Those tapes will do your fuel economy no good whatsoever!
Get those going and your foot naturally becomes heavier!
On the A/C, have a look at this thread from post #3 onwards :
https://www.volvoforums.org.uk/showt...28#post2743928
The solenoid valve block mentioned also controls the heater valve, if that isn't operating it defaults to hot so the A/C will be trying to cool heated air - fine for clearing the windscreen in winter because it's dry air so clears it quicker but in the summer can leave you feeling somewhat less than cool!
Make sure that you can select the different places for the air to come out and the recirc button works too, everything is controlled by those valves from cabin temperature to heater valve on/off (it's only ever off on Minimum temp) to direction so will effect the airflow if none are working.
Also check what temperature you have the heater controls set on, if not minimum it will only cool to whatever you've set it at, even when working correctly. Worth pulling the lens off the interior light and vacuuming there with a dusting brush on the end of the vacuum nozzle - the cabin temperature sensor is in there. Check you haven't defeated the A/C as well by releasing the A/C button - it should be in.
If all else fails, you'll probably need to have it regassed. If it's done properly, the system will be vacuumed down (gas recovered), leak tested, new oil and leak-test dye added (usually optional but useful to have) then regassed with the correct amount of gas and tested.
The "high street" people like "Fik Wit" will simply add gas and see if the temperature on the vents drops. Any moisture present inside the system will still be there and may impede the efficiency of the A/C system. Vacuuming the system down will remove the moisture from the system as it will boil off any moisture inside the system.
Check your solenoid valves are working first though before shelling out on a regas as you may not need the regas if it can be fixed simply and easily as per my answer in that other thread.