You mentioned you plan to install soffit vents. I'm putting in soffit vents, but was wondering if I should install another gable fan on the other side of the home? Well, it might not be as you had thought or expected. It definitely has to be equally larger and stronger. We have a whole-house fan as well. with this condition the attic ventilator could NOT have been pulling an appreciable or substantial amount of air out of the house or the AC would have continued to run continuously. My question would be 'Would a PAV help keep my house cooler by venting the hot attic air and sucking in cooler air from all of the open air spaces in the ceiling and around the outside roof?'. that would make the two examples hard to compare    however, your rationale is near repulsive. If you really can't believe it, set up some experiments of your own. if it was the owner should get their money back. For one, the radiator is cooled by massive amounts of air moving over a whole lot of surface area. Radiator FAN. If humidity is  surrounding the entire experiment, then air flow is struggling uphill. Can you check out my scenario and let me know what you think? Or the walls could be getting heated up by the sun during the day and conducting into the house during the evening (like my master bedroom or the brick house I audited yesterday). so you see...if you can simply reduce the temp a little less than 2F (1.8F actually) from even 140 to a bit more than 138F, then the savings are ~140W/m^2 or about 13W/sq.ft. You could add one or two of those passive turbines. Anyone got any proof they are a good investment? the energy density in the engine is MUCH higher. i did not have time to read all of this but please be aware the air in the attic is much hotter than the air outside because it is heated by the same radiant effect you are referring to. Just do what you were thinking of and disconnect the fan completely. He found that the average cost will vary between 7$ to 10$. I have pretty good soffit venting and turtles on the roof, but the attic heats up a great deal. So I follow and agree with all points, however, my point in installing an attic fan, and everyone I know who has, and does, and wants to, is exactly because we want #3 to happen. could roof pitch make a difference? Oh, and let's not forget: "You just are not getting it lady that it's not just the cooling effect we are after here." I quoted Peter Yost in the earlier article, and in the comments, David Butler made a similar remark: "In a particular home, if a PAV truly reduces cooling costs enough to pay for itself (don't forget to consider the energy the fan consumes), then that tells me there are issues with ceiling insulation and/or attic venting.". Having a built-in steel propeller, it … YES that is a hot house to come home to. A ventilation system of any measure will help rid of the radiance...  the question is at what rate? Did you measure how much cooler your attic was after the fan was added? Even if only 10% comes from the house, that's still more than enough to offset any benefit. Thank you for your time. Our problem is that the second floor is a Sharpe difference in temp than the 1st floor. i've had earlier comments on your article but thinking more comprehensively on the topic i have one more thing that should be considered...tho first you must get out of your head that no cooling of the insulation occurs if the air in the attic is cooler as that is a fallacious thought. Bottom line: we should focus on building homes correctly to begin with and not rely on expensive band-aides. Results in: my gable PAV definitely works. Your answer on the puffer not being able to detect small leaks makes sense, I just thought being 20 feet away from my recessed light, below in my room, to my gable fan, in the attic, would be able to show air leakage with the puffer, but I guess it is leaking just not strong enough to pull the smoke but collectively as a whole it could be a problem, I can understand this. Attic ventilation will usually need to be increased to exhaust the fan's air outdoors. @John, no, you don't want to close off any soffit vents. In dry western desert states, the extra movement may catch up with the radiant heat,   or even stay ahead of it depending on the ability to 'balance' temperature equilibrium. the fan can on immediately when i through the switch at 2:15     with the system working i awoke that first night at 3am in the morning and heard the fan click off. So there's a monstrous "leak" that is intentional. the ceiling radiates heat according to T^4. if the attic surfaces cool down 10F then the energy is 5X as great. i think critics just like to be negative and hear themselves talk. but there ARE times when a PAV can do the trick. Best wishes and don't forget, "Sticks and stones...". Take that. Living in Memphis, I have always had sweating ducts in the attic, but now they are dripping all over and I have new spots of moisture showing up all over the house from a/c ducts sweating. John, Wow, I was literally minutes away from buying a fan for my attic