Are there any tube amps that don't give off any---

I hear good things about the Element, Purify and a few others.

Hi Ralph, what happened with your prototypes? Any closer to your class Ds?

Daveyf, my understanding is that Carver amps run cooler than most.
I am not sure if you can do this but, if you have a basement you can do what I did which is to make a shelf 12" under the floor and drill a few discrete holes to run wires. I also run fans. I put pots on the supply lines so I can control fan speed. I can slow them down to the point of not being able to hear them at all upstairs. Check out my system page.

"I don’t think you are ever going to find an amp that runs totally cool.   There is electric flowing through it and that is going to generate at least a little heat"     Correct!      All gain devices will generate heat, while in operation (none are 100% efficient), but- not all gain devices are defined as, "THERMIONIC" (requiring some heat to operate in the first place).      The operating parameters of one’s gain devices and how much output power is being called for, will determine how much heat finally results (aside from a filament’s contribution), while signal is being amplified.      ie: Some tubed Carvers = cool enough to touch / some FirstWatt (Class A, SS) = too hot to touch (for the sensitive)

I have a small integrated amp with 6C33C that put out a lot of heat and I biased these low, to the point that the entire amp innards get very hot, I set a Noctua silent fan underneath which helps with the heat but in the OP's case will only move the heat away from the amp into the room possibly making it hotter, I found a company which specializes in all these cooling solutions ACINFINITY you might be familiar with, like others have stated it may be easy to run a duct to the outside or other room with an inline fan, these are supposed to be quiethttps://www.acinfinity.com/duct-fan-systems/
32 dba is the equivalent of a quiet rural area so it should be pretty silent
Just my 2c