I thought that if you install any kind of fan you gotta make sure you have adequate intake or soffet venting because the fan will create a negative pressure and unless your attic is 100% air sealed from the interior, will pull out conditioned air from the home.. or create a positive pressure if using a fan as an intake and will push the hot air into the home...
If your attic floor isn’t air sealed well, you could create pressurization issues in the home. I see it often during my building science investigations. Otherwise, they seem to be nifty little tools. If you’re going to get one installed, maybe mix it with having the contractor make sure the building envelope from the attic plane is sealed.
I had a wet low spot in front of a high drain. I put a sump pump with sump pit in and a 40 ft long (maybe longer)french drain on the low wall. I attached a 25 foot pump hose and ran it out the house drain. In addition to that I added a GFCI electrical outlet and ran an extension cord from the sump pit area along the floor joist to a position about 20 feet uphill in the crawl space. I bought a $20.00 box fan and put it on a couple of Breeko blocks. I hooked it up to the extension cord overhead making sure no electrical could touch the ground. I change the box fan every couple of years at the Home Depot and use the fan somewhere else where I can monitor it or get rid of it. I also put Breeko blocks around the sump pit to drain area and run a small heater inside the Breeko blocks. It is fire proof, It sits off of the crawl space floor and the Breeko blocks keep the heater off of the floor. It is also plugged into the GFCI outlet. Works like a champ.
I just found your videos when looking to install a radiant barrier in my attic. How much difference does adding whisper fan vs just radiant barrier? I currently have white metal roof, solar vent, and two small gable vents.
Another option would be to install soffit and ridge vents if you dont have them. And a feebie would be to make sure they are not blocked, very seldom are there enough vents, much less if blocked.
Thanks Michael, very informativo. I have a question about cooling an attic that has two gable openings one in front of the other. Front and back of the house. My idea is to install a gable fan to exhaust hot air and another to blow cool air from the outside. All gable fans seem to be just to be exhausting? Which one is the one to blow air in? Or all is needed is to turn the fan? Your expert advice would be greatly appreciated
I had a house with 2 gables. I sealed them because they were allowing rain to enter and causing mold around them. After I sealed them I made sure the baffles kept the soffits clear and the ridge vent was good and I installed a solar attic fan. Made a huge difference. I say all of that because installing gable fans may cause a moisture problems. Usually, one is sufficient blowing out. But that depends on attic size. Do you have a local roofer/weatherization contractor you could have take a look? Hope that helps.
Thanks Michael for all this really useful videos on the crawl space and attics! It has really helped me to understand good options for solving problems I am encountering on my new home! I am following your good advice on sump pumps and attic fans! I installed a gable fan and it helps a lot. Thanks.
When installing baffles that run to the ridge vent, am I correct in thinking that a soffit vent should be between each rafter. I'm finishing a room above a garage and plan to insulate.
No theres actually a ratio of the amount of soffett to gable or ridge vent so you dont start exhausting air through the soffett or sucking in air fton the gable or ridge vents.. same aspect as if you installed a gable fan right next to a ridge vent. They would cancel eachother out just cycling air within that space being close together. Im pretty sure a soffet vent every 10 feet is adequate allowing a baffle or gap between the soffett vent and attic not covered up with insulation. And a gable vent for every 500 sq ft of space.. ridge vent specs are different but are listed on tge packaging.. but with soffett vents just make sure to install a baffle or insulation dam to create a place for the air in the attic to vent through that soffett vent. Good way to tell is to go in the attic and turnout the lights and should be able to see daylight at each soffett vent.. if not then it needs a baffle installed at every vent...
Brad - Now if your question is mostly is the fiberglass blowing around going to be an issue, I would say no because pretty much it settles down. I don’t think it’s going to get too airborne and if it does, it’ll just get blown out the vent.
We just turned part of 4 season porch into a bedroom. I insulated the attic space above pretty well with blown-in fiberglass. The house is old and doesn't have soffit vents so I did not install baffles. There is only one box vent on the roof so some roofers suggested adding a gable vent. They didn't seemed concerned about not having soffit vents. He believes having the gable vent should be enough. I thought for a gable to work you need it on both sides of the attic. perhaps the box vent and gable vent will work together to cool and draw air into and out of the attic?.... I live in a very cold climate
In TN, we have ridge and soffit vents and when we did attics, I liked adding an active ventilation, typically solar so only ran during day. Let us know if your design is ventilating enough.
@@CrawlSpaceNinja I'll have to report back once I finally get around to cutting access and adding a gable vent. I realize ventilation is important, but in MN I'm much more concerned about keeping heat in the majority of the year.
