It's definitely the 24v versions that I'm looking at now if it's the US or Jap version is questionable and I'll figure that out:

http://www.jab-tech.com/Iwaki-RD-30-...p-pr-3849.html

I believe that you do have a point with the heat dump problem but I think that if you can regulated the voltage, you can control the heat dump and hopefully the noise with not too much of a hit on pressure.

But since I have no experience dealing with this pump, the noise would really tick me off more then anything else so that's why I would like to see what people have experienced with these pumps.

BTW, I do appreciate all the replies.

Thank you.

So, anyone have any 1st hand experience with the RD20 and/or RD30?