RTU in training room

[rmusa]

Office space and training room with 50 people ~2000sf.
Office space load is 3 tons, training room load is 10 tons
Existing RTU-1 is 7.5 ton unit only and it will serve office (cannot demo it and have to use the remainder capacity). The remaining 4 ton will serve training room.
The training room needs 6 tons more. The ventilation load is 950 CFM.
How to select the RTU-2 for Training room? 320 CFM will be picked up by RTU-1 for ventilation and 4 tons for cooling.
Training room needs 630 CFM of OA.
Option 1:
Is it better to select standard 20% OA unit that provides 630 CFM OA? 10 ton unit will provide 800 CFM of OA and heating /cooling. RTU-1 does not de-humidify very well It has a discharge of 59degf. Can the 10 ton unit pick up all dehumidification load for training room, if equipped with HGRH?
The Latent Btuh of the unit meets the load calc Btuh, but the sensible is lot higher than what is needed.
Option 2:
Select high OA RTU with 50% OA or 100%OA. More expensive.

Which is better option?

 

[willard3]

What is happening in the training room?

 

[dbill74]

Why can you not Demo RTU-1?

 

[walkes]

Use a small HRV to ventilate the training room and condition it with ductless split units. If you are putting some air in from RTU-1, you run the risk of poor temperature control or duelling thermostats.