Tenant complaining about HVAC

[Sohil Shah]

I have a tenant complaining that the AC is not cooling when the temperature get around 90 degrees but it cools in the morning and the evening when the temperature is lower and also the walls are sweating for some reason. (I don't know why this is happening) 

I went into the unit today to check the insulation in the attic and the crawl space it looks good to me and the house was cool when I went in there around 10:30am. 

How do i tell the tenant that the HVAC is working and there are no issues found? or can it be something else that i overlooked?

[Joshua Ferrari]

Too many variables to be able to give a definitive answer. Is this an older home? I've got a fourplex that's 100 years old and my tenants that live upstairs complain about the heat during the day in the middle of the summer. My solution was to get black out curtains for the windows to keep the suns heat out and buy them a window unit. 

The central HVAC just can't keep up with the extreme heat down here with such a lack of proper insulation in the windows and walls. During the morning and night though, they are plenty cool. It's just during the day, and now that everyone is working from home due to COVID-19, I felt it necessary to buy the curtains and window units.