I am working on a new system design and am wondering if I have a choice to go all AC or all DC, which would make better use of my batteries? I know I will eventually have a blend of both but, when making a choice between appliances (say, a coffee maker), which are kinder to the batteries (assuming they both use the same power and have the same capacity.
AC or DC appliances
- Thread starter jbhudetz
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Maast
Compulsive Tinkerer
In theory running everything DC avoids inverter losses, HOWEVER thats only true if everything you want to power is within a few feet of the battery. You will actually lose more power running long relatively low voltage wires through the house, in addition the wire sizes for 48, 24 or especially 12v required for usable amounts of power will be so much larger you'll go broke running wire. Also all the disconnects, breakers, etc are more expensive for DC components, a lot more expensive.
If it were me I'd run nothing but straight 120V and 240V AC since the wiring losses are so much less and it's a "standard" power install.
If it were me I'd run nothing but straight 120V and 240V AC since the wiring losses are so much less and it's a "standard" power install.
Just be aware that anything that heats up or uses a compressor uses a LOT more power (watts). You may want to do some calculations on, say, running a coffeemaker on an alcohol stove, vs 120vac coffee maker with invertor, vs other fuels as propane has gone up a lot over the past 20 years. Propane has at least doubled from 1998-2004 when I had it. Just do your best to estimate how much it will cost to run your coffeemaker for a week on various fuels then extend that to a year.
In some states, like Michigan, total cost of grid power (with all fees) is only about $.10/kwh. While electric heaters are expensive, at $.10/kwh it might be cheaper than heating via kerosene, alcohol, etc. They do make alcohol heaters for boats (marine heaters), and I have one. They are fine for a room up to 150 sq ft up to 8 ft high, or 150x8 = 1200 cu ft.
In some states, like Michigan, total cost of grid power (with all fees) is only about $.10/kwh. While electric heaters are expensive, at $.10/kwh it might be cheaper than heating via kerosene, alcohol, etc. They do make alcohol heaters for boats (marine heaters), and I have one. They are fine for a room up to 150 sq ft up to 8 ft high, or 150x8 = 1200 cu ft.
Maast
Compulsive Tinkerer
Hah, if you want heat, buy one of the little forced air diesel heaters that run on 12V, insane amount of heat and they sip the fuel. I have one on my 30' boat and it'll roast me out of the cabin.
Wife and I are planning a little cottage at the WA coast and we'll be using diesel heat for both hot water and space heating.
Wife and I are planning a little cottage at the WA coast and we'll be using diesel heat for both hot water and space heating.
DRLExpress
New Member
- Joined
- Oct 21, 2019
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Do you have a link, Thanks
KBWaldron
Solar Enthusiast
Yeah, I'm going with diesel for furnace, water heater and generator in my planned RV. My truck engine will be diesel as well. No propane at all. Induction cooktop and convection microwave. No oven, there are cheaper storage alternatives for my pots and pans. 
Finally, custom in-counter 24V fridge/freezer. I have never understood the open the door and let the cold fall out design of RV fridges.
And boy, am I off topic.
Finally, custom in-counter 24V fridge/freezer. I have never understood the open the door and let the cold fall out design of RV fridges.
And boy, am I off topic.
Maast
Compulsive Tinkerer
Sure, Amazon example just search around on there for a good deal, don't buy the 8K because they're only rebadged 5K heaters being overdriven and they dont last. The one I have on the boat is a high dollar Espar version of this, but the web reviews of these chinese clones have been very favorable. For the cottage I'll be going with an actual Planar
Maast
Compulsive Tinkerer
Sorry OP for going even more off topic. Have you looked at the Planar diesel hydronic heaters? I've spent an immense amount of time researching this and they look to be the best bet to provide both space heating via baseboard radiators and domestic hot water using a heat exchanger coil in a tank. If you've got a better answer I'd love to hear about it. Toyo stoves are also an answer for space heating but they're expensive and still leaves domestic hot water to deal with.Yeah, I'm going with diesel for furnace, water heater and generator in my planned RV. My truck engine will be diesel as well. No propane at all. Induction cooktop and convection microwave. No oven, there are cheaper storage alternatives for my pots and pans.
Finally, custom in-counter 24V fridge/freezer. I have never understood the open the door and let the cold fall out design of RV fridges.
And boy, am I off topic.
DRLExpress
New Member
- Joined
- Oct 21, 2019
- Messages
- 8
Thanks, was not familiar with those.
KBWaldron
Solar Enthusiast
I’m looking to get the Truma Combi D6. By no means cheap, but provides both heating and water heater features in one device. I value efficient space usage and single efficient fuel source over cost.
Diesel is cheaper and more energy dense than propane, and will give me much more time in the boondocks than propane.
Diesel is cheaper and more energy dense than propane, and will give me much more time in the boondocks than propane.
Maast
Compulsive Tinkerer
If you want to go top quality and spend about double of the above, Heaters4you has the best prices by far on Webasto, Espar, and Planar. I personally like Planar. Awesome value and reliability. When we lived in Alaska I used a 2D in a uninsulated 12x8 hunting shack with the trucks battery for up to a week at a time and we were all toasty and it only used about 6 quarts of fuel going almost full time. Looked at the Trumas, a little too small. Heaters4you has a ebay store too. Never had a single problem ordering things from them.
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