DC-Living, all DC appliances for new Tinyhouse -Offgrid project?

[Checkthisout]

Right you are. But I still try to figure out why I am wrong ? The author Motsenbocker in his 120vdc mancave.

No. 120V a/c or whatever is normal in your country.

I have a blended system that uses a/c and d/c and it just isn't worth it for the reasosn listed.

You gain nothing but have to install extra wires for the dc side, another fuse panel, use larger wiring and things like pumps fluctuate quite a bit in output say between 14.4 volts and 12.5 volts.

Wire it like its a house and then "plug it in" to your solar system and be done and be done with it.

You

 

[Tomthumb62]

true, they are more expensive, but so far my research suggests it's actually not that much.

In our case the price difference was dramatic. Similar sized 12v DC fridge sold for $1500 and we got a 120v fridge for $250 (Amazon scratch and dent special but the scratch isn’t visible in our installation) and a super efficient Victron inverter powers that and everything else, which are low draw like charging phones/tablets/laptops. The inverter cost $292, so the “fridge” costs us $567 and we have an inverter for everything else. No microwave though and propane cooks and heats. 400W keeps it running happy except when Tue temps and humidity get high enough (ie, 95F, 80%RH), then we run the generator for a short bit or drive to a place to plug in. The only real upside of the DC fridge is it’s 9% more efficient and at $1500 it wasn’t worth it. Plus we needed a small inverter anyways. Fortunately where we live and travel those kinds of summer conditions are short lived. We don’t even have an air conditioner in our trailer, but we do at home (on grid). Our home A/C typically runs for 10-40 days per year and I set it at 80F. Fans take the edge off in the trailer and we find creative ways to cool off like people used to do before A/C. I hate A/C and would probably turn suicidal or at least antisocial if I ever were to move to someplace like Phoenix in the summer, lol.

What size fridges and prices were you seeing when comparing AC to DC?

Instead of a microwave, we use a steamer. Just a basic steamer basket on a lidded cookpot. Does most of what we used to use a microwave for and uses very little energy and is idiot proof. Microwaves running off DC can lead to lots of little gremlins. But I realize that some people covet their microwave like I do a wood stove, so maybe that’s just not an option for you right now, lol!

 

[Tomthumb62]

No. 120V a/c or whatever is normal in your country.

I have a blended system that uses a/c and d/c and it just isn't worth it for the reasosn listed.

You gain nothing but have to install extra wires for the dc side

I know you know this but this can confuse the heck out of newbies:

AC or ac = “alternating current”
A/C or a/c = “air conditioning”

DC or dc = “direct current”
D/C or d/c = I don’t know this one

It may be that different parts of the world use different abbreviations. But since this is a forum based in the USA, I think one of the electricians here suggested we all use the same ones so as not to lead to confusion. This electrical and solar stuff is confusing enough if you’re a beginner!

 

[eXodus]

Just go 120V for everything.

You may one day decide that 48Volts DC is better an then all your 12volt stuff has to go a voltage reducer which causes the same losses as the inverter.

Not sure, the 48V and 12V DC appliances are more efficient then some native 120V AC stuff. So yes the converter 48v - 12V might have the same 96% efficiency a inverter has. But the end device is still better.

Less components on DC, no permits, no inspections, no single point of failure.(multiple parallel batteries - directly feeding devices)

120V Electric installation changes the definition of a building.

With DC only property is still a camp, vs a dwelling, lower /no insurance, lower taxes etc.

You gain nothing but have to install extra wires for the dc side, another fuse panel, use larger wiring and things like pumps fluctuate quite a bit in output say between 14.4 volts and 12.5 volts.

Pump output really doesn't matter in house setup with pressure tanks. I don't care if the pump runs 5 or 10 minutes to fill up the Tank every hour.

What size fridges and prices were you seeing when comparing AC to DC?

10 Cubic, first page table - all listed.

 

[Checkthisout]

I know you know this but this can confuse the heck out of newbies:

AC or ac = “alternating current”
A/C or a/c = “air conditioning”

DC or dc = “direct current”
D/C or d/c = I don’t know this one

It may be that different parts of the world use different abbreviations. But since this is a forum based in the USA, I think one of the electricians here suggested we all use the same ones so as not to lead to confusion. This electrical and solar stuff is confusing enough if you’re a beginner!

Didn't think of

Not sure, the 48V and 12V DC appliances are more efficient then some native 120V AC stuff. So yes the converter 48v - 12V might have the same 96% efficiency a inverter has. But the end device is still better.

Less components on DC, no permits, no inspections, no single point of failure.(multiple parallel batteries - directly feeding devices)

120V Electric installation changes the definition of a building.

With DC only property is still a camp, vs a dwelling, lower /no insurance, lower taxes etc.

Pump output really doesn't matter in house setup with pressure tanks. I don't care if the pump runs 5 or 10 minutes to fill up the Tank every hour.


10 Cubic, first page table - all listed.

Well, I would like to see the benefits penciled out.

 

[tmbiv56]

do you have some of those plans or final product to share? Would love to learn from someone who already went through the experience. I'm still in the planning stages and want to start building next spring.

Ditto from me. We are planning to start our off grid home build in September 2024 and I am scouring the internet for DC lighting options. I had been planning to use AC for appliances, but this thread is changing my mind. I need help! Thanks.

 

[HarryN]

SunDanzer makes 48 volt and 24 volt DC refrigerators in case that is helpful.

For a lot of people, the refrigerator is one of the largest "total " power consumer.

We could not make it without the microwave and coffee maker and those can be powered pretty reasonably with a moderate size 120 vac inverter.

There are USB ports that run from 12, 24 and 48 volt so that is not a big deal. Same for LED light strips.

To some extent, it comes down more to philosophy than one approach being better or worse.

I think that you will end up with some AC no matter what, at least sometimes.

 

[OzSolar]

Keep in mind that most (all?) DC refrigerators/freezers are not self defrosting/frost free or whatever it's called.

Speaking from experience I can offer that the higher your regions humidity and your usage (opening the door) you will be regularly mopping up some moldy condensated water from the low spots of your DC fridge.

From a $/cubic ft and convenience you'll have a hard time beating a middle of the road fridge from your local big box store.

 

[JRH]

Do you have links to 12V DC fridge that shows this? I once looked as a DC chest freezer and even though it was more efficient (a lot of it was because it had thicker insulation not because it was DC) I found out the quality was crap.


That is only because of cheap LED lights and/or cheap inverters. Never had issues with LED lights flickering on low frequency inverters.

I agree.. For the last 2 weeks , conducting a test, I am running everything off solar…24/7.

…the lights , incandescent, LED and some old compact fluorescent's have never flickered… at all…
I have had the same lights for years , and on Shore power they don’t flicker either…

Not sure what people are buying that causes a flicker…

Jus sayin…

J.