Heights home AC systems (Houston, Marlin: apartment, house, construction)

[FlyingTexan1]

I bought a 1950 bungalow, slab, and curious what tonnage your AC system is and what size your home is. My home is 1240 sq feet. Wondering if 2.5ton is enough, I plan on adding insulation.

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[jasonamd]

All depends on the construction and energy efficiency of the house. Best thing to do is to have a manual j load calculation done and it will tell you exactly what size you need after you do any upgrades to insulation. I have a energy star home at 1900 sqft with a 3 ton system. 2.5 ton is probably about right for the age and size of your home.

[Marlin84]

Originally Posted by FlyingTexan1

I bought a 1950 bungalow, slab, and curious what tonnage your AC system is and what size your home is. My home is 1240 sq feet. Wondering if 2.5ton is enough, I plan on adding insulation.

Sent from my EVO using Tapatalk 2

My advice would be to do it right. Going too small will stress the system and kill your electricity bill, going too large will cool the house too quickly without being able to dehumidify.

I lived in an apartment with a system that was woefully undersized. During the summer it could not cool my apartment to any less than 78 degrees. It would run non-stop and finally cool to 74-75 around 2 or 3 AM.

Have a heat calc. done and be glad you did, especially in Houston.

[jasonamd]

Originally Posted by Marlin84

My advice would be to do it right. Going too small will stress the system and kill your electricity bill, going too large will cool the house too quickly without being able to dehumidify.

I lived in an apartment with a system that was woefully undersized. During the summer it could not cool my apartment to any less than 78 degrees. It would run non-stop and finally cool to 74-75 around 2 or 3 AM.

Have a heat calc. done and be glad you did, especially in Houston.

Partially true. A system running longer and cycling less often is more efficient and less stressful than a system that starts and stops often. A system that short cycles will cause humidity issues and actually cost more in electricity. You want the system to be running for longer than 10-15 minutes at a time to properly control humidity and reach peak efficiency. Anything less than that and your system is running less efficient and will not control humidity.

I believe the system design temp for Houston is around 96 degrees. Meaning when it is 96 degrees a properly designed system will maintain an indoor temperature of 78. To do this the system will run continuously. Of course, most all systems are slightly oversized.

[Marlin84]

Originally Posted by jasonamd

I believe the system design temp for Houston is around 96 degrees. Meaning when it is 96 degrees a properly designed system will maintain an indoor temperature of 78.

That is too hot.