It is possible to use your AC unit and your fan simultaneously. You shouldn't turn on your air conditioning system if the outdoor air is cooler than the indoor air.
Michael, I have a cape cod house with a double-ridge pole running the length of the house. I believe that there is not enough opening in the ridge to allow the air to escape. The standard maximum opening for a ridge vent is 3 1/4" and if you add 2 - 1 1/2" ridge poles, that only leaves 1/4" gap total (1/8" on each side of the roof). My roof pitch is 9:12. Is there an extra wide ridge vent made that would allow me to cut more of my roof out to have proper ventilation? Thanks
I am so sorry I don't have an answer. Are there any roofers watching that could help answer that? Have you contacted local roof/insulation supply store?
Michael, thank you for the videos. I watch and learn. For the “whisper” fan, you had it installed high in the attic and exhausted into the soffit? I have mold on the north facing side of my roof sheathing and have pulled my hair out to address the challenge (mid Atlantic area). Could this be my next attempt to fix my issue?
I put a common box fan ( mounted horizontally) .... right under the "peak" of my attic roof, using 2x4 supports, blowing "up" toward/out the ridge vent above. Note....I have eaves / soffits with open holes providing the incoming air, so I am not creating a preferred path sucking from the air-conditioned living space.
I bought a old house (renovated) that doesn’t have soffit vent on them but has sliding windows on the side where it used to be gabble vents before. I’m having problem with minor mold growing in the back of roof during winter. I installed a window fan for temporary fix to exhaust heat and bring fresh air to my attic. So the question is, should I install roof vents ventilation for the permanent solution?
The air temperature outside is typically lower than air temperature in the attic. Condensation can form whether your attic is ventilated or not if dew point is at a level to cause ducts to condensate. In most cases, bringing in cooler outside air will help keep attic cool. Making sure your ducts are well insulated and not leaking air should decrease chance of condensation in a ventilated or non-ventilated attic. In some instances, regardless of ventilation, a dehumidifier is necessary as well to prevent condensation. Every attic, situation, and climate are different so it may be worth consulting a local professional to address concerns in your area. Thanks for the comment!
My attic has dozens of round soffit vents fitted with a screen mesh. IMO, the square mesh seems pretty wide. Today I had to seal off a small gap that some paper wasps found near some of the vents. I watched them get confused after the gap was sealed, and I've noticed that they don't go into the round vents right next to the gap even though it seems like they could easily pass through the mesh. I've been concerned that they might figure out they can sometime, and that I should probably get a second layer mesh to add behind the existing. It's just that these are very difficult to reach from inside and there are a lot of them. Is there a special reason they don't already enter this way? Maybe I don't need to do anything? I've lived here for years without issues, but I want to be safe.
@@CrawlSpaceNinja turns out they figured out last week that they can get in this way. I ordered some soffit vent mesh screen covers. And I'll be removing whatever they are currently building in the attic now. No fun.
This advice (powered attic vent) seems to go against current building science practices from people like Allison Bailes, Matt Risinger, Joe Lstiburek, Martin Holladay, and Fine Home Building, among others. Is this advice for a particular situation or climate? I thought the main consideration of venting the attic was moisture control. What about air sealing and insulation considerations? Thanks. I enjoy your video’s but this one confused me.
First step is to keep the heat out. If you can avoid the attic from heating, that is always the better move. But once the heat is in the house, and in the night it is cooler outdoors, nighttime ventilation is definitely a very good move to avoid overheating in the summer. But the control settings need to be tuned to only ventilate when there is cooling demand and when the outdoor temperature is low enough.
We have a ranch style house central NC with a metal roof with a conventional attic with full length soffit and a ridge vent. We also have gable vents at both ends and I have a thermostat controlled power vent in one of the gables blowing out. I have air sealed pretty well in the attic and we have R-49 batt insulation (R-30 one way and R-19 the other way) with the baffles to keep the soffits clear. I have read many differing opinions on what if anything I should do differently. I have seen keep it the way it is or to get rid of the power fan and block off the gable vents leaving only the soffit and ridge vents. Any advice?
Hi Sean, as we talk about in the video, we recommend ventilating the attic. It sounds like you're doing everything right. Are you finding that the rooms below your attic are still uncomfortably hot or cold depending on the season?
A side note from Michael, you should only have 1 type of ventilation, ridge or gable. Not sure which journal, maybe JLC, there was a test if you had both, you will lose the benefit of both. They kind of cancel themselves out. Heat rises so the best one for removing heat is the ridge vent, assuming its of adequate size.
