off my back is not easy.

Pat

 

[Highbeam]

It would seem that if you have a sealed room and a sealed duct through which your engine fan is sucking outside air, that an open vent of the same size and located high in the room would exhaust the hot air at the same rate that it is being pulled into the room. It will get warm in there if you suck with the fan which is why I would recommend a pusher fan like on a bulldozer. Maybe cummins offers a pusher fan which would allow you to force air from the room through the radiator and out through the sealed duct with replacement air sucked in through (filtered) vents. Any vacuum that the room feels won't matter so long as all parts of the generator are exposed to the vacuum equally.

I wouldn't even worry too much about filtering the makup air since the genset was made to be operated outside.

 

[patrick_g]

Highbeam, Sorry, it just doesn't work that way. From your description,during a long run the room air would be all exhaust. Of course at equilibrium the same amount of heat would leave the bld as the engine produced but at equilibrium the inside temp of the room and the delicate electronics would get too close to the temp of the air coming off the hot radiator.

Reconsider the milk in the bottom of the glass example as it illustrates the exponential mixing problem very well.

A really good solution would be to use a reverse fan (pusher like you mention) and put a good fitting shroud/duct system to direct the hot air off the radiator out of the bld and not let it mix with the air in the bld. Then the fresh air coming in would dominate the interior temp.

Lowe's sells temp regulating vents for venting the crawl space of a house. Above a certain temp they are fully open. Below another temp they are fully closed. In between those tow temps they are intermediate. You could put a couple of those (were $9.00 each) or similar in the system and divert some of the warm air to the inside of the bld for winter heat but not to exceed a reeasonable temp.

If it were me I'd probably remote the radiator to a box on the wall and use a thermostatically controlled fan like so many cars use. By directing the hot air out fo the bld, fresh air would come in through the supplied vents. As to not needing filiters on the vents... They were not for the engine because as you say the engine and associated generator were designed for outside use. The vents are to reduce the ingress of excessive dirt and dust which will build up on the electronics. Filters are cheap and easier to change than to dust and clean the electronics.

Pat

Purposely filling the entire space, delicate electronics and all with the hot air off the radiator is not a good idea.

Pat

 

[RavensRoost]

3RRL (Rob):
I have been following this thread for sometime now and enjoy it. I guess I missed the post where it said your Onan PULLED air in the radiator vs. PUSHING is out. Is this for sure? I would have predicted it is a "pusher".

I have a weekend offgrid place and installed an 8KW diesel in an insulated "doghouse" (enclosure) on a slab inside a shed for noise treatment reasons as much as anything. Diesels aren't the quietest things around! The direction of airflow is in via fresh air louver to the generator end past the engine and OUT the radiator/2x louvers.

I ended up having to fab a shroud to duct radiator hot air to the louvers at side of shed. Later, I discovered the shroud itself was rejecting so much heat (in summer which is when it gets the most use: think A/C) that I had to insulate the shroud as well as add a large box fan in front of the air inlet louver to force as much of the heat out of the shed as I could (fan is wired/fused to genset outlet so it only runs when genset is running.)

RavensRoost

 

[RavensRoost]

Rob, I forgot to say box fan is blowing outside air into shed: pressurizing if you will.

RavensRoost

 

[patrick_g]

Bruce, If Rob's genset is a "PUSHER" we sure wasted a lot of internet bandwidth. If it is a pusher then duplicating your design would be a good alternative. Roger the insulation on the ductwork! The little fireplace/wood stove I had on my sailboat put as much or more heat into the boat via the stove pipe as from the stove itself. Likewise the wood stoves you make out of 55 gal drums by adding a cast iron door and flue pipe.

Pat

 

[Highbeam]

I would shy away from a non mechanical fan. There is something to be said for the dependability of a fan that pumps cooling air anytime the engine is running. Simple and reliable for a system that will run unattended.

Air must leave the room at the same rate at which it enters. Getting the hot air to leave is superior, as is pulling nonheated air over the engine and genset guts.

So does your fan suck or blow?

 

[patrick_g]

Highbeam, If it is a pusher it is a slam dunk. If not... well There sure are a lot of cars on the road with electric fans and a pretty low failure rate. I agree the pusher fan, engine driven, is a good thing but if it is not a pusher the hassle of trying to plug up the hot air leaks would probably f=drive me to a remote radiator and an electric fan. I suppose you could extend a mechanical shaft from the current fan mount to a bearing and a remote fan instead of an electric fan and retain the mechanical reliability. I agree on how nice it is that if the engine runs and needs cooling the fan turns for sure. It just matters what you would go through to avoid the small probability of an electric fan failure.

Pat

 

[3RRL]

3RRL (Rob):
I have been following this thread for sometime now and enjoy it. I guess I missed the post where it said your Onan PULLED air in the radiator vs. PUSHING is out. Is this for sure? I would have predicted it is a "pusher".

I have a weekend offgrid place and installed an 8KW diesel in an insulated "doghouse" (enclosure) on a slab inside a shed for noise treatment reasons as much as anything. Diesels aren't the quietest things around! The direction of airflow is in via fresh air louver to the generator end past the engine and OUT the radiator/2x louvers.

I ended up having to fab a shroud to duct radiator hot air to the louvers at side of shed. Later, I discovered the shroud itself was rejecting so much heat (in summer which is when it gets the most use: think A/C) that I had to insulate the shroud as well as add a large box fan in front of the air inlet louver to force as much of the heat out of the shed as I could (fan is wired/fused to genset outlet so it only runs when genset is running.)