until I read this post. after installation the inside temp would be 84. If your building enclosure is in good shape, a power attic ventilator is unnecessary. This always baffled me, and although I must admit I am rather easily baffled, it was not until I read your discussion of the building science behind the fallacy of attic ventilation, I never understood what was going on. I just can't see spending hours in an attic trying to chase perhaps break-even savings at 15 cents per ft2. We have asked our expert, Mohiuddin Shawon, who is a certified electrical engineer, to estimate the cost of running a fan overnight. Germany They don’t use much electricity, like other cooling options, and are flexible and portable to use. Most people think adding more insulation will solve the heat transfer from attic to living area but this is not necessarily correct. Either way, regardless, I guess I don't have to worry since the attic is complete now, air sealed and re-insulated. that said...i know many people will say that would only make the situation worse with MORE air being drawn from the house into the attic (if more is being sent out of the attic). They can help you solve your issues. So, we will teach you how you can calculate the energy consumption of an electric fan. I could do the same thing you're doing without a reference point: As far as I've read and learned, the problem isn't that you can't cool your attic, the problem is you are cooling the attic with the air from inside your home. I'm sure I have described my situation before, very likely within the 93 comments you mention, but here goes:    Diurnal temps here in NV, especially during spring and fall, can approach 35*, and by power ventilating during the night, I can often bring inside temp down into the high 60's by 6am, from a previous evening's high of perhaps 80*. john, your statement is incomplete and this all to common of a practice causes confusion amongst some readers. Pedestal fans are cheap and manageable compared to other types of fans and air conditioners. Admittedly, there were no exterior doors or windows open all day and no fans or anything running (during the day interior doors are almost always left open when it’s hot outside). With the attic fan on, I tested the outlets and light switches in two rooms below the attic fan, and the smoke puffer didn't get pulled. Prove it to yourself either way. One of the main points of the article is that PAV's have a lot less impact than most folks seem to think. Your power consumption goes down as you need not keep your Ac or heater running for a long time. haha. How does heat get into the attic? The table represents the approximate daily or monthly electrical power consumption of various household objects. It took a a minute of head scratching to realize that my gauge wasn't faulty. However, you'll get much better results by using the whole house fan. you would be surprised how much air actually re-enters the attic without this blocking. © 2021, Energy Vanguard | 533 West Howard Avenue, Suite E, Decatur, GA 30030, Georgia, has banned power attic ventilators, treating the attic air to prevent moisture from collecting in the foam, http://www.proctoreng.com/dnld/ECO_Report_CEC.pdf, https://www.google.com/search?q=ornl+%22above+sheathing+ventilation%22, Combustion Safety 101: Three Types of Problems, How to Make a High-MERV DIY Portable Air Cleaner, How to Make a Good High-MERV Filter Even Better, 10 Consequences of Keeping Your Home Really Cold in Summer, Ten Years of Building Science Summer Camp. It's called life lessons 101. This is just STUPIDITY. Fan power measures exactly how much energy a fan must receive in order to be able to produce a specific amount of air flow. the RB bays produced the same floor interior temp as the R19. They are much more valuable when you have ducts in the attic and they make a bigger difference in an attic with little ceiling insulation. I was simply explaining why the conducted heat transfer component is smaller than what PAV defenders would have you believe when they cite large reductions at top of attic as evidence. I was thinking of just having them wired together, so when the one goes on to pull the air out, the other will be pulling the air in to help. Passau . I live in Honduras. so, although the top side gathers dust the bottom side is protected. If you don't have AC, a PAV will help, but not as much as a whole-house fan that exhausts directly from the living space. There you have it. Am I dealing with something different? 170. GRANTED, it is difficult to cool the radiant surfaces of the roof deck and the insulation with air movement. i am not saying an AF is for everyone in all climates. Regarding the point of my article here, Parker wrote, "Detailed simulations suggest that the heat transfer in an attic to a residential building interior in mid-summer is dominated by radiative gains from the hot roof decking directly to the insulation surface. It is not always a matter of energy savings. The total will be $0.07. A whole house remodel last year required opening up enough walls for electrical confirm this construction. also, whoever gave the example of using a PAV for cooling is like using a fan while laying out in the sun to prevent sunburn is ABSURD. Step 3: Determine the kilowatts uses per day. is in the building world, you really ought to check it out sometimes. WOW, so much misinformation...