@@CrawlSpaceNinja We don't notice much difference in temperature. The concern was whether the gable vents were reducing the effectiveness of the ridge and soffit system. The other concern was whether the power fan electricity use was more than the energy savings of a cooler attic.
@@SJ-gd6bo That is what I was wondering about having both approaches to ventilation/cooling. It seems like the "belt and suspenders" approach the builder took for attic ventilation might not be better than ridge and soffit alone.
Attic should be vented year round. In the winter if there is no ventilation warm humid air from the living space(shower, cooking, the people inside just breathing) will migrate into the attic and condense on a cold surface…. The roof deck. Also Ice damming can occur in a vented attic assembly if the attic is not as close to the ambient outside temp as possible. In my opinion in a vented assembly: make sure air sealing between living space and attic is done, make sure adequate insulation is present, make sure all appliances are vented outside not dumped in the attic, and make sure your attic is properly ventilated. Several roof vent calculators online. I see this mistake all the time when people put trash bags on their whirley birds. It says on the box Do not cover lol.
You should feel a difference in interior temperature if the outside is cooler than the inside. Attic fans actively move air out of the attic, which makes them a better choice for ventilating the attic. The whole house fan only transfers air from the house to the attic.
@@CrawlSpaceNinja yes the whole house fans do transfer air from house to the attic. but let's not forget early in the summer morning and late in the evening cooler air from outside with doors and windows cracked open transfer that cooler air into the house keeping the inside of the house cooler and less utilization of the Air Conditioning. which is less cost on one's energy bill
Hi Michael, great video. I installed a gable fan in my attic the thermostat stopped working, so I turn it on and off at the switch. I live in the San Fernando Valley in So. Cal. I'm thinking of installing a small Evaporative Cooler on the opposite gable. Any advice? Thanks in advance. { :-€) GBY
Need to research a little more. Understand that soffett vents are at the eves of the roof or bottom of the roof/ attic. Ridge is at the crest of roof.. air goes from bottom to top. Blowing air out of the ridge vent without a soffett venting system will be like having somebody blow at you from across a hot room with no air movement.. you might feel the blow but wouldnt effect anything.. had a buddy install a big ass fan on an attic window he had with only having soffett vents and no gable or ridge venting. When he turned the fan on the first time it blew every bit of blown in fiberglass insulation through that fan into his yard almost where it was sucking the air through the only place it could through what few soffett venting he had.. but is what you should expect putting a 5 foot round industrial turbine fan on an attic window.. he could fumigate the whole house and suck out all of it in a half a minute with that thing.. said if he left the attic hatch open itd close every door it could in the house...
Hi! So I rent the attic space in my house now and it’s been getting in the 80’s outside..I have a thermometer in my room and even at 10-11pm it reads it’s 85 degrees. It’s clearly not insulated because it gets super hot in the summer and freezing in the winter. It may be ok if it was just me, but I have a dog that is sitting in the heat. I tried using AC window units but they seem to overwork and it is too hot for them to work. I don’t know what else I can do to try and keep it cooler.
I am getting ready to build a new house and have been looking at using a roof decking with a foil backing as my radiant barrier. You stated in your video that there needs to be an air gap between the barrier and the roof. Do you feel this foil backed decking is an adequate way to use a radiant barrier or am I wasting my money?
I'm not familiar with that product, so not too sure. I'd recommend reading the install instructions/claims of that product. The radiant barrier we featured must be installed the way we discussed but there are even radiant barrier paints. Unfortunately I am not as familiar with those products either.
I have a double envelope house with a passive solar heating system. It was built in 1980. One feature of this house is that it has two closets on the highest level of the house (on each side) - both containing a couple vents. I believe these are there to allow warm air to leave the house as it rises during the summer. The problem with these vents is that they allow too much cold air in during the winter. When I bought the house, the closets had foam insulation that could be stuffed in the doorway of these closets to help keep the cold air out. But this does not do a good enough job. I'd like to also put some tight-fitting insulation in the vents themselves for extra insulation (I would then remove the insulation in the spring/summer). I'm wondering, can I treat these vents like crawl space vents to insulate or is there a better way? Should I cut a piece of foam insulation to stuff in there? Or fiber insulation? Or both? I feel that my house could be much more energy efficient if I found an effective way to insulate these closet vents. Anyways, being that I am a new homeowner I have enjoyed your videos and have subscribed to your channel!
