My sister’s cat is congesting my air filter

I’m genuinely not an animal person. My sister likes cats, plus that is why I allow any sort of animal into my house. Even though there’s only one cat allowed in this house, I can feel the irritation that boils in my heart whenever she brings her cat over. It strives to make me angry! Every time, the cat hogs the vents to my Heating plus Air Conditioning units, which is horrible for many reasons. One reason that I don’t adore it when the cat sits on top of my vents for the oil furnace plus the a/c is because he completely hogs the conditioned air. This is especially noticeable when it’s winter and the heat is more necessary than the cool air in the Summer. The animal will sit directly on top of my Heating plus Air Conditioning vents, plus after a few hours, I can feel the difference in the room that I’m trying to keep cool. No matter how many times I transport the animal off of my vents for the oil furnace, he consistently lays back on it. Lately, I have had to spitz the animal with water just to get him off my vents so that I can properly heat my home with my oil furnace. However, there’s another problem with my sister’s animal kneeling on the vent. As he sits there, pet hair plus dander begin to get dispersed around my house, plus it completely ruins my air filter in our Heating plus Air Conditioning systems. This could potentially ruin my Heating plus Air Conditioning units, plus it also causes me to sneeze frequently.
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