TEC applications

MUCH more detail, please!

I am searching about thermoelectric materials in order to built a devise in order to contribute to sustainability by any mean. I will use it for temperature control either for power generation.Can you suggest me any possible application?

Do you know if I can make use of thermoelectrics in order to design an air-conditioning system for the house? How efficient it is?

Thank you!

Using thermoelectrics for air conditioning is horribly inefficient. I do not recommend that you look at this if you are concerned energy use. Power generation may be possible, but the inefficiency is rather high for this as well, though if you have a waste source of heat, the power created is better than none at all.

As others have said, the efficiency of TECs is really low. The only place I've seen them used to generate electric power is in the pilot safety valve of water heaters and furnaces. In this application, a single thermocouple in the pilot flame generates enough current (at a tiny fraction of a volt) to hold a spring-loaded steel bar to an electromagnet. If the flame goes out, the current stops and the electromagnet looses its field, so the bar pulls away, closing the gas supply. There is only enough energy to hold the valve open; the operator must press the valve to open it while lighting the flame.

As Garth implied, you can get higher voltage from a thermopile, but the efficiency is still very low. I will be surprised if they can increase mileage by 7% via exhaust heat recovery of any kind, and extremely so if they can do it with TECs.

http://www.marlow.com/technicalinfo/frequently_asked_questions_faqs.htm

has some good information, although the information I saw, including the coefficient of Performance values, is for cooling purposes, which of course is the opposite of what you want to do.

I do believe there is a German company in the process of using the engine exhaust gasses with thermopile's and expect a fuel saving of up to 7%.

You should Google this I do not have a link.

Yes, I just read about that in one of my trade mags...

They are hoping to get about 1 kW output, so reducing the load on the engine, they also said it would not replace the alternator but a smaller one can be used...

We use a small cell to produce a simple de-humidifier operating from 24VDC. It might be less electrically efficient than a standard freon cooler but it is so much smaller and half the cost.

I don't believe that they have much of a future in energy recovery but are excellent for these specific applications where space and cost are important.

The best way to recover energy from something like exhast is with ORC Organic rankine cycle.

Hello again

Because I am an Industrial Designer I don't have deep knowledge of TEC technology. Nevertheless I understand the inefficiency of Peltier pumps in contrast to other systems of gathering waste energy. However I find TECs extremely interesting due to their unique characteristics (ease of controlling cooling and heating, absence of mechanical parts, noiseless, environmental friendly).

I am focused now to generation of heating or cooling.

Some of my questions are:

· Is the energy consumption for controlling temperature lower or higher than conventional methods (Air-conditioning systems, stoves, electric heaters, boilers etc.)?

· Whats the size limitations of TECs? - Is it possible to produce a bigger size (e.g. size of a tile)?

· Can the cost of TECS be reduced?

Thank you

The energy consumption is considerably higher than any of the devices mentioned.

The largest array I have seen was a square between 1.5 and 2 inches square, with somewhere around 400 to 500 elements. The heat sinks are considerably larger than the actual TEC array.

I have one which is sealed, so I can't actually see the array, but judging by the screws that hold it together, the array is about 1.75" square. One heat sink is 4" x 4.5", and the other is a 5" square.

It would be possible to mount more than one array on a singe pair of heat sinks, but you would for sure need forced air (or water...) on the heat sinks, which of course consumes more energy.

The cost of anything can be reduced if it is produced in very large quantities.

You have mentioned several of the advantages of TECs. It is the only device I know of that can switch from cooling to heating simply by reversing direction of current. I once made a device to measure the dewpoint using a TEC array to cool a mirror, and observing the reduction in reflectivity of the mirror when dew formed. Under some conditions, it was necessary to heat the mirror to dry it and/or melt the ice before again cooling it below the dewpoint. The TEC was perfect for this application.