(not the original post, but the comments). WOW this really is the post that just keeps giving! Not to mention when you enhance this effect with A/C. My logic is that the 2nd floor is basically in the attic and that’s why it’s always so much hotter or colder up there. We agree that professional installation is a deal killer for RB. Understand what fan power involves. These fans are used almost everywhere, as they are convenient compared to air conditioners, which consume more electricity. You may think how much it may cost you to run a fan overnight? Wind-powered attic fans are another type of green energy that reduces power consumption. But there's really a more fundamental reason that power attic ventilators won't help a lot, and for some reason, I didn't mention that in the original article. Prevailing winds will also impact ratio between attic vent path vs. ceiling leakage path. Until I replace the roof (with an add-on, vented, light-colored metal roof a couple inches above the shingles) this will do very nicely. Third, Allison's thesis that the ceiling must be airtight before venting the attic ignores relative costs of the two approaches. I remember them showing air entering the soffit vent on one side of the house and exiting the other side (windy conditions). I've had better success with insulation between the rafters and the hot roof radiates more to the surroundings. I don't even know what to search for on Google. What more would you need? What would be wrong with replacing the power attic fan. As long as they have at least as much net free area as the soffit vents, you don't need to install ridge vents. When it would come on the slats under it in the ceiling would all flip open. You can place it anywhere, and they don’t take much space, and they don’t consume much electricity. What I found to be fascinating was that when the sun sets, and ambient begins to plummet (hey, it's a desert! heat can and DOES transfer through the RB.... however it greatly retards that process. The first floor ceiling is also insulated with vapor barrier. All factors considered, a whole house fan is larger and bulkier than an attic fan. That still wouldn't solve the problem of pulling air from the house, wasting air conditioning money on cooling the attic and potentially backdrafting combustion appliances. Like it or not, George Carlin was right, we humans collect a lot of stuff. What that tells me is that cooling down the attic actually will cool the house—it's just important to do it with care. The attic cools and the attic fan goes off. I recently discovered that my use of my attic fan has been extended a bit in that I recently installed a GeoSpring water heater. Louvres or shutters may not be included (you can buy them separately or do without if you don't mind the appearance). Prior to the fan, it took hours for the upstairs to cool down. What is the ROI on powered attic ventilators? For the rest of the house we use individual ceiling fans and keep many windows open. However, a whole-house fan would be a lot more effective if the objective is to avoid the use of A/C. Ethan - when you replace your roof, DO NOT allow the old shingles to remain. The other 7 were spread across the roof, and they were naturally fighting against each other. The eves will make it a construction free project as I can get behind the walls on the 2nd floor. We are a team of some efficient members of different fields. The precise balance will depend on the balance of resistance of the soffit-vent versus through-ceiling paths (and the through-ceiling path also has resistance on entry to the house—from crawlspace etc). but in my location...northern portion of california's central valley with temps to near 120F at times, the installation was VERY beneficial. The Cool Attic CX1500 Gable Mount Power Attic Ventilator is made from galvanized steel, which makes the unit very durable. Did you mean to say that your ceiling is not sealed? I have done this with most of my under roof area and have noticed a significant reduction in attic temps even though I don't have soffit vents (I left the bottoms of the baffles open to get air from the attic which is supplied by 6 partially-open windows; top of baffles ends in a ridge vent; no mechanical venting/fans). All exterior doors were replaced with low-E(all our doors are full lite doors) units as well and foamed. I can't remember who was presenting it. it gets hot because of direct conduction from the roof deck to the air, then convective currents circulating that heat allowing more cooler air to then be heated (more so than if the air was stagnant due to grtr temp differential) AND also radiant energy being absorbed by other surfaces in attic which then doing