I had work done like this in my house. I just had my house (1927 bungalow, 1092 sq ft) insulated. All the old insulation was removed from my attic. Then all the knob & tube wiring was removed in the entire house and all the wiring was brought up to code. Then, the entire house was air sealed, insulation blown back in the attic and exterior walls. A heat sensor was used to make sure there were no bare spots and the few places that needed additional insulation was topped off. They installed a Panasonic Whisper fan in my small bathroom that is located next to an exterior wall. They used metal ductwork to vent to the outside. Even with my old windows installed I can feel the difference. Plus, my house is so small that removing the moisture/hot air is helping to keep the temperature down a bit. It is 80 degrees outside but my house temperature is cooler...no AC on yet. The bathroom previously had no exhaust fan and I am astonished that, upon taking down old wallpaper, that there was no mold. Whoever designed the house was mindful of airflow, so a big window faces the bathroom shower/tub and the bathroom has two doors on opposite sides. This bathroom is TINY so the airflow must have been pretty good. The guys did good work.
Like the story! With old homes like yours, the walls were typically very leaky, which wasn't great for insulation, but was perfect for drying. Probably the main reason there was no mold in the bathroom walls even with no bath fan. Old houses were very forgiving with moisture since the constant air movement through the walls and ceiling took the moisture with it!
Thanks for the information on bathroom exhaust fans. On placement inside the bathroom, do you recommend installing the fan above the shower/bath (using a fan that's rated for above shower/bath use) or do you install it somewhere else?
We usually layout the fan location to be close to the shower/bath but not directly over it. Often we will locate it between the shower and the toilet but slightly favoring the shower. The bigger key in my opinion is to make sure the exhaust fan flow is adequate. We typically use the 110-150 cfm selectable for owners bathrooms which are typically larger and 80-110 cfm selectable for “normal sized bathrooms that are 5-6 feet wide containing a standard tub/shower unit. Ducting bath fans with solid metal duct and using a low static termination cap are critical for achieving proper (rated) airflow - and testing flow is important. We’ve seen our fair share of bath fan dampers that are pinned closed by a duct screw!
So what is your definition of a short run where you would still use flex duct? 8 foot or less? Also, if you are using flex duct, how would you insulated around it and where it goes out into the soffit? I know some people would use spray foam but doesn't that risk collapsing the flex duct?
8’ or less would be fine with flex duct as long as it is pulled tight. We use raised heel roof trusses and the sheathing goes up over the raised heel to hold the attic insulation over the outside walls so we just cut a round hole through the sheathing and run the vent pipe out through the hole. No sealing needed since it’s outside of our airtight envelope.
@@bambamnj If the bath is on the first floor of a multistory home, it is easiest to take the exhaust fan duct out a sidewall of the building. Using a good quality termination cap with an effective damper will keep cold air from coming back through the duct.
As long as the termination cap directs the exhaust air away, it will not pull the air back into the attic before the moisture is diluted with the outdoor air.
@@AddisonHomes I am glad this question got answered bc I remember seeing one popular home improvement show {thisoldhouse} where they said you should try to never vent through the soffit for exactly the reason the original commend stated and if I remember correctly, they said if you had vent through the soffit you had to make sure your vent dropped down like 8 inches below the soffit. I always thought that was crazy bc I have seen tons of soffit vents for bath exhaust and none of them were dropped below the soffit.
For wall caps, we prefer the Primex WC series wall caps since the have a flange and stand-off that integrates well with water barrier flashing and siding. We use the DewStop condensation fan control with countdown timer.
So many of these little extra efforts make such a difference and so many production builders just don’t do it. As tight as your homes are do you ever use a HRV / ERV for bathroom ventilation and skip the bath fan? I image in some instances its budge related.
