DIY fail: Operation Cool(er) Catio

Usually my DIY projects mostly turn out how I expect them to. But not always.

The Problem

It gets hot in Texas; no surprise there. My patio has high walls and is shaded inside, but the outside walls get direct sunlight all day. There are also some air conditioning units next to one wall and occasionally I can feel the hot air they are expelling blow in through the slats in the fence on that side. I’ve put in a lot of work to make the patio/catio one for both Willow and myself to enjoy, and I want to be able to! But it’s too darn hot.

The Hypothesis

So I had an idea: What if I could line the walls with something that would reflect the heat outwards, away from my patio? I ordered some emergency blankets from Amazon, the kind that have a reflective side that is supposed to reflect 90% of heat. Several of the reviews mentioned using the blankets for the purpose I had in mind. Why I bought these particular blankets was because of the color on the reverse side: I didn’t want my patio walls to be bright orange or green. My theory was that the emergency blankets would reflect enough of the heat outwards to make the patio noticeably cooler.

The Experiment

Before I put up the blankets, I monitored the temperature on the patio for a week using an outdoor thermometer. Because my patio fence gets direct sunlight all day, and also faces the car park and the heat that is reflected off of the asphalt, I suspected that it might be hotter on my patio than the temperature reported on my Wunderground Weather app. To my surprise, the temperature on the patio was consistently one to two degrees cooler (Fahrenheit) than the temperature reported by my app. That the interior of my patio is shaded has an effect after all.

patio emergency blanket wall

It isn’t pretty, but I’d put up with it if it worked.*

We had a heat advisory forecast for this weekend and I wanted to put the emergency blankets to the test. I put the blankets up on two of the three exterior walls (only two, because I ran out of staples for my staple gun), and frequently compared the patio thermometer with my weather app.

The Result

Well, my theory proved to be false:

Since putting up the emergency blankets, the temperature on the patio has been consistently a few degrees higher than the temperature reported by my weather app. I will be taking the blankets down once it gets cooler later in the evening.

The Conclusion

One reason the experiment failed, I think, is that it reduced the air flow in the patio. Although the patio is fenced in on three sides, it’s a wood fence with small gaps between the slats that can get a good cross breeze depending on the direction the wind is blowing. I had hoped to counteract the blankets’ reduction of air flow by opening up the bottom of the fence (it had been closed off with bricks, which I replaced with a lattice**) in order to have the convection effect from allowing air flow below and above the fence. I don’t know if the effect actually occurred (as it was too hot for personal observation), but even if it did, it wasn’t enough to cool the patio.

Obviously, this wasn’t a very scientific experiment. I didn’t explore or account for all the variables. But at least it was empirical, right?

Now I’m back to the drawing board for Operation Cool(er) Catio. I’d really like to be able to make the patio a bit cooler for the sake of myself, my cat, and my plants! I already have a few plants that have succumbed to the Texas heat and would prefer to not lose any more of them.

Do you have any suggestions? Leave a note in the comments if you do!


*  You’re getting a sneak peek of one part of the catio. I’ll write more about the catio in a later post!
** Else Miss Adventure Paws, a.k.a. Willow, would escape.