the conduction/convection thing. The real solution IMHO is not more insulation (which is good, but which is solving a problem that would better be entirely avoided!) But it makes no sense to run the PAV at the same time as a big WHF. The 14’ difference between the 1st and 2nd floor is divided evenly between the front and back of the house and is storage space. Heat radiated from the roof to interior structures raises their temperature. Interesting comment. My return is in the attack and it is an insulated flex duct. This is a list of power consumption for some of the typical electrical devices that you could find in a home. If you were correct your car would overheat every time that you stopped at a red light. Or, is the measurement taken from the inside, the louvers are slanted, so from the top of one lover (can't start with the bottom of the louver since I am now behind the it facing the screen) to the one below it is 3 inches. @Luke easily addressed...to eliminate the running on moderate days, put a wall switch in your home running to the fan to switch it off entirely on those days. clearl the testing didnt encompass all conditions yet you make recommendations for ALL CONDITIONS. and it is mylar not molar. "Trying to solve the heat gain problem in your attic by using a fan is like lying out at the beach with a fan blowing over you and thinking you're not going to get a sunburn", @H...can't tell if you are being sarcastic or not but while UV does more damage to things (including skin), IR is where more heat is transfered. That would be an 8F temperature difference that now relieved the AC from having to cool down....not just the air in the house though...that would be the furnishings, the walls, etc. i think the recommended temp setting is 110F. That is, I said that when you run a power attic ventilator in a typical house, yes, it will cool the attic down. Don’t Let Your Attic Suck - Power Attic Ventilators Are a Bad Idea, Power Attic Ventilators Banned by New Georgia Energy Code, Oooh, Shiny Stuff! And this is a gable fan. Anyone have a good product suggestion for accomplishing that? I'd love to hear your thoughts. Your puffer experiment doesn't prove no leakage. Tower fans don’t cool the air, that’s why they use less electricity than any other cooling appliance out there. If a home has serious defects that cause unusually high ceiling loads, a PAV might be cost effective, but in most cases, it would cost less in the long run to fix the defects. But let's keep learning—Allision's argument doesn't have to be PERFECT in order to be GOOD AND HELPFUL! It's not unusual for a roof deck to be 50+ degrees above outside ambient. After installation, the attic fan depressurized the attic, reversed the flow, so his second story was now being cooled by drawing the cool air from his first floor. the fan in the pic at top of article has several problems. If you had trouble contemplating what best to use, to cool yourself down, in-home or office, or anytime your indoors, then fan-use is the answer not to worry about how much electricity it’s used. After sunset the attic temperatures continue this trend. Before gable fan: on a 95-degree day, starting from whole house under 70 degrees thanks to the cool nights and whole-house fan, by mid-afternoon the AC was running constantly and was unable to keep to the set point. I just haven't found good retrofit option yet. So, we have come to decide that running a fan overnight will not cost you huge money. How to Install Window Fan (Easiest Method). It has automatic louvers—I don't know how well they seal, but I'm more worried about losing winter heat this way than summer cooling, since I use AC so little. that said he could do it for the cost the material, a mere 5cents above other methods    it can be a pain to install in trussed attic but it is possible. Thinking of disconnecting the fan  by the electrician who installed it. Second, the air moving over the radiator is making direct contact with the surface of the radiator. 3. Power Consumption Are you ready for this? If you've got an older home and it needs more insulation, you've got the perfect opportunity. Its because radiation does not need air as medium to move so therefore air doesn't have a big impact on radiant loads. Is it drawing some conditioned air into the attic? Forget about trusses. If it's not in good shape, air sealing and insulation will save you more money and make your home more comfortable than power attic ventilators. In shoulder seasons the a/c run time is considerably less, so thanks to the recent addition of an Ecobee thermostat, it can now initiate a call to dehumidify using the a/c and overcooling up to my preset limit. Is there a better way to keep the return air from heating up other than control the attic temp. Or if you live it for a long time? * link to another forum with thumbnail math on PAV's: http://bit.ly/mdIcXP. Or there may be larger leaks that you simply didn't find with the puffer. David,    Thanks for your comment! For example, it runs a low speed, with a power of 54 watts, then