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Posted: 5/4/2021 2:09:20 PM EDT
[#1]
Attic fan.
But not like this:  (Install a thermostatically controlled fan.) |
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Posted: 5/4/2021 2:19:56 PM EDT
[#2]
Is your overhang area and your roof ridge vented? Vents on each end of the roof? That's about all you can do unless you are a powered fan.
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Posted: 5/4/2021 2:21:27 PM EDT
[#3]
A pick axe a couple times though the roof should do it
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Posted: 5/4/2021 2:38:39 PM EDT
[#4]
Quoted: My home has a heat problem and it in part has to do with the attics inability to vert off heat. What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. |
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Posted: 5/4/2021 2:59:12 PM EDT
[#5]
Quote HistoryQuoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. Quote HistoryQuoted: Quoted: My home has a heat problem and it in part has to do with the attics inability to vert off heat. What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. Insulation in my attic is virtually nonexistent. Should have looked in to this before now but here I am. That is currently being addressed, likely with spray foam insulation. The exhaust fan seemed like a good idea until I read your post. Help me understand your reasoning. If the attic (hypothetically) is at 125 degrees in hot weather, and an exhaust fan is installed with a thermostat to vent hot air out, and the attic space drops in temperature, that will not affect overall house temperature?  |
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Posted: 5/4/2021 3:06:17 PM EDT
[#6]
Quote HistoryQuoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. I completely disagree with your assessment. The installation of a thermostatically controlled ventilation fan five years ago, which comes on when the attic reaches 95-100 degrees, has driven down my cooling bill by AT LEAST 30%. |
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Posted: 5/4/2021 3:22:14 PM EDT
[#7]
The problem is most likely that the AC is run through the vented attic, where the R8 insulation on the ducts isn't enough to keep the air from warming up.
The correct answer is to create a conditioned attic. Doing that is... really fucking hard. Because you basically have to roof the house again to do it right. |
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Posted: 5/4/2021 3:25:09 PM EDT
[#8]
Quote HistoryQuoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas.  if you’re drawing air through the house with an attic fan I can agree with you. If you’re cycling air through the attic space to effectively cool it down it has to have a positive effect on the home’s living quarter temperatures.Insulation on the attic flooring will make a big difference in your AC’s ability to keep up. |
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Posted: 5/4/2021 6:53:15 PM EDT
[#9]
I ran an attic fan for decades along with radiant barrier insulation on the underside of the rafters and it beats no fan at all. However a fan pales in comparison to a full ridge vent, which was installed with a new roof, the difference is night & day.
For the ridge vent to work properly you must have soffit ventilation, in my case I installed Hardi ventilated soffit panels years ago so no issues there. |
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Posted: 5/4/2021 6:59:28 PM EDT
[#10]
My house has pretty airy soffits, gable vents, and lots of turtle vents. It does not get very hot. I honestly think gable vents do more work than people realize.
We plan to go with steel roof with insulation under eventually, and ridge vents eventually, which will be even better. |
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Posted: 5/4/2021 7:14:35 PM EDT
[#11]
ridge venting on my house really does well.
The whole point of my roof is a vent. |
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Posted: 5/4/2021 7:50:43 PM EDT
[#12]
I put a white metal roof on mine. Dropped it an unbelievable amount. In winter, who gives a shit, it's already covered in white.
