Insulation and AC opinions/help requested


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Old 12-29-17, 07:30 PM
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Insulation and AC opinions/help requested

Hello,

I live in a 1 1/2 story home that's about 1350sf, in New Jersey. I have a 2 ton central air unit with an insulated air handler and insulated ducts in the attic. As it stands, the current unit struggles to cool the upstairs on a hot day in the summer, and it's 'ok' but not great downstairs. When the sun begins to go down it cools just fine, and on normal days its decent but not great. The delta T is acceptable generally and I had the unit checked out. It's working normally.

I am enclosing a screened in porch with knee walls and windows and adding heat/air to that space as well as insulating it. This will make my overall sf about 1450. The porch is only 100 sf, but we want it to be comfortable, so in researching how to achieve this I thought it would be a good opportunity to address the rest of the house as well, by way of insulation or mini splits or both. The insulation we currently have in the master is R13 on the sidewalls and some older thicker stuff on the attic floor under some plywood. The images go over 3 options I have gathered from various research and opinions of HVAC pros, but I am at a loss as to which way to go. Any and all opinions are greatly appreciated as this has had my head spinning for a while now.

https://i.imgur.com/iXT0ci8.jpg

https://i.imgur.com/8CuUPY6.jpg

https://i.imgur.com/GaG1p1p.jpg








 
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Old 12-30-17, 04:50 AM
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Your primary issue is low insulation, ceilings should be around R38.

Additional insulation will get the highest return up, then out, then down meaning get the ceilings and easy to get to walls done first. You can then see how that improves the situation then look at adding additional HVAC equipment.

some older thicker stuff on the attic floor under some plywood.

Compressed insulation looses R value!
 
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Old 12-30-17, 07:32 AM
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Do you recommend improving existing insulation or going the rafter/unvented route as in option 3?
 
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Old 12-30-17, 08:32 AM
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insulating the rafters isnt efficient.

I would use R13 blankets on the wall since that is an easy fix due to the room being in the attic. Then I'd put in another R20 (depends on what you have and the recommended amount for your area) of blown in cellulose for the ceilings.

See what that does next year and then make HVAC changes as needed, if needed!

At least you will have good insulation for both summer and winter needs!
 
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Old 12-30-17, 08:38 AM
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I already have R13 on the walls of the master (in green in the picture) but could do better on the floors of the attic. I suppose that would only help downstairs though right? Not so much the master cooling issue.
 
 

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