RavensRoost

RavensRoost,
After reading the suggestions about having an exit for the radiator fan, I took it for granted that it was sucking air in, through the radiator from the outside. Much like a car or tractor radiator would.

I just looked at the schematic my solar contractor made and it is indeed a "pusher" as drawn. So the air is being exhausted through that opening. I have not been to my property for several weeks and have not seen the generator run myself, only from what the contractor told me. I am going up at New years and will confirm after the final walk through.

But for now, according to the schematic, consider it a pusher fan ... directly exhausting to the outside through that opening in the photo.

 

[RavensRoost]

RavensRoost,
After reading the suggestions about having an exit for the radiator fan, I took it for granted that it was sucking air in, through the radiator from the outside. Much like a car or tractor radiator would.

I just looked at the schematic my solar contractor made and it is indeed a "pusher" as drawn. So the air is being exhausted through that opening. I have not been to my property for several weeks and have not seen the generator run myself, only from what the contractor told me. I am going up at New years and will confirm after the final walk through.

But for now, according to the schematic, consider it a pusher fan ... directly exhausting to the outside through that opening in the photo.

Rob, then you are going to win on this one!

You may still have more heat in there than you would like when genset is running, especially summers, as the "doghouse" enclosure will radiate heat from the engine as not all of the heat will be pushed out through the radiator. (CUMMINGS, sorry about saying Onan, must have got Onan from Patrick's earlier post about air-colled Onan diesels in a military van.) See how it goes and take it from there. You may need to add a pressurizing fan and another exhaust louver independent of the generator to push remaining heat out, or other treatment.

Merry Christmas! (We get to spend Christmas through New Years at our "rancho" this year, and it might even be a white Christmas which is a treat for us!)

RavensRoost

 

[patrick_g]

Bruce in Prescott (Rhymes with biscuit), I concur. Rob lucked out. It is way easier to capture the effluent and vent it to the outside with a pusher. An electric fan with its supply air drawn in low on the north side of the bld and exhausted near the high point would sure help. You could power it directly from the genset in series with a thermostat so it will run only when the genset runs AND the temp setpoint is exceeded.

If any of the more delicate electronics are particularly close to the gen set you could consider a radiant barrier to "shadow" the electronics.

Pat

 

[Doc_Bob]

Bruce in Prescott (Rhymes with biscuit),
Pat

I always thought it rhymed with real hot.
Bob

 

[patrick_g]

Sorry Doc but one of the quickest ways to ID yourself as an unknowlegeable tourist is to say Press Scott instead of Prescut. It is pronounced flat with no emphasis on either sylable.

How do you pronounce Prague? (Prague in OK not Europe)
Eufala?
Miami in OK not in FL?
Pottawatomie? (Indian tribe, possibly of Viking origin and a county.

Prague has long A sound and only one sylable, not the ah sound for the European city.

You fall ah (sometimes yoiu fall uh) with the emphasis on fall.

Miami is My am uh

Pot ah what oh me

Regional dialects are fun, huh?

When in New York try to visit Lawn guy land.

In ND Minot rhymes with Why not? but the "why?" list is way shorter!

Pat

 

[Egon]

You bye's be needing a new thesaurus.

Newfie slang

 

[3RRL]

I found out that the generator radiator fan is definitely a "pusher", so all the hot air is being exited to the outside. The contractor put a thermometer in the shed to test how much it heats up with generator running for 1-½ hours. This was done in the after noon. The temperature only rose 2° after the test so this is good enough for to keep the instruments safe. This is a pretty reasonable test because we sized the system to reduce as much generator time as possible, so it may only kick on approximately 30 days out of the year, and for short periods only (we hope). During the Summer months, it may never need to come on except it's weekly self-exercise.

Here is a shot of the generator running, well ... of the power command screen anyway.

 

[3RRL]

We had our final walk through and were super pleased with the project. Our contractor really did a good job and we are very pleased.
The system is complete now and ready for the general contractor to use when he builds our home. There is 110v and 220v available to him. There is also water available from our well, so this will save us the cost of him having to bring up generators and truck water up while he's building. This is no small amount either, considering the year or more to build and fuel costs at a remote location.

I talked about the power vents on the battery side of the shed. There is one for each bank of batteries. They run constantly to remove any gasses, even though we have 96 of those miser battery caps that traps the vapors. Here is a shot of one of them.



This is a shot before everything was cleaned up around the shed, but shows the lights on and the two power vent exits near the top of each side. Our propane tank is filled and plumbed also. It has lines that run to the house, the barn/shop and the generator. It also has a "wet line" so I can fill up my small propane tanks such as for the bar-b-que and the lanterns at camp.



Our home will be located approximately 150' behind and to the right in that picture. It is a small plateau overlooking the entire valley.

 

[3RRL]

One last set of pictures of the Watsun 225 dual axis Trackers. Here they are "asleep" from the front and rear views. In the background of this first photo, you can see the view we will have from our home, except from a slightly higher elevation. The trackers are approximately 30' lower on an embankment below the homesite.





Also a couple more views to the South and to the East.





Thanks for looking.

 

[Defective]

Gee Rob...

Better have a chat with your contractor about his drinking habits. Looking at TrackerBackside.jpg, he's got everything tilted to the right.

 

[EddieWalker]

Rob,

Congratulations!!!!

Nice to see all that you've accomplished. It's been a very impressive project and you did a great job documenting it and explaining what you were doing and why. Both are very helpful in understanding something so foreign.

What's really amazing is just is just one step towards building your home!!!

Thank you,
Eddie