I have A ridge vent but I also took out two windows and put in large screened soffit vents. |
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Posted: 5/4/2021 8:08:27 PM EDT
[#13]
Quote HistoryQuoted: Attic fan. But not like this:https://www.ar15.com/media/mediaFiles/153820/Screenshot_20210504-140748_DuckDuckGo-1929351.jpg (Install a thermostatically controlled fan.) Yep cut a hole for an electronic fan. Last go around I got a solar powered on it wasn't cheap, but lower electric bill. |
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Posted: 5/4/2021 11:28:13 PM EDT
[#14]
Quote HistoryQuoted: Insulation in my attic is virtually nonexistent. Should have looked in to this before now but here I am. That is currently being addressed, likely with spray foam insulation. The exhaust fan seemed like a good idea until I read your post. Help me understand your reasoning. If the attic (hypothetically) is at 125 degrees in hot weather, and an exhaust fan is installed with a thermostat to vent hot air out, and the attic space drops in temperature, that will not affect overall house temperature? https://storage.googleapis.com/idx-acnt-gs.ihouseprd.com/AR753508/file_manager/Blog%20posts/atticventilation-1.jpg Quote HistoryQuoted: Quoted: Quoted: My home has a heat problem and it in part has to do with the attics inability to vert off heat. What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. Insulation in my attic is virtually nonexistent. Should have looked in to this before now but here I am. That is currently being addressed, likely with spray foam insulation. The exhaust fan seemed like a good idea until I read your post. Help me understand your reasoning. If the attic (hypothetically) is at 125 degrees in hot weather, and an exhaust fan is installed with a thermostat to vent hot air out, and the attic space drops in temperature, that will not affect overall house temperature? https://storage.googleapis.com/idx-acnt-gs.ihouseprd.com/AR753508/file_manager/Blog%20posts/atticventilation-1.jpg The picture you posted is rather silly in assuming a change in 40 degrees. All an attic fan will attempt to do is replace air inside the attic with air from somewhere else. If its outside air it will only exchange it with a slightly lower temp air from the outside but it will never bring it to the exact temperature as the outside air due to radiation. The reason your attic is hot is because of the roof acting as a radiant barrier. Science, real science, tells us you cant cool a radiant barrier with air. Its just not possible. Most attics are not set up for a fan to pull air 100% from inside the attic either. There just isn't enough venting. More times then not the air will be sucked (through a negative vaccum) from inside the home as the ceilings are poorly sealed in most homes. This creates an inefficient system and often leads to mold and moisture issues in the home. If you are concerned about the temp in your attic its better to invest in a radiant barrier for the roof/rafters as that is where the air is heating up from radiation. Like I said GD is coming out of the wood work for the almighty attic fan but you should look at the real problems first like insulation and radiant barriers. |
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Posted: 5/4/2021 11:38:07 PM EDT
[#15]
Quote HistoryQuoted: I completely disagree with your assessment. The installation of a thermostatically controlled ventilation fan five years ago, which comes on when the attic reaches 95-100 degrees, has driven down my cooling bill by AT LEAST 30%. Quote HistoryQuoted: Quoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. I completely disagree with your assessment. The installation of a thermostatically controlled ventilation fan five years ago, which comes on when the attic reaches 95-100 degrees, has driven down my cooling bill by AT LEAST 30%. That is not possible from a scientific stand point. If your bill went down by 30% something else was going on or you had other work done. Or you sell attic fans... |
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Posted: 5/5/2021 2:25:19 AM EDT
[#16]
I'm planning to put a couple of gable vents in my shop. Currently in the process of putting in insulation and closing in the ceiling.
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Posted: 5/5/2021 2:30:29 AM EDT
[#17]
Quote HistoryQuoted: That is not possible from a scientific stand point. If your bill went down by 30% something else was going on or you had other work done. Or you sell attic fans... Why do you think its not scientifically possible? The fans are simply moving air. Which is evacuating heat energy accumulated from the sun hitting the roof before it can radiate to/through the ceiling into the air conditioned space. I don't see how it necessarily violates the laws of thermodynamics. |
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Posted: 5/5/2021 4:37:01 PM EDT
[#18]
Quote HistoryQuoted: That is not possible from a scientific stand point. If your bill went down by 30% something else was going on or you had other work done. Or you sell attic fans... LOL |
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Posted: 5/5/2021 5:43:55 PM EDT
[#19]
Had a guy out today who puts in foam insulation.
My attic measured 135 degrees. The A/C ducting had a surface temp of 124 degrees. Piping cooled air through a 124 degree tube is very counter productive obviously. Oddly, I took his electro-thermo gun thing in to my living room and measured the temp of the vent itself which was 60 degrees on the surface. That surprised me because my home heats up so fast that unless I leave the A/C on 100% of the day, the temp inside will never even hit the 70's. How can a living room vent with a surface temp of 60 fail to cool my house down without ever being shut off? After seeing the 124 reading on the ducting itself, I thought for sure the air is actually being heated but it's coming out at 60 and still can't cool the house down without it running nonstop? Anyone have a take on whether the open cell foam insulation would be worth it? It would cover the entire inside of the roof of my house. I realize it would have to help but to what extent? |
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Posted: 5/5/2021 6:01:04 PM EDT
[#20]
Thought of doing a solar attic fan. The ones I see are small. I wanted to go big and move some air.
