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Any inline 48v water heaters?

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Swing

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Feb 22, 2022
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Hi, for a project I am looking to heat water directly with 48v. With at least a few kilowatts of power. Right now I only see 230v heaters or 12v/24v low power boilers.

So it seems to me that I need to make a small box with some 48v heating elements (for example 2 times 1.5kW) and run the water through there. Which would work.
But it isn't water, it is going to be some kijd of glycol/coolant type, which I am not sure if the immersion heater elements like that?

Has anyone seen some inline water heaters on 48V? Weather it is a pipe that gets hot or it is a premade box from Asia with some elements, both is okay.
 
Yeah I meant inline, not immersion.

But the most likely outcome is to use some of these immersion heaters in a small box and run water through there, as a big inline heater.
 
Heating elements will easily fit in pipes. They need to be oriented so a bubble will never form. I think the best deal around would be used stainless hot tub heaters. Several could be linked in parallel or series and nothing wrong with using 240V elements. You should use the highest voltage possible like the array voltage. Multiple heaters will allow trim for array excess. Heating water from batteries isn't a good idea unless in a RV.
 
Swing said:
Hi, for a project I am looking to heat water directly with 48v. With at least a few kilowatts of power. Right now I only see 230v heaters or 12v/24v low power boilers.

So it seems to me that I need to make a small box with some 48v heating elements (for example 2 times 1.5kW) and run the water through there. Which would work.
But it isn't water, it is going to be some kijd of glycol/coolant type, which I am not sure if the immersion heater elements like that?

Has anyone seen some inline water heaters on 48V? Weather it is a pipe that gets hot or it is a premade box from Asia with some elements, both is okay.
Click to expand...
If using 48vdc panels, wire some in-series for ~100+, or even 200+ vdc.
Or just measure the resistance of the element, plug in Ohm's Law, and design from there.
 
@Delmar
Any idea on prices for these units?

The purpose for this topic is indeed an RV and reusing braking energy.
In my house I run a big 48v setup, which includes an ac system, and it runs through 230v inverters.

Directly at 48v would be nicer, but I doubt if it is worth it if it costs a lot more than seperate inverter+ac system
 
Swing said:
Haha not yet.
I guess it is already available in EV vans, but those are high voltage systems from factory.
Click to expand...

I really want a full size plugin hybrid RV. Talk about a vehicle that could really benefit from it.
 
Deepwoodssolar said:
If using 48vdc panels, wire some in-series for ~100+, or even 200+ vdc.
Or just measure the resistance of the element, plug in Ohm's Law, and design from there.
Click to expand...
Agreed.
Why do so many folks say to
switch to a "dc" heating element?
Pure resistance doesn't care
whether it's AC or DC....
 
cs1234 said:
I really want a full size plugin hybrid RV. Talk about a vehicle that could really benefit from it.
Click to expand...

Yes but is hard to modify a vehicle into a hybrid, though not impossible.
It is much easier to just add a 48v system with solar, and then have the 48v feed the 12v, and turn the alternator off. That way you can also save some fuel, of course it is a bit less.
 
The energy required to heat up water for taking a shower is huge. For an RV I was using the engine to heat it up. A plated heat exchanger was used. One side was antifreeze, and the other side was clean water. Heat up the engine to 60-70C, run the pump, and take the shower.

Adding a thermostatic mixing valve to the output of the heat exchanger does a nice job.

But this was 10+ years ago. Now I'm using a camping gas water heater.
 
Samsonite801 said:
Hey, I talk to myself all the time, that's how I make decisions when I get confused about which way I ought to go on hard topics hehe...
Click to expand...

I totally get what you mean, sometimes we argue for awhile until we figure out how to agree on stuff but eventually we usually come to synergy...

The problem with this forum software though, is I can't give the other me a 'Like'...
 
brum said:
The energy required to heat up water for taking a shower is huge. For an RV I was using the engine to heat it up. A plated heat exchanger was used. One side was antifreeze, and the other side was clean water. Heat up the engine to 60-70C, run the pump, and take the shower.

Adding a thermostatic mixing valve to the output of the heat exchanger does a nice job.

But this was 10+ years ago. Now I'm using a camping gas water heater.
Click to expand...

If you dont use a lot of warm water, then the amount of energy is not too bad, but it draws quite some power. Doing that on 48v solves some issues, so you dont run it through an inverter.
 
Whatever works with water will perfectly fine work with glycol. The approach you are considering (replace AC elements with DC elements in a suitable inline heater) seems to be appropriate.

Out of curiosity - would you share the purpose of this device? What are you going to heat? And have you calculated the required energy per day?
 
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