My son's attic is running about ~30 deg hotter than the outside temp in the peak of day and makes the AC work overtime to cool the house. The previous owner re-did the attic/roof, and there are only three vents (on the N, S and West sides) of about 3-4 sqft each. (ie no soffit vents). The home is in southern Arizona where daytime outside temps reach 100-110F. On such days, the home's interior gets to about 85 with AC running 100%, but the attic space hits 135F!. (he has four transducers measuring temperature throughout the 1200 sqft home.) Ive checked all 4 instruments, and they are all reading correct. Even worst, at night once the outside temp drops to a "comfortable" 80F, the attic remains above 100 till morning. I told him he need to add a vent fan to pull the hot air out of the attic; but is there something else he should be looking at doing?

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    It is like sitting in a car with windows closed, it heats up very quickly. Without adequate vents, you may consider creating forced airflow through the HVAC system or add roof deck insulation material.
    – r13
    Aug 3, 2021 at 0:31
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    a gable vent and a ridge/turbine vent would help.
    – dandavis
    Aug 3, 2021 at 0:48
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    The primary protection from attic heat is insulation sitting on the ceiling , although ventilation is always good . Aug 3, 2021 at 1:03
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    Indeed - how much insulation is on the ceiling? Options for moving air are various, and depend on what sorts of things you can or are willing to attach to the roof. The old-fashioned cupola(s), the new-fashioned ridge vent, the presently missing soffit vents, the powered (solar or not) fan vent, the turtle vent(s), the turbine vent(s), the solar chimney(ies)...
    – Ecnerwal
    Aug 3, 2021 at 2:12
  • Thanks all, there is currently about 8-12 inches of blown in insulation sitting above the ceiling in the attic "isolating" the living space. the Roof is roofed with black roofing felt/tiles which certainly dosnt help... Ill try to get some gable vents added and the exhaust fan. I think ridge vents are the best at venting a roof, but they are better added when you build or recover.
    – mark f
    Aug 3, 2021 at 14:47


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