I think the issue has s largely been explored and solved but I’d like to add something to the mix.

Complexes have hot water pipes running from the water heaters on the lowest floor up to all the suites. Usually they are stationed somewhere around the center of the main building, sandwiched between a commons hallway wall and an apartment wall.

The amount of heat that these can radiate is insane, especially if there’s a hot water circulation system in the building.