Hey Stephen Delwiche, Installing temporary insulation in these vents during the winter months would be best practice. Foam insulation would likely be the best solution here. Thanks for watching and have a blessed day
Hi quick question my garage has no ceiling, I'm planning to insulate and put ceiling on. Its a 300sqft. Can I just put window vent on the attic? I live in California
Hi. Is there any reason to put in 4 new passive flush vents on my new roof? I have 3 gable vents, one has a new attic fan and tons of soffit vents. I will be eliminating 3 old half dome style vents when my old roof comes off. Thanks!
There are many theories and opinions of what attic temp is too hot. What I am seeing from most roofers and inspectors is try to keep attic temp within 20 degrees of outside temp. So if it is 90 degrees outside, 110 degrees in attic is great. Keep in mind these are guidelines and in some cases may be impossible to reach without major corrections like radiant barriers, air sealing, etc.
I installed a gable end attic fan this morning. Btw there is currently 1 inch of old cellulose insulation in most of the attic. Yesterday it was 105 outside and 74 inside at 70% humidity outside and 53% inside. Today is the same outside, and 67 inside at 49% humidity. We have no soffit or ridge vents. The gable end vents are 2ft by 3ft each.
My house doesn't have gables and I'm reluctant to install a roof mounted attic fan for fear it will cause leaks. All the eaves around the house are vented. Are there other options you can recommend to increase air flow through the attic?
Yes! I pull the stairs open and leave a 3-4in opening on the bottom of the garage door on a 100 degree day. You will notice the ac being more effective at keeping home at the set temp especially if you have a split hvac system where the other half is in the attic.
Keep your attic door closed unless your home is naturally ventilated and not air-conditioned. If you're in that situation, it may be better to just open the windows on either side of the attic and close the door.
I love all your videos! I wish you were in Texas! We have a second floor attic area above a bedroom that keeps that bedroom extremely hot. We are trying to find a solution. We just had a brand new roof put on. We didn't notice the extreme heat until this Spring. We cut a small area out of the ceiling so we could see what was going on up there. The space is a little insulated, but obviously not enough. I don't think I or my husband could fit up there to take care of the problem. Any suggestions?
Attic ventilation is just as important in cold weather as in hot, if not ventilated correctly for cold weather you will have condensation problem, freezing and thawing causing a problem.
Interesting video. We have soffits in our home and had a ridge vent installed when we built. We haven’t finished our attic space yet (home was built as a cape) so I haven’t had to deal with venting what will be the true attic yet. Good suggestion with the whisper fan.
I thought that if you install any kind of fan you gotta make sure you have adequate intake or soffet venting because the fan will create a negative pressure and unless your attic is 100% air sealed from the interior, will pull out conditioned air from the home.. or create a positive pressure if using a fan as an intake and will push the hot air into the home...
If your attic floor isn’t air sealed well, you could create pressurization issues in the home. I see it often during my building science investigations. Otherwise, they seem to be nifty little tools. If you’re going to get one installed, maybe mix it with having the contractor make sure the building envelope from the attic plane is sealed.
I had a wet low spot in front of a high drain. I put a sump pump with sump pit in and a 40 ft long (maybe longer)french drain on the low wall. I attached a 25 foot pump hose and ran it out the house drain. In addition to that I added a GFCI electrical outlet and ran an extension cord from the sump pit area along the floor joist to a position about 20 feet uphill in the crawl space. I bought a $20.00 box fan and put it on a couple of Breeko blocks. I hooked it up to the extension cord overhead making sure no electrical could touch the ground. I change the box fan every couple of years at the Home Depot and use the fan somewhere else where I can monitor it or get rid of it. I also put Breeko blocks around the sump pit to drain area and run a small heater inside the Breeko blocks. It is fire proof, It sits off of the crawl space floor and the Breeko blocks keep the heater off of the floor. It is also plugged into the GFCI outlet. Works like a champ.
Interesting. Thanks for sharing! Do you find that your humidity stays around 50% with this set up?
I just found your videos when looking to install a radiant barrier in my attic. How much difference does adding whisper fan vs just radiant barrier? I currently have white metal roof, solar vent, and two small gable vents.
Another option would be to install soffit and ridge vents if you dont have them. And a feebie would be to make sure they are not blocked, very seldom are there enough vents, much less if blocked.
That is very true! Thank you.
I have 2 large windows. I covered one of them with bubble foil to block some of the heat on the south end.
Let us know if you found that it helped!