No doubt Kevin! The little things can make such a difference! We have used an ERV for bathroom ventilation in the past but discovered that it results in a few challenges: 1) The ERV actually exchanges moisture from the higher moisture air stream to the lower. In this case, we run the risk of "humidifying" the incoming fresh air with the bathroom exhaust air. 2) We discovered that this strategy relies on the homeowner being meticulous with regular maintenance of the ERV (filter changes and cleaning of the cabinet) which frequently is overlooked - which doesn't leave us with a very resilient system for managing humidity sources in the home.
Did not think about the humidity part of the equation, interesting point. The other point is a problem across many homes… unfortunately I find myself helping friends with repairs or fixes that would have been unnecessary if common maintenance had been done! Appreciate your point of view and experience!
@Addison Homes, do you have a particular ERV that you rely on or prefer? We built a home in North Carolina last year, spray foam insulation on first and second floor and sealed attic and crawl space. We are having problems with CO2 buildup in the home, looking at a few options with ERV. Would like to hear your input.
@@LS2FD We currently do not incorporate ERVs as a standard feature primarily due to our experience with lack of maintenance (cleaning) by our clients. Admittedly, I (Todd Usher), don't keep up with the regular cleaning of my ERV at home! With this said, Zehnder appears to be one of the leaders in the ERV industry, but the costs are VERY expensive. Broan and Panasonic make very good ERVs - I personally have a Panasonic in my home. On our new homes, our standard approach for ventilation is to use a ventilating dehumidifier for 1) Fresh air intake, and 2) humidity control of this fresh air and the entire house. I like the Aprilaire EV100 unit with the fresh air adapter since it has onboard controls and will physically draws dedicated fresh air into the system at the prescribed frequency (minutes per hour) which makes it easy to confirm the actual fresh air ventilation flow during ventilation cycles. Here is a marketing video ua-cam.com/video/FkgdbeL2tio/v-deo.html This segment will continue to evolve with new technology and smarter products. Ultraire makes great dehumidifiers but does not have the dedicated fresh air intake damper nor the level of control sophistication. Hope this helps!
do you have a recommendation for a fan/light combo unit? Damn you guys are in Greer, I am in Sumter! Do you also have any recommendation for building performance companies in this part of the state? My dad was a weatherization specialist and building inspector in Maine for like 20 years so he has me qued in on what 'the right' way is and you guys nail it.
Wow! Hey neighbor! I wish I knew of anyone in your area, but sadly, there aren't many of us in the South! Is there something you're specifically looking for?
What are your thoughts on adding a vent in the door for added venting? Our home is of cinder block construction with little to no interior insulation besides thin “studs” with plywood over it. We found this out afterwards. We fight mold in bathroom on outside wall above window. We did replace the old window last year, possibly causing even more condensation
It sounds like you might have condensation occuring on the inside of the walls due to the limited insulation on the concrete block construction. If you check out our video on Basement Wall Insulation Done Wrong, the same concepts likely apply to your wall construction. In this case, the ventilation my not be the issue, but air leakage carrying moisture towards the block resulting in condenstion.
@@AddisonHomes Thanks for the reply, I will check it out. I did want clarify though that when I said "outside wall" I meant the interior wall that the window was in, not the other interior walls of the bathroom. I was not sure if that changed the possible cause.
@@LeeRalph100 That would make sense - the wall between the bathroom and the exterior of the house (where the window is located), if cinder block with poor insulation, would be a classic location for condensation to occur which would lead to mold. Where are you located?
if youre fighting mold on porous surfaces like concrete your problem will continue to arise no matter how much you ventilate. you need to dehumidify and also treate the concrete with antimicrobial products. i just recently remediated a rampant black mold problem in my parents home and learned alot from the mold inspector. invest in a hepa 500 air scrubber and buy a dehumidifier. quarantine the affected area with plastic and be mindful about particulates and where the travel. this is why remediators where tyvek suits. be sure to use proper resperation. antimicrobial paint like kilz over concrete is your best friend and using products like ec3 are expensive but worth it. its the most important work youll do in your home these toxins kill and can cause a very serious set of auto immune diseases. take care and god bless.