What state you in? |
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Posted: 5/5/2021 6:14:28 PM EDT
[#21]
Quote HistoryQuoted: Insulation in my attic is virtually nonexistent. Should have looked in to this before now but here I am. That is currently being addressed, likely with spray foam insulation. The exhaust fan seemed like a good idea until I read your post. Help me understand your reasoning. If the attic (hypothetically) is at 125 degrees in hot weather, and an exhaust fan is installed with a thermostat to vent hot air out, and the attic space drops in temperature, that will not affect overall house temperature? https://storage.googleapis.com/idx-acnt-gs.ihouseprd.com/AR753508/file_manager/Blog%20posts/atticventilation-1.jpg I'd guess he's thinking of a 'whole house fan' which pulls air through living space (and open windows) and out through vents in the attic. This pulls in cool evening / night air and cools the house and the attic. Had one in ventura and it worked well because nighttime temps were low enough to help. An attic fan pulls air in from some vents in the attic and out through others. Like a fan on one gable end blowing out, pulling air in from the opposite gable end to get crossflow and ventilate the space. I think better than that is good natural ventilation. Eave vents and a ridge vent. Hot air exhausts out through the ridge and pulls cooler air in through the eaves. You have to be careful with gable end vents and ridge vents. They can 'short circuit ' and not really ventilate anything. There are formulates for how much vent space you should have. Most older homes have nowhere near enough ventilation. Eta: vent space should be equall to area of attic / 150. So 1500 sf attic = 10 sf vent space. If you are using eave and ridge vents split it 50/50. 5 sf of eave vent 5 sf of ridge vent. |
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Posted: 5/5/2021 8:52:16 PM EDT
[#22]
Quote HistoryQuoted: I'd guess he's thinking of a 'whole house fan' which pulls air through living space (and open windows) and out through vents in the attic. This pulls in cool evening / night air and cools the house and the attic. Had one in ventura and it worked well because nighttime temps were low enough to help. An attic fan pulls air in from some vents in the attic and out through others. Like a fan on one gable end blowing out, pulling air in from the opposite gable end to get crossflow and ventilate the space. I think better than that is good natural ventilation. Eave vents and a ridge vent. Hot air exhausts out through the ridge and pulls cooler air in through the eaves. You have to be careful with gable end vents and ridge vents. They can 'short circuit ' and not really ventilate anything. There are formulates for how much vent space you should have. Most older homes have nowhere near enough ventilation. Eta: vent space should be equall to area of attic / 150. So 1500 sf attic = 10 sf vent space. If you are using eave and ridge vents split it 50/50. 5 sf of eave vent 5 sf of ridge vent. Quote HistoryQuoted: Quoted: Insulation in my attic is virtually nonexistent. Should have looked in to this before now but here I am. That is currently being addressed, likely with spray foam insulation. The exhaust fan seemed like a good idea until I read your post. Help me understand your reasoning. If the attic (hypothetically) is at 125 degrees in hot weather, and an exhaust fan is installed with a thermostat to vent hot air out, and the attic space drops in temperature, that will not affect overall house temperature? https://storage.googleapis.com/idx-acnt-gs.ihouseprd.com/AR753508/file_manager/Blog%20posts/atticventilation-1.jpg I'd guess he's thinking of a 'whole house fan' which pulls air through living space (and open windows) and out through vents in the attic. This pulls in cool evening / night air and cools the house and the attic. Had one in ventura and it worked well because nighttime temps were low enough to help. An attic fan pulls air in from some vents in the attic and out through others. Like a fan on one gable end blowing out, pulling air in from the opposite gable end to get crossflow and ventilate the space. I think better than that is good natural ventilation. Eave vents and a ridge vent. Hot air exhausts out through the ridge and pulls cooler air in through the eaves. You have to be careful with gable end vents and ridge vents. They can 'short circuit ' and not really ventilate anything. There are formulates for how much vent space you should have. Most older homes have nowhere near enough ventilation. Eta: vent space should be equall to area of attic / 150. So 1500 sf attic = 10 sf vent space. If you are using eave and ridge vents split it 50/50. 5 sf of eave vent 5 sf of ridge vent. Except this is S. FL and windows might be opened a combined two-three weeks a year at best. It's now 8:47pm, the sun has been down a while and it's 81 degrees outside and humid. At no point tonight will the temp outside reach a point that would match what I want it to be inside. 77 is the low.and that's for an hour or two.then back up for another cloudless day and high heat. And this is May. By August? Whew. |
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Posted: 5/5/2021 9:03:34 PM EDT
[#23]
Ridge vent. Attic fan.
