One loft quote uses daily average temperature and floor area.
THE NEWCASTLE UPON TYNE FIELD GUIDE / AIR CONDITIONING
Air conditioning installers in Newcastle upon Tyne
When is the loft actually uncomfortable? Record that Newcastle upon Tyne room's glazing, use and peak hour before a unit is sized.

START WITH THE PROPERTY
Record the hour of discomfort
For a Newcastle upon Tyne loft or sunny room, note when the temperature becomes uncomfortable and when the room is occupied. Window area and afternoon sun can matter more than a rough floor-area estimate.
BEFORE YOU ACCEPT A QUOTE
Tie sizing to the stated problem
The quotation should explain the calculated load, where air will be delivered and how the outdoor unit will be reached. Ask how the proposed setting performs when the room is most often used.
ILLUSTRATIVE QUOTE COMPARISON
Is the system sized for the hour you use the room?
Another assesses afternoon sun, glazing and occupancy at the time of discomfort.
Compare the design cooling load and proposed indoor position. A room that is cool at noon may still fail during evening use.
ANOTHER PROJECT AT THE SAME ADDRESS?
Explore the other options in Newcastle upon Tyne.
NEXT STEP IN NEWCASTLE UPON TYNE
Locate the outdoor unit and drain.
Room sizing should be paired with a physical installation plan. Ask how pipework and condensate leave the loft or sunny room without unexpected visible work.