URGENT:
Hi guys,
I am an architecture student proposing a self-sufficient hydronic heating for buildings for a final project. Basically I have a 12V 10W DC micro-hydro turbine that I am using.. this one-
https://www.amazon.com/Turbine-Generator-Micro-hydro-Charging-Charger/dp/B01M8NQHWT

I want to connect a heating coil or a wire that could heat up in about 5-10min or sooner. Any suggestions what can I use? Can i directly connect a nichrome wire 1'0" long to the wires? will that heat up?

 

It depends on the diameter of the wire. To use the full output you need a resistance of 14.4 ohms. (R = V^2/p = 12^2/10 =144/10 = 14.4 ohms)You need to find a nichrome wire with a resistance of 14.4 ohms per foot. (Or as close as you can get from standard wire gauges.) If you plan to use the water supply to drive the turbine it is probably not legal. (It is not in the UK.)

Les.

 

Thank you Les for your reply. This is a just a project proposal for a sustainable energy project. I am just building a prototype. 34 guage nichrome (0.13mm thick) has 16 ohms/foot resistance. Will it heat if I directly connect to the wires output from the turbine (as in the link)? Thank you again

 

Will it heat if I directly connect to the wires output from the turbine (as in the link)?

Every resistance will heat when current flows through it. What you have not told us is how hot you want it.
You have 10 watts to work with. You can buy a 15 ohm resistor and it will heat exactly as much as 15 ohms of nichrome wire. The surface area has a lot to do with how much heat radiates and is thus lost to the air. What is your goal?

 

Hi there, Thank you. My goal is to heat up ambient air around the wire/ coil, so I think if I have a coil of wire at 70F (room temperature)- I would need to raise it by approx 50F to make it to 110F. I have no specific requirements, I just need to heat up the wire so that we can feel the heat. Any suggestions?

 

The heat will dissipate into the air with exactly as much energy as you put into the resistance, whether it is a foot of nichrome, a light bulb from a car, or a resistor which you bought. When you say you want a human to perceive the surface temperature we have a useful statement.

A light bulb seems an obvious way to demonstrate energy flow. If you buy a 10 watt resistor, it will get hot enough to hurt your skin. If you buy a 20 watt resistor, it will be warm enough that it might get uncomfortable after a few seconds.

The time required to heat depends on the mass of the resistance. I have given you examples that will arrive at equilibrium in a few seconds.

 

Yes exactly, I want the heat to dissipate into the air. Thank you for the explanation mate! I really appreciate it.

 

Thank you for the explanation mate! I really appreciate it.

Now for the part you did not ask me. You don't seem to have a good grip on thermodynamics. As a student of architecture, you will have to deal with the energy efficiency of buildings. I recommend, "Trane Air Conditioning Manual" chapters 1, 2, and 3. That will be enough for you to realize that anything that, "takes 5-10 min" to come to equilibrium on 10 watts of energy will not be detectably warm by human standards. That large of a mass would radiate heat over a rather large surface area and never get much hotter. You need to get some ideas about heat vs temperature, watts vs B.T.U.s, the time constant of concrete block construction, how sunlight passes heat through glass, and how the entire building, "envelope" is used to calculate energy efficiency.

You don't intend to design air conditioners or furnaces, but you need at least a vague idea about how and how fast a building accumulates and dissipates heat.