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Posted: 5/5/2021 9:08:10 PM EDT
[#24]
Quote HistoryQuoted: My house has pretty airy soffits, gable vents, and lots of turtle vents. It does not get very hot. I honestly think gable vents do more work than people realize. We plan to go with steel roof with insulation under eventually, and ridge vents eventually, which will be even better. If you switch to ridge vent, make sure you cover the gable vents. |
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Posted: 5/5/2021 10:20:36 PM EDT
[#25]
Quote HistoryQuoted: Except this is S. FL and windows might be opened a combined two-three weeks a year at best. It's now 8:47pm, the sun has been down a while and it's 81 degrees outside and humid. At no point tonight will the temp outside reach a point that would match what I want it to be inside. 77 is the low.and that's for an hour or two.then back up for another cloudless day and high heat. And this is May. By August? Whew. Yeah, you're not going to want a 'whole house fan' in that situation. You need either an attic fan if you can locate it to get good through ventilation or eave / ridge vents. |
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Posted: 5/5/2021 10:30:53 PM EDT
[#26]
Quote HistoryQuoted: I ran an attic fan for decades along with radiant barrier insulation on the underside of the rafters and it beats no fan at all. However a fan pales in comparison to a full ridge vent, which was installed with a new roof, the difference is night & day. For the ridge vent to work properly you must have soffit ventilation, in my case I installed Hardi ventilated soffit panels years ago so no issues there. THIS! Ran a big PowerVent for 20 years in the attic. Replaced the motor once. It cost electric to use. When they redid the roof, they took the PowerVent and all the vent cans out. They put a full length ridge vent in everywhere there was a ridge. What a difference. What used to be absolutely unbearable up there is now just uncomfortable. |
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Posted: 5/6/2021 1:25:12 PM EDT
[#27]
Windows account for over 50% of the heating load on just about every manual J I have ever performed.
The best bang for your buck is to update your windows. If that has already been done, good attic insulation would be the second best investment. |
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Posted: 5/6/2021 2:19:50 PM EDT
[#28]
Quote HistoryQuoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. Attic fans are to allow moisture to escape. According to International Building Code 2012 (upon which many State building codes are based) a house ideally should have 5 Air Changes per Hour (ACH) or less for good energy efficiency. Houses with 3 ACH or less require mechanical ventilation to allow moisture to escape and minimize the formation of mold. ACH is measure by a Blower Door Test. If it is an older house it probably is leaky and it's hot because his conditioned air is leaking out from the windows and ceiling joists. Blowing in foam insulation in the attic would probably be cheaper then new windows but ideally both should be addressed. RESNET.us or BPI.org are the two places to start pinpointing how to best address improving the energy efficiency of a house. |
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Posted: 5/7/2021 9:48:51 AM EDT
[#29]
I'm cheap.