Thanks Michael, very informativo. I have a question about cooling an attic that has two gable openings one in front of the other. Front and back of the house. My idea is to install a gable fan to exhaust hot air and another to blow cool air from the outside. All gable fans seem to be just to be exhausting? Which one is the one to blow air in? Or all is needed is to turn the fan? Your expert advice would be greatly appreciated
I had a house with 2 gables. I sealed them because they were allowing rain to enter and causing mold around them. After I sealed them I made sure the baffles kept the soffits clear and the ridge vent was good and I installed a solar attic fan. Made a huge difference. I say all of that because installing gable fans may cause a moisture problems. Usually, one is sufficient blowing out. But that depends on attic size. Do you have a local roofer/weatherization contractor you could have take a look? Hope that helps.
I have gable vent, soffit vents, and long ridge vent. Should i block off the gable vent?
Thanks Michael for all this really useful videos on the crawl space and attics! It has really helped me to understand good options for solving problems I am encountering on my new home! I am following your good advice on sump pumps and attic fans! I installed a gable fan and it helps a lot. Thanks.
I'm so glad you found it helpful. Thank you for your support!
When installing baffles that run to the ridge vent, am I correct in thinking that a soffit vent should be between each rafter. I'm finishing a room above a garage and plan to insulate.
No theres actually a ratio of the amount of soffett to gable or ridge vent so you dont start exhausting air through the soffett or sucking in air fton the gable or ridge vents.. same aspect as if you installed a gable fan right next to a ridge vent. They would cancel eachother out just cycling air within that space being close together. Im pretty sure a soffet vent every 10 feet is adequate allowing a baffle or gap between the soffett vent and attic not covered up with insulation. And a gable vent for every 500 sq ft of space.. ridge vent specs are different but are listed on tge packaging.. but with soffett vents just make sure to install a baffle or insulation dam to create a place for the air in the attic to vent through that soffett vent. Good way to tell is to go in the attic and turnout the lights and should be able to see daylight at each soffett vent.. if not then it needs a baffle installed at every vent...
what about insulation? Will the fans blow that around?
Brad - Now if your question is mostly is the fiberglass blowing around going to be an issue, I would say no because pretty much it settles down. I don’t think it’s going to get too airborne and if it does, it’ll just get blown out the vent.
We just turned part of 4 season porch into a bedroom. I insulated the attic space above pretty well with blown-in fiberglass. The house is old and doesn't have soffit vents so I did not install baffles. There is only one box vent on the roof so some roofers suggested adding a gable vent. They didn't seemed concerned about not having soffit vents. He believes having the gable vent should be enough. I thought for a gable to work you need it on both sides of the attic. perhaps the box vent and gable vent will work together to cool and draw air into and out of the attic?.... I live in a very cold climate
In TN, we have ridge and soffit vents and when we did attics, I liked adding an active ventilation, typically solar so only ran during day. Let us know if your design is ventilating enough.
@@CrawlSpaceNinja I'll have to report back once I finally get around to cutting access and adding a gable vent. I realize ventilation is important, but in MN I'm much more concerned about keeping heat in the majority of the year.
Can I use my attic fan at the same time as my cantral air?
It is possible to use your AC unit and your fan simultaneously. You shouldn't turn on your air conditioning system if the outdoor air is cooler than the indoor air.
Informative. Just got new roof keeping attic very important
Absolutely! Thanks for watching.
Michael, I have a cape cod house with a double-ridge pole running the length of the house. I believe that there is not enough opening in the ridge to allow the air to escape. The standard maximum opening for a ridge vent is 3 1/4" and if you add 2 - 1 1/2" ridge poles, that only leaves 1/4" gap total (1/8" on each side of the roof). My roof pitch is 9:12. Is there an extra wide ridge vent made that would allow me to cut more of my roof out to have proper ventilation? Thanks
I am so sorry I don't have an answer. Are there any roofers watching that could help answer that? Have you contacted local roof/insulation supply store?
Michael, thank you for the videos. I watch and learn. For the “whisper” fan, you had it installed high in the attic and exhausted into the soffit? I have mold on the north facing side of my roof sheathing and have pulled my hair out to address the challenge (mid Atlantic area). Could this be my next attempt to fix my issue?
Great video. What did you use to connect your ducting to the soffit vent?
We used a standard 4-in aluminum flex duct. Thanks for watching.
Hi, Where the link to the Whisper Fan? I'm not seeing it
Hi, sorry - here it is: diy.crawlspaceninja.com/fans/
I put a common box fan ( mounted horizontally) .... right under the "peak" of my attic roof, using 2x4 supports, blowing "up" toward/out the ridge vent above. Note....I have eaves / soffits with open holes providing the incoming air, so I am not creating a preferred path sucking from the air-conditioned living space.
