heat exchange

[windspeed]

how efficient is this type of heat exchanger

forgot the pic here it is ------------I hope

Windspeed

[vawtman]

Hi Windspeed

 That setup is often used in closed loop systems to heat domestic water.Usually the coil extends almost to the top.Very efficient and nice cause not much to fail.The overall efficiency probably depends on the mother that feeds it.

[KEG]

if you have a brand name and model and ser. number on it the manufatur will have that info pubished, as to its heat exchange and tempeture rise at a given supply temp.

[kurt]

windspeed, when you upload a picture to this server always make sure it has the file extension on the end of the file name like .gif or .jpg etc. and if you use the file renaming tool in scoop to rename your files after they are uploaded make sure to tack the proper file extension on the end of the file name as that silly tool does not do it automatically. not all browsers will display the image properly if the file name does not have a proper file extension therefor someone mite come along and not be able to view your pictures......

[dnix71]

My broswer shows his picture with a gif extension. That format is as old as the web, but it still causes my broswer trouble sometimes. jpegs are universal, but usually larger.

gifs can be easily animated, but animated jpegs are rare.

[paborralho]

Hi

I think it can be put in two ways:

Efficiency (no losses) must be nearly 100% because the losses in this case are from the main tank to the outside.

Effectiveness (how much heat you can transmit) is greater as the Temperature diference rises. You won't be able to equal the two temperatures-  the coil and the tank, as the system will not work when the 2 temperatures get near. There will always be a difference. Of course a copper coil will exchange more energy than an iron one.

I think this system is good in this case:

A solar panel made of iron, like those water house heating radiators you can find in junk, filled with oil circulating through the tank.

Advantages: no rust in water, no water freezing in the panel.

I don´t know if oil if good for termosifoning...

That picture is very nice.

Paulo

[sbotsford]

They are very efficient.  No flue channel for them to lose heat, like a conventional gas heater, so they hold hot water for a very long time.

You'll get slightly faster transfer if the hot water goes DOWN through the coil.  This uses the hottest water from the boiler to heat the hotter water near the top of the tank, and the coolest water at the bottom of the coil is still a bit warmer than that the water at that point in the tank.

The one in my basement uses 30 feet of 1" stainless tubing, coupled to 1/2 supply/return lines for a 40 gallon tank.  It doesn't recover as fast as a gas heater. If I got another I'd get one sized to absorb the full output of my boiler.  Right now it won't, and so the boiler cycles a lot if the water tank is the only demand on the system.