Compare the whole route
Review four things together:
- Comfort: Which room does each head serve? Ask why that location was chosen, how it serves the occupied part of the room, and what happens when bedroom doors are closed.
- Appearance: Where will holes, line covers, drain outlets, brackets, and outdoor equipment appear? Ask for the cover color and a photo or sample of the proposed finish.
- Access: Can you reach the normal filters? Can a technician service the equipment without removing permanent cabinets or finished walls? Who provides any required ceiling access?
- Water: Have the installer trace the drain from each head to its approved outlet and explain whether it uses gravity or a pump. Ask how drainage will be tested and how the route will be protected where needed.
These are equipment-specific details. For example, Mitsubishi's SLZ-KA09/12/15NA cassette installation manual requires accessible filters, suitable ceiling support, and drainage testing during installation. That older cassette manual is an example of why a drawing must also satisfy the exact proposed models' instructions. It is not a placement rule for every wall head. Mitsubishi installation manual, RG79Y612H02.
Put responsibility in the proposal
Ask the quote to name who owns mounting, electrical work, wall penetrations and sealing, drainage, permits, startup, and any patching or painting. If another qualified provider handles part of the work, identify who coordinates it and what must be finished before installation.
Our preference is a workable, serviceable route with a clear finish plan. We would reconsider a more discreet location if the designer shows that it compromises the exact equipment's installation requirements or the room's comfort needs. Ask for that explanation before agreeing to a change.
Your next step: Send the same marked photos to your finalists and request revised placement drawings with written responsibilities. Compare those drawings with the complete prices, rather than approving a head count alone.