I bought a old house (renovated) that doesn’t have soffit vent on them but has sliding windows on the side where it used to be gabble vents before. I’m having problem with minor mold growing in the back of roof during winter. I installed a window fan for temporary fix to exhaust heat and bring fresh air to my attic. So the question is, should I install roof vents ventilation for the permanent solution?
Thanks for information, what if your attic has paneling already and you want the whisper pan
Hey! Feel free to fill out this form so we can discuss in greater detail - buymeacoffee.com/csninja/e/111638
excellent video I have question should be exhaust be installed under the radiant barrier or on top of the radiant barrier?
Thanks for watching! I think I understand what you're asking.. it shouldn't matter as long as the exhaust is going to the outside.
Wouldnt that create negative presssure and pull in humid air, possibly causing condensation on a/c ducts?
The air temperature outside is typically lower than air temperature in the attic. Condensation can form whether your attic is ventilated or not if dew point is at a level to cause ducts to condensate. In most cases, bringing in cooler outside air will help keep attic cool. Making sure your ducts are well insulated and not leaking air should decrease chance of condensation in a ventilated or non-ventilated attic. In some instances, regardless of ventilation, a dehumidifier is necessary as well to prevent condensation. Every attic, situation, and climate are different so it may be worth consulting a local professional to address concerns in your area. Thanks for the comment!
@@CrawlSpaceNinja who do I call to do this type of work? An HVAC company or a roofing company? Or ?
My attic has dozens of round soffit vents fitted with a screen mesh. IMO, the square mesh seems pretty wide. Today I had to seal off a small gap that some paper wasps found near some of the vents. I watched them get confused after the gap was sealed, and I've noticed that they don't go into the round vents right next to the gap even though it seems like they could easily pass through the mesh. I've been concerned that they might figure out they can sometime, and that I should probably get a second layer mesh to add behind the existing. It's just that these are very difficult to reach from inside and there are a lot of them. Is there a special reason they don't already enter this way? Maybe I don't need to do anything? I've lived here for years without issues, but I want to be safe.
Yikes. Let's dive into this together here is a link to where we can - crawlspaceninja.com/crawl-space-help-faq/
@@CrawlSpaceNinja turns out they figured out last week that they can get in this way. I ordered some soffit vent mesh screen covers. And I'll be removing whatever they are currently building in the attic now. No fun.
This advice (powered attic vent) seems to go against current building science practices from people like Allison Bailes, Matt Risinger, Joe Lstiburek, Martin Holladay, and Fine Home Building, among others. Is this advice for a particular situation or climate? I thought the main consideration of venting the attic was moisture control. What about air sealing and insulation considerations? Thanks. I enjoy your video’s but this one confused me.
Crickets
First step is to keep the heat out. If you can avoid the attic from heating, that is always the better move. But once the heat is in the house, and in the night it is cooler outdoors, nighttime ventilation is definitely a very good move to avoid overheating in the summer. But the control settings need to be tuned to only ventilate when there is cooling demand and when the outdoor temperature is low enough.
I have a ridge vent. Could I use a whisper fan to increase the air flow toward/out of the ridge vent?
That should be doable. We have done it in the past.
We have a ranch style house central NC with a metal roof with a conventional attic with full length soffit and a ridge vent. We also have gable vents at both ends and I have a thermostat controlled power vent in one of the gables blowing out. I have air sealed pretty well in the attic and we have R-49 batt insulation (R-30 one way and R-19 the other way) with the baffles to keep the soffits clear. I have read many differing opinions on what if anything I should do differently. I have seen keep it the way it is or to get rid of the power fan and block off the gable vents leaving only the soffit and ridge vents. Any advice?
Hi Sean, as we talk about in the video, we recommend ventilating the attic. It sounds like you're doing everything right. Are you finding that the rooms below your attic are still uncomfortably hot or cold depending on the season?
A side note from Michael, you should only have 1 type of ventilation, ridge or gable. Not sure which journal, maybe JLC, there was a test if you had both, you will lose the benefit of both. They kind of cancel themselves out. Heat rises so the best one for removing heat is the ridge vent, assuming its of adequate size.
@@CrawlSpaceNinja We don't notice much difference in temperature. The concern was whether the gable vents were reducing the effectiveness of the ridge and soffit system. The other concern was whether the power fan electricity use was more than the energy savings of a cooler attic.
