checkrdpast
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Who is the go to guy in Havasu to install attic fans?
Do the attic fans work in extreme heat?
today actual -
H 103
low 85
Well I hope it’s only like $3500 to get a good set up!It will get a little air flowing through the attic which will help. Instead of being 145 up there it will be 142
Do the attic fans work in extreme heat?
today actual -
H 103
low 85
Is he talking a whole house fan or attic fan.
Attic fan will suck air from the house and cool your attic. You pay to run the fan and more ac.
The biggest heat load in an attic is not air. It is radiant heat from the bottom of the roof to the attic floor. Evaluating that attic to house interface may give better results.
Are you saying there are no air leaks between the house and the attic? The fan puts the attic under negative pressure. It will pull air from whereever there is in opening.The attic fan typically gets its air supply from the roof vents in the sofit or vent ridge , not the air from your house.
The whole house fan pulls from the inside of your house.
Nice, how much?My last house I installed the Quiet Cool solar gable fan and the Whole house fan as well. If your in the IE or where it does not cool down enough at night then the whole house would not be for you. The gable mount you can't even here and is a VS DC brush-less motor. The Whole house ones are DC as well so they are very efficient.
Gable mount fan
Whole house fan
Are you saying there are no air leaks between the house and the attic? The fan puts the attic under negative pressure. It will pull air from whereever there is in opening.
Looking at the current air sealing standards from today versus 10-15 years ago. Also compare air sealing in very energy efficient homes compared to current codes.
The solar powered gable fan was $299 on Amazon. The 120vac smart fan is $269.Nice, how much?
I've had this same argument with him several times now. It's of no use. Aparently the faction of a CFM around each electrical and plumbing line are more important that the other open gavel or eve vents....Im saying that the attic is filled with vents already and because the path of least resistance is the existing vents - thats where the makeup air will come from - NOT from the house.
Im not saying the there are no air leaks.
It's inaccurate to say the attic fan "pulls from the house" because it primarily pulls from the attic vents.
The WHF primarily pulls from the house.
Not sure I’d bother to put one in Havasu. The day/night temps don’t vary enough during the summer months to make it worth while IMO. They work great in Sac/Inland So Cal when it’s hot as balls during the day and cool to 60’s at night.
I installed the Quiet Cool in Chino. Works really good to cool the house down when the sun goes down. I did have to put an additional gable vent in and clear/expand the soffit vents. There wasn’t enough intake and it was causing some issues. Best use is in the early am. I’ll flip it on before I leave for work. Gets cool air in the attic/house to get ready for the afternoon sun.
Lets ignore phyics and laws of thermal dynamics.I've had this same argument with him several times now. It's of no use. Aparently the faction of a CFM around each electrical and plumbing line are more important that the other open gavel or eve vents....
And when you are using it in a manner like yourself, it COMPLETELY negates his argument.
Lets ignore phyics and laws of thermal dynamics.
First off the flow of air is caused by pressure differences. If the air pressure on one side of an opening is greater than on the other air will flow.
A fan blowing out will lower the pressure in the entire attic. Will this pressure be equal in all areas of the attic? No, closet to the fan will have the lowest pressure.
More air will flow from larger openings. But air will flow through all opening that have a higher pressure. Many of the small openings will be nearer the fan and see a higher negative pressure. The total area of small leaks could be as great as vents.
Some air handlers can put a home in a positive pressure state now you are helping it push more air out.
If you have air ducts and an air handler in the attic. These can be a little leaky or a lot leaky.
Now lets get into thermodynamics. Can we agree hot air rises. If your attic is properly vented then the hot air flows up and out. Are you saying that hot air is also flowing down into the house? Radiant heat flows through the air. The greater the ∆t is the more radiant heat flow. The underside of the sheathing is the hottest surface. If you could see randiant heat is would be like shining a spot light from the bottom of the sheathing on to the insulation. The hotter the roof the brighter this light would be.
Since radiant heat is primary then cooling the air has little effect. A radiant barrier can be used to block radiant heat. Materials are cheap but labor is expensive. Also the more insulation you have the less effective it becomes. Insulation creates a barrier for conductive heat flow and also radiant heat flow.
I will take my information from guys like Joseph Lstiburek Ph.D., P.Eng., ASHRAE Fellow
Principal, Building Science Corporation. People who study and test versus the guy down the street.
From this old house
One reason that attic fans are inefficient is that they rely on the existing attic vents (at the soffits, ridge, or gables) to make up the air they exhaust. Usually, these attic vents are not designed for this purpose, and they may not be able to supply enough replacement air. That can put the attic at a lower pressure than the upper floor of the house, which sucks conditioned air into the attic through holes for recessed lights, attic stairs, whole-house fans, and the like.
