hot attic and second floor

[ap]

Hello, The past weekend, the temps in Georgia hit the upper 70s and the second floor of our 2-floor home was about 10 degrees warmer than the first floor.

Also, the attic (which houses the central a/c and heater) was extremely hot, lower 90s or so.

My question is: is this temp increase in the 2nd floor and attic normal? This is 2-story house with central A/C and heat - wooden w/ front brick.

Also, are reasonable means to cool down the attic?

There is an attic fan that was installed by the previous owner, but it kicks in around 95 F or so. Even then, not sure if it can cool down such a hot attic.

THANKS

[ap]

Hello, The past weekend, the temps in Georgia hit the upper 70s and the second floor of our 2-floor home was about 10 degrees warmer than the first floor.

Also, the attic (which houses the central a/c and heater) was extremely hot, lower 90s or so.

My question is: is this temp increase in the 2nd floor and attic normal? This is 2-story house with central A/C and heat - wooden w/ front brick.

Also, are reasonable means to cool down the attic?

There is an attic fan that was installed by the previous owner, but it kicks in around 95 F or so. Even then, not sure if it can cool down such a hot attic.

THANKS

[Joseph Meehan]

I would guess that a 20º difference on a sunny day is normal. It is hard to say for certain about your situation.

[tbasc]

The temperature differences are not unusual, as Mr. Meehan says. However, I don't think they are inevitable. Look at the Building Science Corporation web site for a discussion. TB

[SQLit]

There are several methods of "tempering" an attic. But I doubt that is what your concerned about. I live in Phoenix and attic temps can push 160F + in the summer time. (remember it is a dry heat) Even with a attic fan, temps in the summer are over 140F. My home has gable vents and turbines, still it, gets hot up there.

I suggest that you first check the amount of insulation you have installed. I added R-30 last July and August's a/c bill was 50% less. More insulation will help with the heat migrating from the attic.

The second floor will always be warmer.

Next check the air handler and all of the joints. It is not uncommon for the joints to come loose over the ages. Repair as needed.

Sorry no magic bullet for thermal dynamics.

[m Ransley]

Are you new to this house, does the second floor have a return, can some first floor supplys be cut down, you might be able to balance things out, but without a return on the second floor it will always be hot.

[mm]

Yes.

A roof fan or gable fan, right. Yes, as long as the motor is still good (not hard to replace from inside the attic, last an average of 5 or 6 years or more, although I keep thinking they should last longer.) the fan will cool down the attic, that is, it will keep it from getting so hot in the first place. I think it is the nicest thing my house has, although few people have them, and even the guy I asked before I put mine in didn't think his were much help. But I lived here before the fan, and I know it lowers the temp of my 2nd floor 10 or more degrees on a hot day. I"M in Baltimore, not as hot as Atlanta, on average.

I have a vague recollection that mine came preset to lower than 95, and it's adjustable too. I can't check right now what the setting is.

I also have a switch so I can turn off the fan in the spring and fall. This lets the attic get warmer than otherwise, and the heat heats the house a little bit. Maybe I do need more than the 6 or 8 inches of fiberglass that I have.

[buffalobill]

sometimes the attic fan is on a separate circuit. in a finished attic with a floor it's easier to find out what wattage or amperage the fan wants by reading its electrical plate. you could have your electrician wire the attic exhaust fan on a (thermostat/center off/on) three position switch on the second floor. if the fan is powerful enough it can exhaust unwanted heat from the attic and the house if the doorway to the attic is open, but depending on where it usually gets its makeup air other attic inlets may need to be closed during this cycle. stand in the attic doorway and see which way the air goes for the best ideas. look up whole house ventilation but keep any more fans up in the attic. motorized screened louvers may provide an intake in the attic. see also: