Air Pump - eHLT circulation - Who, What, Where?

Hey guys,

Finally going to brewing again this week and wanted to ask a few simple questions. I've read that several members are using air pumps to keep the water moving in their HLT to ensure even heat distribution. This seems like a simpler and cheaper solution then building a stirrer or adding an additional pump. Being that my keggles are not insulated yet, my probe is on HEX exit, and I'll be using the HLT water for sparging I have the follow questions?

1) Is there any science to the size of air pump required? I'm planning to have 10-12 gallons in eHLT, how many gallon rated air pump should I buy?

2) Would it be best to use a small airstone, or a longer air wand?

3) Would a stainless airstone be required, as temps could easily reach 180 deg

4) What is a safe way to fix the stone to the bottom of the HLT so that is does not touch the element and melt?

I know several members use them, if so please share what model and what size HLT you use.

Thanks
Squeeky

I don't have any experience using an air pump, but if I were trying it, I'd get a 24" piece of 1/4" SS tubing to deliver it to the bottom of the tank. Drill a hole in the top of the keg on the edge that wasn't cut out and install a rubber grommet that will hold the wand in place. You wouldn't need an airstone. You want the bubbles to be big.

I promise I searched prior to this post. However just ran into this:

https://www.homebrewtalk.com/f51/using-aquarium-air-pump-stir-hlt-surprisingly-works-195561/

I'll take some pictures tonight when I get home, but essentially I had an aquarium pump that I purchased for oxygenating my wort that I didn't ever use. I decided I'd give it a try as a eHLT stir device.

I have the pump mounted to the lid of my HLT and it's connected to the bottom of the keggle with a normal plastic air hose. I ran the hose down the side of the keg and in through one of the holes in the side of the skirt. I used what amounts to a 3/8" weldless fitting with a 90 degree elbow and a barbed fitting on the outside. I put a small check valve and a pressure sensor in line with the pump so that I can measure the depth of the water in the vessel as well.

I was pretty skeptical of this approach until I tried it. However, after some testing and after a half of a dozen or so brews, I'm confident that it works incredibly well.

I read in an old thread to pump the air through your sight glass. My sight glass is 3/8 I'D, most airlines for aquarium pumps are much smaller. Any why didnt I think of that way to easily seal and connect them.

I too have an interest in using an air pump for the HLT. Anyone else with personal experience or photos of their setup?

This may just be genius and exactly what I was looking for. Subscribed!