@@SJ-gd6bo That is what I was wondering about having both approaches to ventilation/cooling. It seems like the "belt and suspenders" approach the builder took for attic ventilation might not be better than ridge and soffit alone.
That's true! Over venting can be an issue just like over sealing. Thank you for bringing that up. It's all about balance.
Attic should be vented year round. In the winter if there is no ventilation warm humid air from the living space(shower, cooking, the people inside just breathing) will migrate into the attic and condense on a cold surface…. The roof deck. Also Ice damming can occur in a vented attic assembly if the attic is not as close to
the ambient outside temp as possible. In my opinion in a vented assembly: make sure air sealing between living space and attic is done, make sure adequate insulation is present, make sure all appliances are vented outside not dumped in the attic, and make sure your attic is properly ventilated. Several roof vent calculators online. I see this mistake all the time when people put trash bags on their whirley birds. It says on the box Do not cover lol.
Have you ever dry laid concrete to get rid of moisture on a dirt floor crawl? Or is it a bad idea?
Does it make sense to have an attic fan and a whole house fan?
You should feel a difference in interior temperature if the outside is cooler than the inside. Attic fans actively move air out of the attic, which makes them a better choice for ventilating the attic. The whole house fan only transfers air from the house to the attic.
@@CrawlSpaceNinja yes the whole house fans do transfer air from house to the attic. but let's not forget early in the summer morning and late in the evening cooler air from outside with doors and windows cracked open transfer that cooler air into the house keeping the inside of the house cooler and less utilization of the Air Conditioning. which is less cost on one's energy bill
Where can I buy whisper fans ?
You can find all of our fans here: diy.crawlspaceninja.com/fans/
Hi Michael, great video. I installed a gable fan in my attic the thermostat stopped working, so I turn it on and off at the switch. I live in the San Fernando Valley in So. Cal. I'm thinking of installing a small Evaporative Cooler on the opposite gable. Any advice? Thanks in advance. { :-€) GBY
One of the issues I've heard of is fire in the attic. Besides having sensor and automatic shutoffs, is the ventilation design going to impact safety?
Rather than venting to the sofit, can you just vent it out one of the ridge vents?
Need to research a little more. Understand that soffett vents are at the eves of the roof or bottom of the roof/ attic. Ridge is at the crest of roof.. air goes from bottom to top. Blowing air out of the ridge vent without a soffett venting system will be like having somebody blow at you from across a hot room with no air movement.. you might feel the blow but wouldnt effect anything.. had a buddy install a big ass fan on an attic window he had with only having soffett vents and no gable or ridge venting. When he turned the fan on the first time it blew every bit of blown in fiberglass insulation through that fan into his yard almost where it was sucking the air through the only place it could through what few soffett venting he had.. but is what you should expect putting a 5 foot round industrial turbine fan on an attic window.. he could fumigate the whole house and suck out all of it in a half a minute with that thing.. said if he left the attic hatch open itd close every door it could in the house...
Hi! So I rent the attic space in my house now and it’s been getting in the 80’s outside..I have a thermometer in my room and even at 10-11pm it reads it’s 85 degrees. It’s clearly not insulated because it gets super hot in the summer and freezing in the winter. It may be ok if it was just me, but I have a dog that is sitting in the heat. I tried using AC window units but they seem to overwork and it is too hot for them to work. I don’t know what else I can do to try and keep it cooler.
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And thank you for watching!
Get a window fan. What is the difference in outside temp and inside your attic space?
I am getting ready to build a new house and have been looking at using a roof decking with a foil backing as my radiant barrier. You stated in your video that there needs to be an air gap between the barrier and the roof. Do you feel this foil backed decking is an adequate way to use a radiant barrier or am I wasting my money?
I'm not familiar with that product, so not too sure. I'd recommend reading the install instructions/claims of that product. The radiant barrier we featured must be installed the way we discussed but there are even radiant barrier paints. Unfortunately I am not as familiar with those products either.
I have a double envelope house with a passive solar heating system. It was built in 1980. One feature of this house is that it has two closets on the highest level of the house (on each side) - both containing a couple vents. I believe these are there to allow warm air to leave the house as it rises during the summer. The problem with these vents is that they allow too much cold air in during the winter. When I bought the house, the closets had foam insulation that could be stuffed in the doorway of these closets to help keep the cold air out. But this does not do a good enough job. I'd like to also put some tight-fitting insulation in the vents themselves for extra insulation (I would then remove the insulation in the spring/summer). I'm wondering, can I treat these vents like crawl space vents to insulate or is there a better way? Should I cut a piece of foam insulation to stuff in there? Or fiber insulation? Or both? I feel that my house could be much more energy efficient if I found an effective way to insulate these closet vents. Anyways, being that I am a new homeowner I have enjoyed your videos and have subscribed to your channel!
