HERMS copper pipe size

Thinking of eventually building a herms system.

IT seems most people go for 1/2 inch copper tubing, that I have seen. Is there a benefit to this? 3/8 is a fair bit cheaper, and wouldn't it have more surface area to dissapate heat?

 

3/8 has less surface area...water would spend less time in coil also...it is all about efficiency, if you want things to happen faster, go with 1/2, if you want to spend less money, go with 3/8. I went with 25 feet of 3/8, and then when money was available to put into the hobby, I added another 25 feet with a compression fitting connector.

 

Ok. I currently use 3/8 for my chiller, 50 feet with a connector. I will look at the price difference and decide.

 

With a HERMs coil, you are at the mercy of your pumps capacity. 3/8" copper will have more resistance and you will have significantly less flow which may or may not be a problem.

3/8" is fine for an IC because typically you use residential water pressure.

Ed

 

Good point. I hadn't thought of it that way......

 

Just to clarify things up for the many people that read this, please specify OD or ID when you say 1/2" or 3/8", please thank you.

 

1/2" is id for rigid copper pipe, 3/8" is od for copper tubing. A 3/8" to 1/2" rigid adapter will not join the two, found out the hard way yesterday. You need a 3/8" compression to 1/2" slip fitting to accomplish this.

 

I currently have 1/2" OD copper HERMs and I have to restrict the flow to such a degree that I think 3/8" would have been a viable option.