ctviggen
Well-Known Member
We have two small bathrooms that are side by side. One is a 1/2 bath, one is a full (but small) bath. I bought two 50cfm fans for them (in 2015- they are older). We had the ducting installed, and they connected both together and the output went to a soffit. We had the problem that when someone took a shower in the full bath, humidity came into the 1/2 bath. So, we had the ducting split to two soffit vents.
We have someone using the full bath. Within minutes of turning on the shower, it gets moist and the glass fogs up. The fan is working. This is in an in law apartment we're renting, so I only have access when she's there.
I went to the 1/2 bath (in our main house) and I tested the fan suction by using paper that got sucked up against the fan. I then went outside and took off the soffit vent. I tested the fan again using the paper trick. It SEEMED like the paper was on there stronger, but it's difficult to know.
My theory is that the soffit vent they used is restricting flow. I could get a better soffit vent. But I can't figure out how to test (in the 1/2 bath) that the soffit vent is restricting flow.
Is there any way to perform a better test of a bathroom fan?
(I will ask the renter to get in there, take off the soffit vent, turn on the shower, and see what happens. But I'd like to see if the soffit vent is an issue, and replacing a fan is harder, because I have to figure out the volume of the bathroom, the length and type of ducting for 4 inch ducting, etc., to ensure the fan and ducting are suitable.)
We have someone using the full bath. Within minutes of turning on the shower, it gets moist and the glass fogs up. The fan is working. This is in an in law apartment we're renting, so I only have access when she's there.
I went to the 1/2 bath (in our main house) and I tested the fan suction by using paper that got sucked up against the fan. I then went outside and took off the soffit vent. I tested the fan again using the paper trick. It SEEMED like the paper was on there stronger, but it's difficult to know.
My theory is that the soffit vent they used is restricting flow. I could get a better soffit vent. But I can't figure out how to test (in the 1/2 bath) that the soffit vent is restricting flow.
Is there any way to perform a better test of a bathroom fan?
(I will ask the renter to get in there, take off the soffit vent, turn on the shower, and see what happens. But I'd like to see if the soffit vent is an issue, and replacing a fan is harder, because I have to figure out the volume of the bathroom, the length and type of ducting for 4 inch ducting, etc., to ensure the fan and ducting are suitable.)