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Discussion Starter · #1 ·
clients second floor is very hot ,
its one of those second floors where the ceiling is the actual roof pitch.
so , you can gain access to the enclosed part of the attic through doors on the side walls.
they only used r-11 insulation in the roof. also the a/c unit is in the attic
the walls are just framing , and t&g , with r-11 on them too , but the door ways are just wood with no insulating factor on them at all.

that second floor is easily 10-15 degrees warmer than the first floor ( we`re in Miami)
they have a wall unit a/c unit running all the time upstairs , but it does nothing
whats best?
heavier insulation?
one of those Power Attic Ventilators?
if I use one of these do I have to have an opening on the other end , so there is cross ventilation?
they have one turbine up there now, but its doesn`t seem to be doing enough.
I`d hate to spend their time and money , and find it didn`t help
 

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Eater of sins.
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The problem with the "attic" and second floor being so hot is not because of lack of venting hot air out. Though the venting may still be a problem for moisture issues.
It is getting hot because of radiant energy and heat conduction, most probably.
Sounds like a radiant barrier is not in the cards though from you description.
More insulation, maybe spray foam if possible is your best bet.

Andy.
 

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Discussion Starter · #4 ·
so , don`t bother with one of those electric , or thermostat controlled exhaust fans?
just put more insulation?
 

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You need to air seal the room from the attic area. The access doors are essential. If you put a power vent to pull the hot air out, it will just take the cold air from the house also. Foam or rubber seal it, put rigid foam on the back of the door(s) if budget allows and add as much insulation to any areas that you can. Yes, if you add a power vent, you must give the air an entry point. The lower in the roof line the better. The soffit would be preferred, if not then vented drip. The also needs to be room for the air to move in each bay, so install baffles under the roof sheathing if you can.
 

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Eater of sins.
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so , don`t bother with one of those electric , or thermostat controlled exhaust fans?
just put more insulation?
I am not trying to say what you should or should not do. Put in the fan if you want, I don't think it will do any good from my very limited understanding of your situation though.
Radiant barrier in your location is a good idea if they can be used effectively, it doesn't sound like you would have the required distance between RB and anything that might contact it though.

A cool roof would help, a radiant barrier would help and more insulation would help also. By code you can put rigid or spray foam tight to the underside or the top of deck. All good things if possible.

Andy.
 

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Discussion Starter · #8 ·
your helping
right now there is blown in laying on the bottom of the attic ( not allot , and it looks old), and then there is r-11 . fastened to the underside of the roof deck.
should I just double up on everything?
and also insulate the hell out of that wall dividing the attic from the second floor?( along with sealing that door)
 

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If I am understanding this correctly there is insulation in the rafter bays and not much blown in on the floor of the attic/ceiling of the room? If so, the insulation in the ceiling matters a LOT more than the fiberglass in the rafter bays. Add the fan only if you can pull the air from the lower portion of the roof. If thats not possible then your next best option would be a gable end fan on one end with a vent on the other for the intake. Depending on how the blown in is done, I would pull it back at any fan or light openings, spray foam around the boxes with fireblok and any other openings. Then lay R30 (cheapest/best option where I am) unfaced rolls across the floor of the entire attic.
 

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really ?
you wasted time sending this?
I wonder if clouds look down , and say
" look , that ones looks like an idiot!"
I don't know what pissess me off more, that I feel that I have to explain myself or that I "think" you just called me an idiot.

My original reply was asking your location because I missed it in my first reading. After I replied, I noticed your location as Miami. I couldn't delete my reply, so I did the only thing that I could do which was replace the question with "...".

I actually have a good friend who is an HVAC guy that I was planning to get his thoughts on your issue. Now. Not so much.

Good luck.
 

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Venting.....venting...venting.....................and proper venting.

I just (last summer, to be honest) installed a cupola and full perimeter soffit vents in my old house, and finally got around to actually cutting out the roof under the cupola to vent the "attic"space last week.

My second floor was at least 20 deg. hotter than my first......now, it is at least 5 deg. cooler.

Made all the difference in the world. I still need to air seal and beef up the 6-8" of cellulose in my lid before winter comes......but JUST the venting has changed my life.

Whole house fan is next (to suck that cool night air in during those couple tropical weeks).

Just get the 140 deg air out.....and the rest is elementary.
 
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Ventelation is key. Is there a ridge vent already? Soffit vents, baffles? Gable vents?

Spray foam would be cool, but cellulose on the ceiling, additional venting.
 

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Capra Aegagrus
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I'm confused. It sounds like you're describing an attic space with kneewalls, but then you go on to say the air conditioner is in the attic.

Whatever. On a 90° day, what's the temperature in the attic? If you have adequate ventilation, it shouldn't be excessively higher. R11 isn't a lot of insulation.
 

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Sean
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You don't need to cool down or vent the attic, you need to block / slow down the heat transfer from coming in from he attic / cathedral areas to where the AC can handle it & that would be by insulating & air sealing the areas properly
As for the best method - well that mainly revolves around what one can afford to spend & do - Cadillac method, go with a hot roof system
 

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Discussion Starter · #17 ·
I'm confused. It sounds like you're describing an attic space with kneewalls, but then you go on to say the air conditioner is in the attic.

Whatever. On a 90° day, what's the temperature in the attic? If you have adequate ventilation, it shouldn't be excessively higher. R11 isn't a lot of insulation.
you go up stairs , the ceiling of that room is the roof line ,( its basically t&g on the roof pitch , I don`t know if that's insulated.
the walls on 2 sides have 4x4 doors that open up to attic space that is at the same level as the room.
so one the right wall theres a door going into attic space , which is abour 30 x 15 feet , and the same on the left side.
you walk into that attic space , and its got the r-11 on the top , right under the roof deck , and blown in on the floor ( which is the downstairs ceiling)
the divider wall between the second floor and that attic space is 2x4, with t&g, with r-11 stapled to it, some of it has fallen loose.
that 4x4 door is just 2X4`S with t&g also ,no insulation on it, and not close to sealed, it just clips closed with a hasp.
 

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Discussion Starter · #18 ·
I don't know what pissess me off more, that I feel that I have to explain myself or that I "think" you just called me an idiot.

My original reply was asking your location because I missed it in my first reading. After I replied, I noticed your location as Miami. I couldn't delete my reply, so I did the only thing that I could do which was replace the question with "...".

I actually have a good friend who is an HVAC guy that I was planning to get his thoughts on your issue. Now. Not so much.

Good luck.
LOL,it basically looked like you were an Angies List associate , fishing for clients .
you didn`t give advice , just a cute saying , so I shot one back,
lets not ruin our relationship , we never fought before this.
I see you did send advice after that , thanks.
 

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Pictures... pictures...
You can never cool your roof cooler than ambient air, unless you are using cooler house air to do it, which is just a waste of money.

If its miami, and its 100 degrees outside, the BEST you can expect, is to cool it down to 100 degrees. The roof surface temp can be 150, but with proper ventilation, you can lower that much lower and closer to ambient.

But you need adequate attic air flow- and air exchange. Then the rest is about insulation- how quickly heat gets radiated into the living space, and preventing as much of the heat of the roof to penetrate into into the attic in the first place.

Reflective barriers are an option.

BTW, if they have central AC, and no thermal operated attic fan (and proper air flow),they are probably throwing hundreds of dollars away every year.
 
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