Conditioned air can also be sucked directly out of unsealed ducts in the attic. In this situation, adding attic fans can cost you more cooling dollars than not having a fan.
H
Don’t Let Your Attic Suck - Power Attic Ventilators Are a Bad Idea - Energy Vanguard
Trade shows can be both educational and infuriating, and there’s one product I see at a lot of trade shows that fits easily into the latter category – power attic ventilators. The variety of this device that’s been popular lately…www.energyvanguard.com
Lets ignore phyics and laws of thermal dynamics.
First off the flow of air is caused by pressure differences. If the air pressure on one side of an opening is greater than on the other air will flow.
A fan blowing out will lower the pressure in the entire attic. Will this pressure be equal in all areas of the attic? No, closet to the fan will have the lowest pressure.
More air will flow from larger openings. But air will flow through all opening that have a higher pressure. Many of the small openings will be nearer the fan and see a higher negative pressure. The total area of small leaks could be as great as vents.
Some air handlers can put a home in a positive pressure state now you are helping it push more air out.
If you have air ducts and an air handler in the attic. These can be a little leaky or a lot leaky.
Now lets get into thermodynamics. Can we agree hot air rises. If your attic is properly vented then the hot air flows up and out. Are you saying that hot air is also flowing down into the house? Radiant heat flows through the air. The greater the ∆t is the more radiant heat flow. The underside of the sheathing is the hottest surface. If you could see randiant heat is would be like shining a spot light from the bottom of the sheathing on to the insulation. The hotter the roof the brighter this light would be.
Since radiant heat is primary then cooling the air has little effect. A radiant barrier can be used to block radiant heat. Materials are cheap but labor is expensive. Also the more insulation you have the less effective it becomes. Insulation creates a barrier for conductive heat flow and also radiant heat flow.
I will take my information from guys like Joseph Lstiburek Ph.D., P.Eng., ASHRAE Fellow
Principal, Building Science Corporation. People who study and test versus the guy down the street.
You don't get it at allLets ignore phyics and laws of thermal dynamics.
First off the flow of air is caused by pressure differences. If the air pressure on one side of an opening is greater than on the other air will flow.
A fan blowing out will lower the pressure in the entire attic. Will this pressure be equal in all areas of the attic? No, closet to the fan will have the lowest pressure.
More air will flow from larger openings. But air will flow through all opening that have a higher pressure. Many of the small openings will be nearer the fan and see a higher negative pressure. The total area of small leaks could be as great as vents.
Some air handlers can put a home in a positive pressure state now you are helping it push more air out.
If you have air ducts and an air handler in the attic. These can be a little leaky or a lot leaky.
Now lets get into thermodynamics. Can we agree hot air rises. If your attic is properly vented then the hot air flows up and out. Are you saying that hot air is also flowing down into the house? Radiant heat flows through the air. The greater the ∆t is the more radiant heat flow. The underside of the sheathing is the hottest surface. If you could see randiant heat is would be like shining a spot light from the bottom of the sheathing on to the insulation. The hotter the roof the brighter this light would be.
Since radiant heat is primary then cooling the air has little effect. A radiant barrier can be used to block radiant heat. Materials are cheap but labor is expensive. Also the more insulation you have the less effective it becomes. Insulation creates a barrier for conductive heat flow and also radiant heat flow.
I will take my information from guys like Joseph Lstiburek Ph.D., P.Eng., ASHRAE Fellow
Principal, Building Science Corporation. People who study and test versus the guy down the street.
Now come on!! Quit using math and logic here!!Assuming centric computed the WHF ceiling box to be able to flow the rated 6500 CFM and they rated the attic fan at 1500 CFM.
My attic has 10X the space in vent openings (or more) than the size of that ceiling damper box
Im finding it hard to believe a mere 1500 CFM fan is going to be able to pull negative pressure beyond these local vents much if at all - if I have leaky ducts Ok- sure.
Whats the HVAC guys proper and correct measurement of vent opening size to CFM flow ?
Now come on!! Quit using math and logic here!!
I can't tell you from them being installed, BUT we had Anderson windows out awhile back for an estimate. through their demonstrationHow much to windows play into home cooling ?
Window companies say it's a big deal HVAC companies say windows do very little.
Any real word examples of how much good windows help ?
I'm in So Cal never ever run the heater but the AC runds from July-Sept.
How much to windows play into home cooling ?
Window companies say it's a big deal HVAC companies say windows do very little.
Any real word examples of how much good windows help ?
I'm in So Cal never ever run the heater but the AC runds from July-Sept.
Look up Fourier's Law. It is the calculations for heat transfer through a wall. One of the LARGEST integers in the formula is the Delta T value. The difference between the 2 different sides of the wall. This is ambient temp, AKA air temp. It is common on 100+ degree days for a standard attic to get up to 140+ degrees (I know, I used to have to work in them). If you have a interior space of 76, that gives you a multiplier of 64 degrees. Now, if you can install an attic fan in a properly ventilated attic and reduce that attic temperature down to 110 - 120, your multiplier has now dropped 20 to 30 degrees. That is a MASSIVE load difference.Lets ignore phyics and laws of thermal dynamics.
