Mechanics… man, the big piston air pumps make a lot of heat…

[Magnum Man]

At least between the pump, and the manifold… release of air pressure makes cold, so no heat issues between the manifold and the use device ( air stone or whatever ) I have a big piston pump outside to aerate my Tilapia tanks… I’ve been working through hoses that go from the pump, to the manifold… days with a 100 degree heat index, caused the factory vinyl hose, and my 1st replacement, a silicone hose to fail… 3rd try seems to be the ticket… I’m using a cord reinforced automotive grade chunk of hose, between the barb fitting on the pump, & the manifold inlet, and that has so far lasted through a week of 100 degree heat index weather… both of these are 3/8" barb fittings, so larger than the normal air tubing... & I use a hose clamp on the pump side where the barb fitting is hotter...

I also have one ( a piston pump ), for my biggest group of tanks in the house, but no issues with hose failure, as the house is air conditioned… the outlet is still hot to the touch, from the piston pump… the outlet air on these types of pumps must be 50 - 60 degrees, or more, hotter than the inlet air, and if you are drawing in 100 degree air, it puts the outlet air hotter than standard hoses will work under pressure…

Initially I wondered if that would “heat the tanks at all” but with the "release of pressure cooling", I’m not seeing any heating… my Asian Bamboo tank, is 70 degrees, and doesn’t show any signs of additional heating from the 20 inch bubble waterfall…

 

[GaryE]

I have wondered about that. I aerate via 2 linear piston pumps, with valves running air driven filters. I used no airstones or wands or any such devices - just box and sponge filters.

The pipes are very hot on the fingers, and the cord reinforced initial hoses get discouloured brown with time.

I think they do affect temperature in the tanks, or in the room. In winter, the room is usually around 21c, with a lot of the ambient heat coming from the dehumidifier. The level of insulation's very high, and the room is tight.

The tanks not distant from the air pipes sit at 22-23. If I have 3 feet of airline snaking down to a lower level tank, no. I run no in tank heaters, and the lights are suspended above the tanks, so I assume the extra degree or two must come from the endless influx of warm air. In summer, I see it less, as the warmer room temps are the tank temps. But in winter, I have wondered about that. Honestly though, I have just wondered and not looked into it.

 

[MaloK]

I never tried, but holding an air output and a thermometer in a sandwich bag for a minute should tell if there is a big difference.

For your exterior tank that gets really hot, you can coil a length of the tube in a bucket of water before entering the tank. making a kind of radiator.

 

[Magnum Man]

the tanks are in the shade, & Ideal temperature for farm raising Tilapia is 87- 88 degrees, so with nights cooler, most days my tank heaters run at least a portion of the day, even when it's hot... and I honestly don't think with the pressure drop from compressor to air stone I don't think there is any heat transfer from the air... in @GaryE ... situation, I do think the compressor warms his fish room some, which in turn, can slowly heat the tank some... but I don't think any heat is transferring from compressed air, from the pressure drop cooling effect...