We open our window at night at the temps get down to 70F @20% RH. The temp in the house drops to 75F and the RH is 33%. We close our windows when we go to work.
When mid day comes, outside, the temp is 95F and the RH is 10%. Inside the temp is 76F and RH is 40%. How is this possible?
- we have no water leaking into the house... with water off... usage is 0.
- Cement slab.
- Nobody is home. We have a couple dogs but they can't contribute that much water.
- There is a temperature difference in the house one side is 74F and another side of the house is 78F.
- We are waiting on a manual J to be completed, the guy thinks our AC is oversized. But that explains why moisture isn't leaving. But it doesn't explain where the moisture came from to begin with.
- We had a pressure test done on the house... -0.1 pascals. So we are in good shape there.
- It seems to me the only way water could get in, if no leaks, is condensation some where. The air handler is in the attic, attic get hot during the day...
In most building calculations... if we recycled 60% or our air and used 40% from outside at 95F at 10% humidity, we would have to add a quart of water every hour to the air to MAINTAIN 40% RH. THIS IS NUTS!!!! So much for the idea that we are breathing air through a leak... as a problem.