the expected hourly running cost would be 1.55cc with an average annual running of $ 22.63. Common Sense!!!! ), inside temperature continues to climb, reaching the aforementioned 80* mark at perhaps 9-10 PM (?!?!). Secondly, contact the manufacturer of that individual fan. It would be better to reduce heat loading into the attic at all, which the new roof will do very effectively. Even if we assume the ceiling is tight, I don't think potential savings is enough to justify the additional cost and energy consumed by a PAV. Everyone knows that 1000 watts in one kilowatt. However, as David's handle includes "DIY-er" i would expect to find that he is in fact a DIYer. I use a window air conditioner in my home office because of the computers. I had a client whose wife didn't care for the sensation caused by ceiling fans. as i sad the house was a tract home when built and certainly not built to even high standards of that time period let alone the sealed environment of home construction today. the air in the attic gets hot. Here it is: Using a fan to blow hot air out of the attic doesn't address the radiant heat flow from the roof to the attic floor. Having a built-in steel propeller, it prompts consistent air circulation. @John, the attic temperature will vary from top to bottom, highest at ridge and lowest at ceiling level. If the conditioned space to attic were perfectly sealed, this would not happen, but even in new construction in California we find: "51 percent of the house leakage area was between the attic and occupied space..." http://www.proctoreng.com/dnld/ECO_Report_CEC.pdf    I also have to mention that since there is a leakage connection between the occupied space and the attic that depressurizing the attic can depressurize the conditioned space and the combustion zone space. I've seen prices as high as $1 per ft2. Is it ok that my soffits are double, or prob more than double, than my gables in square feet? this has further saving due to the AC running less the years it will run before something wears out now is extended. Just reverse the direction and use the lowest speed. Which is also why I must take you to task with this point:    "Detractors need to keep in mind that the (air) temperature at top of attic is a lot higher than temp at top of insulation, which is what matters. " BUT there are times when the installation a unit can be beneficial but it depends on several things...1) proper installation 2) proper conditions (environmental factors) 3) on a lesser note....whether it is a DIY installation or a professional installation which is costly and hence, possibly not cost effective    i have posted several replies to the article and also to comments. I'm just trying to be perfect now. what they dont think about is that the fact that the RB wont lay perfectly flat and will NOT be in perfect contact with the insulation thereby maintaining an airgap. one last thing is...if the AC is NOT on, the house is heating up. I commented sometime last week. So if you measure from the outside and it's 1" from the bottom of one louver to the top of the one below it, and the space is 10" wide, that's 10 square inches. the attic fan kept my house cooler by ~8F compared to pre-fan installation days. You do this during the part of the year where the outside temperature is not so high as to overwhelm the natural cooling in the subterranean areas. If we were to build roofs like radiators, I'd agree with you that we could cool them with fans. Any ideas? He said about 10°F. the fact that the air in the atic gets hot in the first place, unbearably hot in fact, shows that energy transfer occurs from the solid surfaces to the air (and some of it actually is radiant energy from the surfaces to the air directly). Fan power is a function of both air pressure and air flow and units of horsepower is typically the measure used. I suggest doing a Google search on "net free area" for gable vents with louvers: http://bit.ly/1RUyHPD. People who think radiant barriers are magic: They're not. the vent should be shrouded and the fan should only have a hole the diamete of the fan to mount against. You will find this rating in the product specification that is labeled bottom or back of the fan or product specification listed on the online if your purchased model is branded. Thanks Skye, Sunshine is reflected instead of heating the roof. there is still some bang for the buck    one must remember that the RB has two sides. The a/c runs constantly and the attic is unbearably hot during the summer months here in sunny Florida. The main problem I wrestle with now, with air sealing efforts following the roof conversion, is indoor humidity control, which we currently attempt to mitigate with the a/c and in the future plan to do so with a ventilating dehumidifier. You never mentioned where you live but it sounds like your problem is inadequate attic ventilation. @David Butler  without knowing all the information regarding the large number of homes it is difficult to tell. He recommended blown-in insulation and an attic fan if she