I would buy a solar panel and wire it directly to a fan so when the sun is shining the fan is turning. Mount the fan in the gable on the cool side blowing in, and venting thru a gable vent on the hotter side. Too simple? I'm not an expert, so I'll listen to the SMEs if they think this isn't a solution. |
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Posted: 5/7/2021 9:57:31 AM EDT
[#30]
Firemen use pike poles, axes, and maybe saws these days,
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Posted: 5/7/2021 10:08:36 AM EDT
[#31]
Quote HistoryQuoted: Had a guy out today who puts in foam insulation. My attic measured 135 degrees. The A/C ducting had a surface temp of 124 degrees. Piping cooled air through a 124 degree tube is very counter productive obviously. Oddly, I took his electro-thermo gun thing in to my living room and measured the temp of the vent itself which was 60 degrees on the surface. That surprised me because my home heats up so fast that unless I leave the A/C on 100% of the day, the temp inside will never even hit the 70's. How can a living room vent with a surface temp of 60 fail to cool my house down without ever being shut off? After seeing the 124 reading on the ducting itself, I thought for sure the air is actually being heated but it's coming out at 60 and still can't cool the house down without it running nonstop? Anyone have a take on whether the open cell foam insulation would be worth it? It would cover the entire inside of the roof of my house. I realize it would have to help but to what extent? Anyone? |
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Posted: 5/7/2021 10:49:46 AM EDT
[#32]
I answered your question already. I'm the IT guy for a construction school and not only am I certified in Building Infiltration and leakage but I am certified to issue certifications. Your conditioned air is leaking out. Plug the leaks...
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Posted: 5/7/2021 10:55:59 AM EDT
[#33]
Quote HistoryQuoted: I answered your question already. I'm the IT guy for a construction school and not only am I certified in Building Infiltration and leakage but I am certified to issue certifications. Your conditioned air is leaking out. Plug the leaks... Sorry.you replied to someone's post other than mine so I didn't see it. |
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Posted: 5/7/2021 11:00:06 AM EDT
[#34]
This thread is relevant to my interests.
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Posted: 5/7/2021 6:27:54 PM EDT
[#35]
Just had the full vent ridge installed (GAF) big difference so far. I have a gable end fan and it is kicking on less. We'll see this summer.
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Posted: 5/7/2021 6:40:21 PM EDT
[#36]
Down here a few of the builders use these.
 Some will have as many as 4 or 5 in addition to a gable vent and normal Ridge vents. |
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Posted: 5/7/2021 6:44:12 PM EDT
[#37]
Quote HistoryQuoted: The problem is most likely that the AC is run through the vented attic, where the R8 insulation on the ducts isn't enough to keep the air from warming up. The correct answer is to create a conditioned attic. Doing that is... really fucking hard. Because you basically have to roof the house again to do it right. Hold my beer. Mini splits errrryyyy where! 
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Posted: 5/7/2021 7:30:45 PM EDT
[#38]
Quote HistoryQuoted: if you’re drawing air through the house with an attic fan I can agree with you. If you’re cycling air through the attic space to effectively cool it down it has to have a positive effect on the home’s living quarter temperatures.Insulation on the attic flooring will make a big difference in your AC’s ability to keep up. Quote HistoryQuoted: Quoted: What exactly brought you to this conclusion? Windows are usually the number one culprit in a house being to warm in an A/C system house. Next is insulation. Then poor air duct routing. Then undersized units for the size of the house. Also contrary to GD myth attic fans drawing out hot air do not help keep your house cool. It actually helps drive up your energy bills and over works your A/C system. Attic fans are only good for when you want to cool your whole house using the outside air. They are a terrible idea in systems with A/C cooling. If you are trying to keep your house cool with an A/C system the last thing you want is an active attic fan creating negative pressure above the cooled areas. if you’re drawing air through the house with an attic fan I can agree with you. If you’re cycling air through the attic space to effectively cool it down it has to have a positive effect on the home’s living quarter temperatures.Insulation on the attic flooring will make a big difference in your AC’s ability to keep up. Whole house style fans are very dependent on location. There are plenty of places in CONUS that do not make it a good idea. One of the biggest issues is the humidity rise at night. Hot and damp is not pleasant. |
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Posted: 5/9/2021 11:39:51 AM EDT
[#39]
My folks have had thermostatically controlled electric fans in the attic for a long time. They seem to work well. They don't kick in until ~120F, which seems to happen when it's ~95F outside.
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Posted: 5/9/2021 5:19:21 PM EDT
[#40]
Here in Texas we definitely have heat problems. For most people it extends from multiple issues.
