Well, it's saying within about 18 ft. you can feel a change, and up close it is about the same as lava. While this might be slightly excessive imo, I think that it definitely should emit more heat than what you're thinking. Remember the survivalist generator is something you made with you bare hands, from just some scrap iron and rocks. The fact that it can burn coal basically means it's just a fancy box of intense heat. Obviously this isn't insulated (as I'm assuming normal generators are) and isn't as efficient as a normal generator; the extra heat is let out. That's my take on why it might be so hot ^^.
normal generators are not insulated, or at least the ones i've used aren't. they're basically just a small car engine hanging on a metal frame, that generate electricity by consuming fuel. real generators aren't made out of stone, but if anything, the stone would help absorb the generated heat.
either way, this doesn't explain why they are producing heat on par with pyrotheum, which is clearly stated as the hottest thing in the game. that can easily be explained away: iskandar hasn't configured heat levels of the blocks, he's just said 'this block produces heat'. this is confirmed by the fact that everything that produces heat, produces the same heat apparently. blazing pyrotheum is the same as lava, which is same as survival generators. dunno what the heat level is on the furnace, as i'm using the slab furnaces.
I've never had a major issue with their heat radius, yes they generate heat, but it's far from anything to worry horribly about. I do tend to place them on the opposite end of the ship from where I tend to "camp" but you can use them just fine without conduits. Particularly when discussing powering a cell...... there is little reason to camp right next to them.
all heat, including the ambient heat of the map during daytime, is raising your temperature. you will eventually start suffering heat stroke if you just put these things wherever, without consideration of frequency of presence. this is why i put all heat generating blocks in a tightly packed group by the broken engine (which is an area i never go to normally). i also keep 1x1x1 pits filled with water at various convenient spots across my base, so that i can hop into them during the night and quickly drop my temperature to 34 degrees.
Also remember that you are on a giant dustball of a planet that is starting out hot. The open air isn't well ventilated as far as dispersing heat goes.
open air is better than enclosed spaces, it doesn't matter if there's any movement or not. it will provide at least a minor dispersal of the generated heat. realistically, if i were to put the survival generator on the roof and then wrap a pipe around through the door, its heat should not enter the ship at all. this is why i say that iskandar should look into a way to make it possible to block off heat generating blocks with walls and/or water. it's more realistic and fun that way.
Now there's a hell of an idea for enviromine or an enviromine add-on. Air conditioning. Could add AC units that can change the temp to whatever you prefer and are powered by RF. I wonder how difficult it would be to make both kinds; standalone and full AC installation. A single unit that works like the heat sources basically except only emits from one side. Full installation with a main unit and ducking to move the air around. Time to have a chat with the mod author and/or rehash some old java knowledge.
this is exactly what i've been thinking about for over a week now. 'i'm in a spaceship, why isn't there an environmental control unit in here? why can't i just build an A/C unit? hell, even a simple fan that provides cooling for one block in front of it...'