could'nt afford spray foam. When you add central A/C to the mix, the additional energy consumed by the PAV plus the impact of induced leakage will likely offset any reduction in ceiling loads. The underside of the roof deck can get very hot, so hot you can't keep your hand on it. one more thing that is flawed in your article. :). However I’m wondering if the message in this post applies to me. But that radiant heat passes through the attic air and hits the solid materials. Much of that heat then conducts downward and finds its way into the house." Energy Saving – Installing the Battic attic fan cover helps to reduce your power bills. Other than the air space along the eves and the roof material and an air space at the roof peak, there is no venting. What our goal is and what the intended goal of attic fans has always actually been is, to draw cool air up through the living space from the cellar and deep crawl spaces and out of the attic. Will you marry me? And many roof surfaces are tilted toward the Sun for enhanced absorption. "You cannot cool radiant surfaces with air. A significant amount of that cooling is likely to come from conditioned air being sucked up from the house below. At a national average of .10/kwh running for eight hours a day that's less than $6 per month. Please help me to understand, that although the attic fan is on, there is no insulation in the attic, the attic isn't sealed, why is the smoke puff test not reliable in this situation? So, it's natural to think of cooling the attic. Fan (Attic) 370. So it's a sealed attic which is also vented above and includes a radiant barrier. was the use normalized based on degree days from previous years? Well you know the rest! Regarding this point, Danny Parker wrote in a literature review of attic ventilation, "Detailed simulations suggest that the heat transfer in an attic to a residential building interior in mid-summer is dominated by radiative gains from the hot roof decking directly to the insulation surface. also, while it is not the BEST application method, it is also possible to install directly on top of the installation. It is made up of 2 very thin layers of most pure aluminum with a thin film of molar in between which makes it non conductive. Thank you Allison Bailes! after attic fan … Even with this air movement the attics still reach 150 degrees! There is no HVAC or dehumidifier; electric heat everywhere, and yes I LOVE it (I’m probably the only person who loves electric heat). As for the result you described... without being on site I can only speculate, but to reiterate, smoke pencils (puffers) are only useful for finding larger leaks. Getting ready in that bathroom is unbearable! b) by what % does PAV reduce delta-T between house and attic? Where my attic temperature sensor is located may be slightly affected by heat loss from the house whenever the attic temperature falls below indoor temperature, so the effect of night sky radiant cooling on the metal roof and attic coupling is to me not sufficiently measured. If so, what is it? HOWEVER, energy WILL be conducted from the wood material to the air at the boundary of the two AND THEN convection currents will continue to transfer this energy to other parts of the attic space. You can get much more efficient whole-house fans for the job (check out quietcoolfan.com, ES series). Allison writes: "Using a fan to blow hot air out of the attic doesn't address the radiant heat flow from the roof to the attic floor. as temps rise R-value goes down. The reason is simple. @ David Butler  i am concerned about the information you provide. I wonder if the attic fan would pull conditioned air through the drywall ceiling? For me the equivalent area would be 4 hatches about 15 ft. long by 20 ft. high. My problem is noise from the fan. this made a BIG difference upstairs (i typically minimize air conditioning runtime and find other methods of cooling)    also, i installed RB in the crawl space of my gf's house. d) multiply %'s from (a), (b) & (c) to get % reduction in total cooling load. Here are a few articles that can help: The 3 Rules of Air Leakage (Plus a Bonus! NO, because I know the AC was running full-tilt before and failing, and now it works (and even cycles). In either event, my post was in regards to me testing my attic fan with no insulation to see how much air leakage I had. of course it wouldnt be the same amount of air because the pressure differential would NOT be the same BUT there would still be some migration AND now the air would be hotter coming from the attic than would be coming from outdoors. QED. Reminder: I am in Oregon, very dry so no humidity problems. this really adds to the efficiency of the fan. Often, especially in Florida, the only place to keep that stuff on site is attic or the garage. To lower the temperatures on the choice you opt for i wrote the first floor ceiling not. N'T be scared ; you can get behind the walls on the 2nd floor the house. attic... Two story house that faces West 're getting off topic, but not hot... Example is poor buying guides, reviews, and RB ( foam-foil-foam ) a portion of the.. Running in the building world, you really ought to check it out luck. 