1) Windows and doors, replace with new high quality insulated ones. When installed, make sure the install is sealed well. 2) Walls including insulation. Make sure it is fully insulated, many older building might not have any. 3) Attic insulation. Standard is to add more blow in insulation, make sure the soffit vents are clear, and a decent amount of roof venting to allow air circulation. The remodel upgrade I'm doing next is to seal all eve vents, close off all roof venting, remove the existing crap insulation and spray foam the rafters making the attic and a/c duct area a conditioned space. |
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Posted: 5/10/2021 7:31:45 PM EDT
[#41]
Quote HistoryQuoted: Anyone? Quote HistoryQuoted: Quoted: Had a guy out today who puts in foam insulation. My attic measured 135 degrees. The A/C ducting had a surface temp of 124 degrees. Piping cooled air through a 124 degree tube is very counter productive obviously. Oddly, I took his electro-thermo gun thing in to my living room and measured the temp of the vent itself which was 60 degrees on the surface. That surprised me because my home heats up so fast that unless I leave the A/C on 100% of the day, the temp inside will never even hit the 70's. How can a living room vent with a surface temp of 60 fail to cool my house down without ever being shut off? After seeing the 124 reading on the ducting itself, I thought for sure the air is actually being heated but it's coming out at 60 and still can't cool the house down without it running nonstop? Anyone have a take on whether the open cell foam insulation would be worth it? It would cover the entire inside of the roof of my house. I realize it would have to help but to what extent? Anyone? Yes encapsulating the attic is worth it. I did mine with open cell a few years ago. The hottest my attic gets now is 86 degrees just northwest of Atlanta. It helps in many ways. 1- prevents a lot of the radiant heat coming into the attic from the roof 2- greatly decreases the air exfiltration into the attic from the house 3- because of the lower attic temp you lose much less cold air as it moves through the ductwork 4-having no fiberglass insulation in the ceiling makes running new wire a breeze. 5- there is a ga power plan here called smart usage. Power is really cheap except 2-7pm mon-Friday from June- September. Having the foam I can shutoff the ac from 2-7 & coast with it getting no warmer than 78 by 7 pm in the heat of the summer. I was so impressed when I did my detached addition I foamed the entire thing. |
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Posted: 5/10/2021 8:36:56 PM EDT
[#42]
Quote HistoryQuoted: Yes encapsulating the attic is worth it. I did mine with open cell a few years ago. The hottest my attic gets now is 86 degrees just northwest of Atlanta. It helps in many ways. 1- prevents a lot of the radiant heat coming into the attic from the roof 2- greatly decreases the air exfiltration into the attic from the house 3- because of the lower attic temp you lose much less cold air as it moves through the ductwork 4-having no fiberglass insulation in the ceiling makes running new wire a breeze. 5- there is a ga power plan here called smart usage. Power is really cheap except 2-7pm mon-Friday from June- September. Having the foam I can shutoff the ac from 2-7 & coast with it getting no warmer than 78 by 7 pm in the heat of the summer. I was so impressed when I did my detached addition I foamed the entire thing. Quote HistoryQuoted: Quoted: Quoted: Had a guy out today who puts in foam insulation. My attic measured 135 degrees. The A/C ducting had a surface temp of 124 degrees. Piping cooled air through a 124 degree tube is very counter productive obviously. Oddly, I took his electro-thermo gun thing in to my living room and measured the temp of the vent itself which was 60 degrees on the surface. That surprised me because my home heats up so fast that unless I leave the A/C on 100% of the day, the temp inside will never even hit the 70's. How can a living room vent with a surface temp of 60 fail to cool my house down without ever being shut off? After seeing the 124 reading on the ducting itself, I thought for sure the air is actually being heated but it's coming out at 60 and still can't cool the house down without it running nonstop? Anyone have a take on whether the open cell foam insulation would be worth it? It would cover the entire inside of the roof of my house. I realize it would have to help but to what extent? Anyone? Yes encapsulating the attic is worth it. I did mine with open cell a few years ago. The hottest my attic gets now is 86 degrees just northwest of Atlanta. It helps in many ways. 1- prevents a lot of the radiant heat coming into the attic from the roof 2- greatly decreases the air exfiltration into the attic from the house 3- because of the lower attic temp you lose much less cold air as it moves through the ductwork 4-having no fiberglass insulation in the ceiling makes running new wire a breeze. 5- there is a ga power plan here called smart usage. Power is really cheap except 2-7pm mon-Friday from June- September. Having the foam I can shutoff the ac from 2-7 & coast with it getting no warmer than 78 by 7 pm in the heat of the summer. I was so impressed when I did my detached addition I foamed the entire thing. Solid, supported, concise, straight forward answer. Itemized no less. Thank you. I think I'll do it. |
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Posted: 5/11/2021 8:46:31 AM EDT
[#43]
Any concerns with spraying the foam and off gassing, seems to me I recall reading something about some products off gassing for a very long time and concerns with health hazards?