If you have two vents in a large custom shower, can the venting be joined to one, then directed away? Or does each vent need to have its own separate run….
Short answer is that each should have its own run, otherwise they will fight each other and could Backflow. Theoretically, you could combine them using a larger duct after they combine along with Backflow dampers to prevent Backflow, but far easier to pipe them separately.
@@AddisonHomes I have been told to never vent through a soffit if it can be avoided. Adding humidity into the soffit area is asking for moisture damage. Additionally, if the attic is vented through the soffit, then you are sucking back in that moist air into the attic.
You didn’t address placement of the fan and orientation with regards to make up air. You want the fan to draw makeup air across the shower/toilet ideally
With a relatively tightly constructed building, placement of the fan isn't super-critical, but we always like to locate it closer to the shower. If the toilet is in a separate room, we always use a second fan. Makeup air is not an issue even in a very tight building.
As long as the exhaust fan is in the bathroom where the source of the moisture is located, it will create negative pressure and remove the moisture. Check local codes if you plan to install the exhaust fan directly over a wet location such as a tub/shower as it should be wired on a gfci (ground fault) circuit.
Love your mindset, just cuz its code doesn't mean its the best
Code is minimum.
I had work done like this in my house. I just had my house (1927 bungalow, 1092 sq ft) insulated. All the old insulation was removed from my attic. Then all the knob & tube wiring was removed in the entire house and all the wiring was brought up to code. Then, the entire house was air sealed, insulation blown back in the attic and exterior walls. A heat sensor was used to make sure there were no bare spots and the few places that needed additional insulation was topped off. They installed a Panasonic Whisper fan in my small bathroom that is located next to an exterior wall. They used metal ductwork to vent to the outside. Even with my old windows installed I can feel the difference. Plus, my house is so small that removing the moisture/hot air is helping to keep the temperature down a bit. It is 80 degrees outside but my house temperature is cooler...no AC on yet. The bathroom previously had no exhaust fan and I am astonished that, upon taking down old wallpaper, that there was no mold. Whoever designed the house was mindful of airflow, so a big window faces the bathroom shower/tub and the bathroom has two doors on opposite sides. This bathroom is TINY so the airflow must have been pretty good. The guys did good work.
Like the story! With old homes like yours, the walls were typically very leaky, which wasn't great for insulation, but was perfect for drying. Probably the main reason there was no mold in the bathroom walls even with no bath fan. Old houses were very forgiving with moisture since the constant air movement through the walls and ceiling took the moisture with it!
Great information! Builder here in Raleigh!
Glad it was helpful! Thanks for the comment - we are working hard to share what we've learned!
Thanks for the information on bathroom exhaust fans. On placement inside the bathroom, do you recommend installing the fan above the shower/bath (using a fan that's rated for above shower/bath use) or do you install it somewhere else?
We usually layout the fan location to be close to the shower/bath but not directly over it. Often we will locate it between the shower and the toilet but slightly favoring the shower. The bigger key in my opinion is to make sure the exhaust fan flow is adequate. We typically use the 110-150 cfm selectable for owners bathrooms which are typically larger and 80-110 cfm selectable for “normal sized bathrooms that are 5-6 feet wide containing a standard tub/shower unit. Ducting bath fans with solid metal duct and using a low static termination cap are critical for achieving proper (rated) airflow - and testing flow is important. We’ve seen our fair share of bath fan dampers that are pinned closed by a duct screw!
@@AddisonHomes Thanks for the explanation! If we got a dollar every time a contractor put a fastener in the wrong place we’d be rich lol.
So what is your definition of a short run where you would still use flex duct? 8 foot or less?
Also, if you are using flex duct, how would you insulated around it and where it goes out into the soffit? I know some people would use spray foam but doesn't that risk collapsing the flex duct?
8’ or less would be fine with flex duct as long as it is pulled tight. We use raised heel roof trusses and the sheathing goes up over the raised heel to hold the attic insulation over the outside walls so we just cut a round hole through the sheathing and run the vent pipe out through the hole. No sealing needed since it’s outside of our airtight envelope.
