jgarciav,
If people are in the hall sometimes, but there are permanent workers in room 25, put ap-L01.0.19_sw240.4_p0/36 in that room where the permanent users are, so that they can have better performance. AP ap-L01.0.255_sw240.4_p0/34 should be on the 2.4ghz band inside the Sala De Profesores. Not all devices use the 5ghz band, so ap-L01.0.255_sw240.4_p0/34 is a "black hole" to any devices in the Sala De Profesores that are 2.4ghz only and they have to try to connect to devices that are further away.
I think you do not have enough AP density to make your single-radio access points operate only on 802.11a. Your coverage is further reduced by obstacles in your diagram. Clients should have line-of-sight with the access points they are connected to. If a client cannot "see" the access point, they can expect reduced coverage. Always place an access point in a space where users will be permanently, because if a group of users cannot "see" the access point they are connecting to, it is bad, because their devices would try to connect to other access points which are also bad or worse.
Lastly---load balancing is not something that should be expected. It is not anything that is in the 802.11 standard. It is normally used when two access points are in the same physical space and you want users evenly distributed. It should not be considered between access points that are not in the same physical space.
If more users are on one access point than another, that is because one access point cannot be "seen" by users for some reason. That access point should be relocated near to users to make it more attractive.