Wondering if it makes economic sence to replace a bathroom exhaust fan
Since buying our home 10 years ago, we've replaced all the major appliances, including the lovely avocado green fridge in our tenant's apartment. I've been wondering if there's anything else should be replaced for energy savings.
We have two bathroom exhaust fans. One is our main bathroom and the other is in our tenant's bathroom (lower level).
For years we were confused about our tenant's exhaust fan because we couldn't figure out where the air was coming out. Another mystery was why on the east side of the house there was a second vent, right next to the dryer vent. Turns out that vent does belong to the basement bathroom vent but we couldn't believe it.
The bathroom is against the west side of the house, the bathroom exhaust duct work runs 24',between two joists & across the width of the house until it hits the east wall, makes a 90 degree bend, runs straight for roughly 5', and then makes another 90 degree bend to the outside. Which means that the exhaust vent is pushing air 29' with two 90 degree bends. Because this is a bathroom in a half basement (grade is at roughly 3.5') with no windows, the tenants run the exhaust fan a lot. Remarkably there's no mildew problems.
The exhaust fan looks oldish - I'm going to guess by the styling maybe from the 80s. I can feel air when I put my hand on the outside vent so I know it is doing its job but I'm not sure how well.
I'm wondering if we should replace our tenant's bathroom fan. Our bathroom exhaust fan upstairs is probably pretty old too but since we don't use it often, I don't think it makes economical sense to replace it. The basement bathroom exhaust fan, however, runs for much longer times and I think is more critical to the health & well being of our tenants.
On one hand, if it's not broke, don't fix it. On the other hand, I wonder if I should replace it for energy/economic savings.
And a quick additional question: is it unusual to have such a long route from the exhaust fan to the outside vent? This house was built in '67 and most the time the builder took shortcuts (for example, originally the upstairs bathroom & kitchen exhaust emptied directly into the attic) and so we're surprised that they put in such a long bit of duct work.