@@AddisonHomes OK but what if the bath is on the first floor? Shouldn't I be concerned with letting that cold air into the ceiling?
@@bambamnj If the bath is on the first floor of a multistory home, it is easiest to take the exhaust fan duct out a sidewall of the building. Using a good quality termination cap with an effective damper will keep cold air from coming back through the duct.
That second floor fan exhausts at the soffet? Won't the soffit intake just pull all that moisture into the attic ?
As long as the termination cap directs the exhaust air away, it will not pull the air back into the attic before the moisture is diluted with the outdoor air.
@@AddisonHomes I am glad this question got answered bc I remember seeing one popular home improvement show {thisoldhouse} where they said you should try to never vent through the soffit for exactly the reason the original commend stated and if I remember correctly, they said if you had vent through the soffit you had to make sure your vent dropped down like 8 inches below the soffit. I always thought that was crazy bc I have seen tons of soffit vents for bath exhaust and none of them were dropped below the soffit.
Great video! What vent cap do you like to use for wall exits? And what humidity sensing switch do you use?
For wall caps, we prefer the Primex WC series wall caps since the have a flange and stand-off that integrates well with water barrier flashing and siding. We use the DewStop condensation fan control with countdown timer.
What is the make and model of that fan?
We typically use Panasonic LPBFV1115VQ1 or LPBFV0515VQ1
What is the best way to seal and insulate the rigid pipe ?
Either install it low so it can be buried in insulation, or wrap it with duct insulation.
So many of these little extra efforts make such a difference and so many production builders just don’t do it. As tight as your homes are do you ever use a HRV / ERV for bathroom ventilation and skip the bath fan? I image in some instances its budge related.
No doubt Kevin! The little things can make such a difference!
We have used an ERV for bathroom ventilation in the past but discovered that it results in a few challenges: 1) The ERV actually exchanges moisture from the higher moisture air stream to the lower. In this case, we run the risk of "humidifying" the incoming fresh air with the bathroom exhaust air. 2) We discovered that this strategy relies on the homeowner being meticulous with regular maintenance of the ERV (filter changes and cleaning of the cabinet) which frequently is overlooked - which doesn't leave us with a very resilient system for managing humidity sources in the home.
Did not think about the humidity part of the equation, interesting point. The other point is a problem across many homes… unfortunately I find myself helping friends with repairs or fixes that would have been unnecessary if common maintenance had been done! Appreciate your point of view and experience!
@Addison Homes, do you have a particular ERV that you rely on or prefer? We built a home in North Carolina last year, spray foam insulation on first and second floor and sealed attic and crawl space. We are having problems with CO2 buildup in the home, looking at a few options with ERV. Would like to hear your input.
@@LS2FD We currently do not incorporate ERVs as a standard feature primarily due to our experience with lack of maintenance (cleaning) by our clients. Admittedly, I (Todd Usher), don't keep up with the regular cleaning of my ERV at home! With this said, Zehnder appears to be one of the leaders in the ERV industry, but the costs are VERY expensive. Broan and Panasonic make very good ERVs - I personally have a Panasonic in my home. On our new homes, our standard approach for ventilation is to use a ventilating dehumidifier for 1) Fresh air intake, and 2) humidity control of this fresh air and the entire house. I like the Aprilaire EV100 unit with the fresh air adapter since it has onboard controls and will physically draws dedicated fresh air into the system at the prescribed frequency (minutes per hour) which makes it easy to confirm the actual fresh air ventilation flow during ventilation cycles. Here is a marketing video ua-cam.com/video/FkgdbeL2tio/v-deo.html
This segment will continue to evolve with new technology and smarter products. Ultraire makes great dehumidifiers but does not have the dedicated fresh air intake damper nor the level of control sophistication.
Hope this helps!
