Category Archives: offgrid

Direct vent furnace thermostat replacement

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Recently I’ve had some challenges with stability on the low voltage thermostat that controls my 30000 BTU Williams direct vent furnace which I rely on to keep the cabin above freezing when I’m not here. Here’s the faulty one:

On several occasions I’ve woken up to temperatures of 50° where the thermostat failed to kick back on, so therefore I’m looking into replacement options. Grabbed 3 potential models to use from Home Depot, each with their own pros and cons and will decide which one is best for this application.

The first two units that require no external power source one being the “dumbest” which is a manually controlled unit, the second one being a little less dumb with a basic set of programs on a 7 days schedule that runs off a 2 AAA batteries. the semi smart one is a wireless thermostat that requires what’s called a “c wire”, and for my application requires a special power adapter that plugs into a 110 outlet in the adapter puts out 24 volt AC current. This is what the “semi-smart” thermostat needs to properly power it’s wireless other smart functions. Here’s the C wire adapter I ordered from Amazon:

This introduces more complexity in the heating system and adds an additional potential single point of failure, but I gain the additional benefit of being able to remote control and monitor the unit from afar.

Right now I’ll be testing out “semi-dumb” thermostat. It runs off 2 AAA batteries. That’s the advantage. Simple easy, virtually fail-safe.

Trade-offs…

Remote control vs potential for power failure.

Will see what model wins out in the end…

Rewiring the 12v system in the cabin

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About to tear down and rewire my entire 12v wiring, lighting, and appliances in the cabin. Making it safer and easier to access instead of having it right above the tankless hot water and pressure tank.

Bigger isnt always better

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I’ve been wanting to test out this 12v brushless fan for a couple different potential uses. These are normally used to cool high end PC gaming machines.

There are plenty of fans this size with higher RPM, but they consume a more power. I chose this one because it’s 3 watts and only draws 0.4 amps, while still providing sufficient RPM for my us cases.

I’m planning to use these to help circulate air in the crawlspace, near the woodstove, and in the loft. I’ve had it running all night and makes a HUGE difference in how the cabin is heated, even though I still have a lot of insulation and finish work to complete inside.

I am also going to install one of these in the exhaust area for my DC propane fridge to prevent it from overheating.

Efficient power generation for the dark days of winter

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Most everyone living offgrid relies on some sort of generator as a mission critical power generating device. I’ve purchased 2 generators and am using neither of them.

The 5500 watt Generac is a propane powered unit with several glaring design flaws. It’s damn near impossible to start in cold or warm weather and sucks down propane. It has less than 60 hours on it. I’ll sell it for half what I paid or best offer at this point.

The Honda EU2000 gas powered generator worked fine all summer but then stopped putting out AC power. I’ve done a fair amount of troubleshooting and think it’s the inverter board. I’m certain excessive moondust is to blame.

So here I am getting by perfectly with the custom 6.5 hp/212cc motor/alternator setup. Still blows me away every time I fire it up.

This is all I need to charge my batteries and power everything needed in the cabin. 3/4 gallon gas lasts 10-11 hours and will leave batteries fully topped off even during times of heavy use. That’s pretty damn impressive.

This includes my well pump and all 110v AC and DC appliances. Oh also — It only cost about $300 for all the parts. Compared to $800 for the General and $800 for the Honda.

Have a a smaller 3hp engine on order that a buddy is gonna setup. See if we can fine tune and run even more efficiently.