First off the flow of air is caused by pressure differences. If the air pressure on one side of an opening is greater than on the other air will flow.
A fan blowing out will lower the pressure in the entire attic. Will this pressure be equal in all areas of the attic? No, closet to the fan will have the lowest pressure.
More air will flow from larger openings. But air will flow through all opening that have a higher pressure. Many of the small openings will be nearer the fan and see a higher negative pressure. The total area of small leaks could be as great as vents.
Some air handlers can put a home in a positive pressure state now you are helping it push more air out.
If you have air ducts and an air handler in the attic. These can be a little leaky or a lot leaky.
Now lets get into thermodynamics. Can we agree hot air rises. If your attic is properly vented then the hot air flows up and out. Are you saying that hot air is also flowing down into the house? Radiant heat flows through the air. The greater the ∆t is the more radiant heat flow. The underside of the sheathing is the hottest surface. If you could see randiant heat is would be like shining a spot light from the bottom of the sheathing on to the insulation. The hotter the roof the brighter this light would be.
Since radiant heat is primary then cooling the air has little effect. A radiant barrier can be used to block radiant heat. Materials are cheap but labor is expensive. Also the more insulation you have the less effective it becomes. Insulation creates a barrier for conductive heat flow and also radiant heat flow.
I will take my information from guys like Joseph Lstiburek Ph.D., P.Eng., ASHRAE Fellow
Principal, Building Science Corporation. People who study and test versus the guy down the street.
What HVAC guy doesn't say windows play a huge role? They play a MASSIVE role. Specially depending on their orientation (North, West, East, South). I could do heat load calcs to illustrate, but just don't quite have the time ATM.How much to windows play into home cooling ?
Window companies say it's a big deal HVAC companies say windows do very little.
Any real word examples of how much good windows help ?
I'm in So Cal never ever run the heater but the AC runds from July-Sept.
A bunch.
Every trade is at odds with the others in regards to getting available budgets.
The window guy will always tell you you'll need less AC with better windows, and the HVAC guy will tell you a bigger better variable speed and capacity system installed with his knowledge will return a better ROI than the windows.
Everything matters and it all adds up.
I just did windows in LA and it made a huge difference.
I'm waiting a bid for windows at the moment. As you know i'm also collecting bids for Solar and looking into the attic as well.
Does it make sense to do the windows make sure the attic is properly insulated and ventilated to get better Electricy usage numbers before going Solar?
Yeah It's not a fun purchase at all but at some point I have to reign in the utilty bills. I average $400 from SCE this month will be $650The lower you get your usage the faster ROI you will get from the solar investment.
Windows and solar is going to be brutal but they are smart moves that will pay off over time.
You are adulting hard here sir.
Im similarly spending large on home projects myself when a new truck would be far more fun.....
I know we started out on attic fans But about 7 years ago when we averaging over 850 a month for the year. Had my mother in law living with us. Oxygen generator. 3 special braille teadimg lights on almost 24 /7. Old ac. Had to lease my solar cause tough times I couldn’t afford buy then.Yeah It's not a fun purchase at all but at some point I have to reign in the utilty bills. I average $400 from SCE this month will be $650
The windows are still a maybe but I'm 95% sure the solar is going to happen.
I know we started out on attic fans But about 7 years ago when we averaging over 850 a month for the year. Had my mother in living with us. Oxygen generator. 3 special braille trading lights on almost 24 /7. Old ac. Had to lease my solar cause tough times I couldn’t afford buy then.
Anywho. MIL has passed and new AC from riverbound. Still have old school pump for the pool. But long story longer. My solar lease is a little over 200 (39 panels) forget the output. And I still am paying Edison now in some about 125. But still a hell of a long way 850 average or over 1k for the last two months.
I would say solar is your priority from my experiences
Have baysilhayden read over the proposal if possible. I know many companies quote the absolute highest possible output numbers from the panels and not the realistic numbers (cloud cover, dusty panels even when kept up, shadows, etc).Yeah If the solar produces what they say ( 18,000-19,000 kWh ) then it will cover all of my other energy sins like old HVAC, bad windows and ols school pool pump. I currently use a little over 16,000 kWh
Yeah If the solar produces what they say ( 18,000-19,000 kWh ) then it will cover all of my other energy sins like old HVAC, bad windows and ols school pool pump. I currently use a little over 16,000 kWh
I was gonna say that as well. I think I’m “only” 12-13 kWH. With 39 panels.Yowsa thats some juice, how many panels and which inverters are you looking at?