@@AddisonHomes is the Panasonic fan the absolutely best bathroom fans on the market?
do you have a recommendation for a fan/light combo unit?
Damn you guys are in Greer, I am in Sumter! Do you also have any recommendation for building performance companies in this part of the state? My dad was a weatherization specialist and building inspector in Maine for like 20 years so he has me qued in on what 'the right' way is and you guys nail it.
Wow! Hey neighbor! I wish I knew of anyone in your area, but sadly, there aren't many of us in the South! Is there something you're specifically looking for?
What are your thoughts on adding a vent in the door for added venting? Our home is of cinder block construction with little to no interior insulation besides thin “studs” with plywood over it. We found this out afterwards. We fight mold in bathroom on outside wall above window. We did replace the old window last year, possibly causing even more condensation
It sounds like you might have condensation occuring on the inside of the walls due to the limited insulation on the concrete block construction. If you check out our video on Basement Wall Insulation Done Wrong, the same concepts likely apply to your wall construction. In this case, the ventilation my not be the issue, but air leakage carrying moisture towards the block resulting in condenstion.
@@AddisonHomes Thanks for the reply, I will check it out. I did want clarify though that when I said "outside wall" I meant the interior wall that the window was in, not the other interior walls of the bathroom. I was not sure if that changed the possible cause.
@@LeeRalph100 That would make sense - the wall between the bathroom and the exterior of the house (where the window is located), if cinder block with poor insulation, would be a classic location for condensation to occur which would lead to mold. Where are you located?
@@AddisonHomes In the Mid West
if youre fighting mold on porous surfaces like concrete your problem will continue to arise no matter how much you ventilate. you need to dehumidify and also treate the concrete with antimicrobial products. i just recently remediated a rampant black mold problem in my parents home and learned alot from the mold inspector. invest in a hepa 500 air scrubber and buy a dehumidifier. quarantine the affected area with plastic and be mindful about particulates and where the travel. this is why remediators where tyvek suits. be sure to use proper resperation. antimicrobial paint like kilz over concrete is your best friend and using products like ec3 are expensive but worth it. its the most important work youll do in your home these toxins kill and can cause a very serious set of auto immune diseases. take care and god bless.
If you have two vents in a large custom shower, can the venting be joined to one, then directed away? Or does each vent need to have its own separate run….
Short answer is that each should have its own run, otherwise they will fight each other and could Backflow. Theoretically, you could combine them using a larger duct after they combine along with Backflow dampers to prevent Backflow, but far easier to pipe them separately.
You opinion on "Roberts Roof Cap"
@@citylockapolytechnikeyllcc7936 looks like a good product!
Is it more efficient to go horizontal through the side of the house vs. vertical through the roof?
Depends on where the bath fan is located but we typically prefer a sidewall or soffit termination over a roof termination.
@@AddisonHomes I have been told to never vent through a soffit if it can be avoided. Adding humidity into the soffit area is asking for moisture damage. Additionally, if the attic is vented through the soffit, then you are sucking back in that moist air into the attic.
What pipe size are you using, 6 or 4-inch?
We use both 4" and 6" depending on the bath fan model. The 110-130-150 cfm fan uses a 6" diameter vent pipe
Panasonic is the way to go
Does the fan have to be on a GFCI?
Check your local code, but if mounted directly above a shower or tub, it typically does.
I flex anytime I do work on the house.😂
You didn’t address placement of the fan and orientation with regards to make up air. You want the fan to draw makeup air across the shower/toilet ideally
With a relatively tightly constructed building, placement of the fan isn't super-critical, but we always like to locate it closer to the shower. If the toilet is in a separate room, we always use a second fan. Makeup air is not an issue even in a very tight building.
1.5x...
Nothing about placement?
As long as the exhaust fan is in the bathroom where the source of the moisture is located, it will create negative pressure and remove the moisture. Check local codes if you plan to install the exhaust fan directly over a wet location such as a tub/shower as it should be wired on a gfci (ground fault) circuit.