Basement bathroom fan/vent near ceiling hot air register ?

I have a small bathroom in the basement, which has no fan.. The only place open enough to install a fan, and ducting is between the same joists that already has a furnace register. How close can I position the fan and the register ? Everything is tight because of lights, plumbing, wiring etc.. Thanks
Ray
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'd want them as far apart as possible, at least 5 ft. If they are close then you'll just wind up pulling air from the HVAC instead of the bathroom when the HVAC is running. Two problems with that. Loss of energy and not pulling the air you want to remove from the bathroom. In addition to positioning the new fan, consider the possibility of moving the HVAC register.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'd want them as far apart as possible, at least 5 ft. If they are close then you'll just wind up pulling air from the HVAC instead of the bathroom when the HVAC is running. Two problems with that. Loss of energy and not pulling the air you want to remove from the bathroom. In addition to positioning the new fan, consider the possibility of moving the HVAC register.
Trouble is the bathroom is only 5 feet deep in the direction the joists go. Probably get 3 feet of separation..
Looks like either this close or no vent.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Is there a shower?
No vent could mean mold, peeling paint or both.
Consider a powered damper upstream in the furnace duct someplace.
As an example, this site has normally open dampers that would closed when powered is applied.
http://www.discount-hydro.com/electric-duct-dampers /
The same switch that turns on the fan could apply power to the damper closing it while the fan was in use.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Is there a shower?
No vent could mean mold, peeling paint or both.
Consider a powered damper upstream in the furnace duct someplace.
As an example, this site has normally open dampers that would closed when powered is applied.
http://www.discount-hydro.com/electric-duct-dampers /
The same switch that turns on the fan could apply power to the damper closing it while the fan was in use.
Thanks... Looks like a good idea... Too bad that site only has as small as 6" dampers, when the furnace duct is 5" I guess I could adapt down.. I'll search around for other similar dampers
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If there are no other simple alternatives, that might be good enough. You can make sure the air from the register is directed away from the exhaust fan. The HVAC typically runs only a small percentage of the time, so the potential conflict won't be there all the time. And if the conflict does exist, then it means either the AC or heat is running. Either of those will help vent the bathroom as well after the fan shuts off.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If there are no other simple alternatives, that might be good enough. You can make sure the air from the register is directed away from the exhaust fan. The HVAC typically runs only a small percentage of the time, so the potential conflict won't be there all the time. And if the conflict does exist, then it means either the AC or heat is running. Either of those will help vent the bathroom as well after the fan shuts off.
I returned the fan I bought to HD, and bought a smaller fan with a 3" outlet It says ok to install over the bathtub in the ceiling drop, so a better location
I will with difficulty be able to work a 3" duct through the pipes and wires. only about 3 feet from the outside wall, so shouldnt be that much resistance to air flow
Thanks for all the advice..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.