The problem thse days is that even with the CH off, some of us have a great deal of heat-generating electronics - much more than we used to have. The other problem is that it's just getting hotter for longer [in the year] anyway.
There used to be a nutter here who reckoned you could cool a house from 35 to 21 and drop humidity from 80%RH to 45%RH by planting some geraniums outside. Presumably he's been carted off to the [superheated] funny farm by now?
I ask you. Fancy being dim enough to think that if you open the windows on an outside temperature of 35 you can defy all known laws of physics and the temperature indoors will somehow drop to 21.
Not to speak of all that unpleasant insecticide you'd have to expend.