Some people might not appreciate helpful comments by workers when they’re making big purchases, but it has saved me on a couple of occasions.
When I was stupid enough to put one of those personal air coolers in my shopping cart last month, I was relieved when the cashier told me they were junk and made out of cheap computer fans that aren’t even refreshing at high speed.
They’re basically miniature swamp coolers that fail to accomplish the effects of a real, full-sized swamp cooler. The key issue is the power of the fan, which is often just a cheap computer fan and is not strong enough to move the air required to evaporate the water. If the water doesn’t evaporate, you won’t get a cooling effect from the device. That’s why swamp coolers are usually saved for extremely dry, arid environments with sub 20% humidity indoors. With that much dryness, you can easily get a swamp cooler to work appropriately. Similar to the situation with the air cooler, I nearly purchased epoxy coated rebar one day and an employee told me about the issue with punctures. Apparently epoxy coated rebar fails as soon as a single pin prick makes it through the epoxy layer on the outside. Corrosion happens at a rapid rate because the moisture seeps into the epoxy layer and spreads without any way of drying out. And since you can’t see behind the epoxy, you won’t know where the corrosion is taking place. That’s why I prefer galvanized steel rebar instead, as it has a zinc coating which repels corrosion without the weaknesses associated with epoxy coated steel rebar.