Should we replace broken solar powered attic vents?
We live in hawaii. Temps are 80-90 daytime and 65-72 nighttime. We like the house around 78. Only run a/c maybe 45 days a year. 4000 sq ft house with tile roof, continuous soffit vents and 6 inch batting insulation. We have 4 broken solar powered attic vents installed on the roof now. We have a solar pv system with extra capacity so power is essentially free.
Let me first turn this around - what made you notice that they were broken? Was it because of an issue, or did you just happen to be up there and go - wow this isn't one isn't moving and wow none of the others are either?
For 95% of the homes I have seen, especially with a tile roof (which essentialy blocks radiant heat transfer & has its own venting) there isn't a need for "assisted" ventilation.
Might the attic be a fraction cooler with them - sometimes.
Where are your ducts located? If they are in the attic, the ventilators might help some, but it would probably be better to make sure they are well sealed & insulated.
Will it save you the $1600+ to replace them - not even close especially when you only need the AC 45 days a year.
For more information:
Read "How effective are the different attic ventilation methods? I read mixed reviews, and many have a commercial bias." a Q&A answered by Danny Kelly.