Hey Stephen Delwiche,
Installing temporary insulation in these vents during the winter months would be best practice. Foam insulation would likely be the best solution here.
Thanks for watching and have a blessed day
Hi quick question my garage has no ceiling, I'm planning to insulate and put ceiling on. Its a 300sqft. Can I just put window vent on the attic? I live in California
Hi, I'm sorry. I would check with your local codes department or a local contractor for that question.
Hi. Is there any reason to put in 4 new passive flush vents on my new roof? I have 3 gable vents, one has a new attic fan and tons of soffit vents. I will be eliminating 3 old half dome style vents when my old roof comes off. Thanks!
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What attic temp is too hot? I’m seeing a max of 120f on the hottest Summer days.
There are many theories and opinions of what attic temp is too hot. What I am seeing from most roofers and inspectors is try to keep attic temp within 20 degrees of outside temp. So if it is 90 degrees outside, 110 degrees in attic is great. Keep in mind these are guidelines and in some cases may be impossible to reach without major corrections like radiant barriers, air sealing, etc.
I installed a gable end attic fan this morning. Btw there is currently 1 inch of old cellulose insulation in most of the attic.
Yesterday it was 105 outside and 74 inside at 70% humidity outside and 53% inside.
Today is the same outside, and 67 inside at 49% humidity.
We have no soffit or ridge vents. The gable end vents are 2ft by 3ft each.
Wow, thanks for sharing and watching.
My house doesn't have gables and I'm reluctant to install a roof mounted attic fan for fear it will cause leaks. All the eaves around the house are vented. Are there other options you can recommend to increase air flow through the attic?
You may be able to duct a Whisper Fan to the soffit vents.
Look into the ridge vent option. Air will enter though the eaves vents and exit out of the ridge vent at the top.
Is it best to leave attic stairs open in the summer? I have an attic fan, a ridged vent and the stairs are in the garage not the house.
Yes! I pull the stairs open and leave a 3-4in opening on the bottom of the garage door on a 100 degree day. You will notice the ac being more effective at keeping home at the set temp especially if you have a split hvac system where the other half is in the attic.
Keep your attic door closed unless your home is naturally ventilated and not air-conditioned. If you're in that situation, it may be better to just open the windows on either side of the attic and close the door.
@@CrawlSpaceNinja thanks
@@anbuknight thanks
I love all your videos! I wish you were in Texas! We have a second floor attic area above a bedroom that keeps that bedroom extremely hot. We are trying to find a solution. We just had a brand new roof put on. We didn't notice the extreme heat until this Spring. We cut a small area out of the ceiling so we could see what was going on up there. The space is a little insulated, but obviously not enough. I don't think I or my husband could fit up there to take care of the problem. Any suggestions?
Thank you for your support. Since no one can fit in there, the best recommendation we can give, is to YES hire someone.
I'm not seeing a link to the whisper quiet fans.
diy.crawlspaceninja.com/panasonic-whisperline-in-line-fan-model-fv-10nlf1e/
You mentionned a link to the whisper fan (4:15) and I don't see it.
Here is a link to all our fans! - diy.crawlspaceninja.com/fans/
Never thought to install a whisper fan in attic .. I’m guessing it’s like an exhaust fan with 4” duct ports on each side..a in and an out..
Yes, the WhisperFan works great for ventilating attics!
@@CrawlSpaceNinja could I run the soft duct from the whisper fan and strap it next to the ridge vent and it perform properly
How about leaving attic door in garage open in summer?
We wouldn't recommend that... at least our garage is really hot
Attic ventilation is just as important in cold weather as in hot, if not ventilated correctly for cold weather you will have condensation problem, freezing and thawing causing a problem.
Great point. Thanks for watching!
You r very informative thank you 👍
Interesting video. We have soffits in our home and had a ridge vent installed when we built. We haven’t finished our attic space yet (home was built as a cape) so I haven’t had to deal with venting what will be the true attic yet. Good suggestion with the whisper fan.
Thanks for watching! Let us know how it goes.
Forget the home i live in the attic im dying bro
That doesnt sounds fun!
Never blow a attic fan into the attic, summer rain and you’re blowing water all inside the attic.
Great advice, thank you
hmm... whisper fan... I don't know man. whispers are usually associated with dirty little secrets.
😂 Luckily it's no secret that the Whisper Fan does a great job.
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