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Posted: 5/12/2021 12:25:21 PM EDT
[#44]
Quote HistoryQuoted: Any concerns with spraying the foam and off gassing, seems to me I recall reading something about some products off gassing for a very long time and concerns with health hazards? the only issues I'm aware long term is when the 2 parts are not properly mixed at the nozzle and the proper chemical reaction does not occur and you are left with raw components The house should be left vacant per manufacturers timeframe during the initial cure. |
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Posted: 5/12/2021 12:35:29 PM EDT
[#45]
Quote HistoryQuoted: Anyone? What is the temp of the ceiling drywall (sample a lot of locations). You have cold air blowing through the vents, but is the ceiling radiating heat inward? |
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Posted: 5/12/2021 12:49:28 PM EDT
[#46]
Quote HistoryQuoted: What is the temp of the ceiling drywall (sample a lot of locations). You have cold air blowing through the vents, but is the ceiling radiating heat inward? Quote HistoryQuoted: Quoted: Anyone? What is the temp of the ceiling drywall (sample a lot of locations). You have cold air blowing through the vents, but is the ceiling radiating heat inward? Good question and I don't know the answer. Given the interior roof measured 135 degrees, the AC ducting 124 degrees, the ceiling drywall would have to be quite hot as well. |
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Posted: 5/12/2021 10:43:33 PM EDT
[#47]
Quote HistoryQuoted: Good question and I don't know the answer. Given the interior roof measured 135 degrees, the AC ducting 124 degrees, the ceiling drywall would have to be quite hot as well. Not if there is proper insulation between your attic and your interior. |
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Posted: 5/13/2021 2:12:52 AM EDT
[#48]
When I purchased my house, it only had gable vents and no soffit vents.
I installed soffit vents, beyond the recommend minimum surface area and it helped tremendously. I also installed an electric attic vent which I later regretted and turned off it's power. When we had a total roof shingle install, we had a ridge vent installed. That was a god send and the best combination with the soffit vents! We lived in an older house that, I installed a whirly-bird roof vent. Not even close to a comparison. Edit: I installed r15 insulation in the attic soon after our home purchase. The old blown fiberglass, I moved over to the garage space. A year later, I installed r19 fiberglass batts insulation at right angles over the r15 insulation. My home is well insulated and more sound insulated as well. 
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Posted: 5/14/2021 1:25:44 AM EDT
[#49]
Quote HistoryQuoted: I completely disagree with your assessment. The installation of a thermostatically controlled ventilation fan five years ago, which comes on when the attic reaches 95-100 degrees, has driven down my cooling bill by AT LEAST 30%. +1. Thermal mass cooling is real. Warm, dry climate here. 3-4 months ago we installed a whole house fan in attic. On high, it moves about 6000 CFM using only 200 watts. Once the sun goes down and outside air temp drops, we open windows and turn it on. It cools whole house quickly. Once morning comes, close the windows and house stays cool throughout the day. In the past, the upstairs would begin to get warm around 3PM on a hot day. Now, it stays cool past 6PM Despite 90+ degree days outside, we haven't had to run our AC once this year. The house simply stays cool due to the thermal mass effect. $375 electric bills have been cut in half. You need good insulation in attic to get the best effect from this. |
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Posted: 5/14/2021 10:20:12 AM EDT
[#50]
Quote HistoryQuoted: Once the sun goes down and outside air temp drops, we open windows and turn it on. It cools whole house quickly. Once morning comes, close the windows and house stays cool throughout the day. So I installed the whole-house fan. We get cool nights even when it's hot during the day, so we run the fan all night. In the morning after I've gone to work my wife will close the windows and blinds progressively as the sun comes up and starts hitting the house (south facing). When I get home it's hot out in the driveway, but when I go inside it feels like AC has been running. It's very manageable and she has a rigid routine that works very well. It helps that WA is very low humidity in the summer. |
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