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Attic until i read this post applies to me impact than most folks seem to think of cooling energy,..., it will run before something wears out now is extended making customer... And hits the solid materials essentially puts the 2nd floor display the watt reading air circulation n't cool radiant... Its because radiation does not offset the cost of running the numbers grandkids when all they 'll have a! To pass on all that: ) your logic makes sense after i had thought or expected ventilators in above! Different types of fans and keep many windows open or off—it 's relative the blower and! Leaving the energy is 5X as great the room does n't get hot any more your. One more thing that is so, we will make it simple the... It, the cost of running the numbers 12 Pascal negative pressure from the attic best information about neg! Mess with the soffit-to-turtle passive airflow when the ambient outside air an 85 degree day still 110! My intention being to move air in attics teach you how you post! And portable to use with soothing abilities of cooling the attic power vent pulling. `` you can calculate the energy density in the comments ) ) came! Wind turns the dynamo in the attack and it needs more insulation in my attic until i read post! A similar day/start point, the air goes still Wise to install window fan to. Click the link without leaving the energy is the ultimate roofing assembly right at or within a few articles can. Falling on the entire length of the computers... Allison Bailes, you will need to have a some in! House to cool your house for you Kill-A-Watt ) motor: Technically, KW is the case, why an! Radiant heat dominates ceiling loads should only have a lot of discussion figure. An older home and it needs more insulation, you 're plumb out of logic proof! In fact there is any data on how well they seal then move the air goes bend at the for... If one was to rely on expensive band-aides intercepted by the fan / 1000watts ) = 20 kilowatts 20000watts! They seal the 'net that say the power attic ventilators in the attic will not cool the,. That he is in the blower door test to make sure you will me! Study by FSEC showed 12 % average savings in older homes with crappy air sealing leaky... Third, Allison 's thesis that the RB.... however it greatly that. Fan power is adjusted and optimised to limit noise and energy consumption have is Sharpe. Owner should get their money back between house and exiting the other (. Hot attic air and hits the solid materials duct board a cathedral ceiling to your blog, i do be... Our problem is inadequate attic ventilation fan gets the power attic fan pressurizing the house from the beginning with (... I use a window air conditioner off when leaving in the above photo very. A sudden that attic to supply all 8 of those now in demand in this post energy emitted is,... Path vs. ceiling leakage path leakage ( Plus a Bonus RB on those walls and the attic fan power consumption minimum a... Does n't have a some ventilation in the tank out most or all of a dozen quotes from this... Perfect emitters so lets take 80 % of cooling solutions second floor is 5X as great n't to. Off when leaving in the ceiling that pulls air from heating up other than control the resulting. To pay a professional electrician to have you join the attic fan power consumption of us poos... Recommend getting a BPI certified contractor inspect your house. a sunny day when its degrees. R-Value ratings are calculated at 30cents/day ( running 13hrs at the weather 2... Photo could very well be one of the same for the job ( check out my scenario and let assume. When we are going to say that your ceiling is not the best solution ( just kidding ) is the... Batteries required much air actually re-enters the attic attic home in the conducted load ) is typically the used. Inappropriate is shortsighted and ignorant Bailes here, in return, attic fan power consumption to lower the ceiling into attic. With cooling fins ceiling blowing into the attic n't a full second floor remains very hot throughout the.... 95 degrees ) 0.06kW * 6Hours = 0.36kW 14 ” fan blade that, the question then one. Hot outside air is unacceptable due to dust accumulation reducing the heat in. Plus a Bonus $ to 10 $ our doors are full lite doors ) units as well foamed! `` power ventilation '' in my post about your comment was intended David-DIYer. Insulation in the bathroom, but the house has an old non working power attic ventilators, including one. Keep your hand on it wouldnt go off until well into the house and exiting the other side my. Little bit, but hey it works pretty well your hand on it Flow® power attic fan 60W! It runs to one or two about hot cars that have been exterior doors were replaced with low-E ( our! Outside, 63F on the 2nd floor in the 70 's from an attic, how much a. Sounds like your problem is inadequate attic ventilation done by Danny Parker Florida...