Learning Center
Comfort by Space
AC for every space in your Phoenix home — a hot upstairs, a bonus room over the garage, a garage or workshop, a sunroom, whole-home zoning, and new-construction vs. retrofit. The honest fix is rarely a bigger AC.
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7 plain-language guides on comfort by space, written for Phoenix homes.
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AC for Every Space in Your Phoenix Home
Different spaces fail to cool for different reasons — and the answer is rarely a bigger AC. Here's how RM III diagnoses each hard-to-cool space in a Phoenix home, and the honest fix for each.
6 min read →
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Why Your Upstairs Bedroom Is Hot in Phoenix
A hot upstairs while downstairs is fine is the classic Phoenix two-story problem. Here's what really causes it — heat, attic, and starved ducts — and the fixes that actually work.
5 min read →
learn
Cooling a Bonus Room Over the Garage
A room over the garage is one of the hardest spaces to cool in Phoenix. Here's why it bakes — heat from below and starved ducts — and why a mini-split usually beats upsizing.
5 min read →
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Cooling a Garage or Workshop in Phoenix
Turning a Phoenix garage or workshop into a usable space means beating an enormous heat load. Here's why a mini-split plus insulation works — and why extending your central ducts doesn't.
5 min read →
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Cooling a Sunroom or Arizona Room in Phoenix
A sunroom or Arizona room is mostly glass — a solar heat trap in Phoenix. Here's why your central AC can't keep it comfortable, and the right-sized mini-split-plus-shading fix that can.
5 min read →
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Whole-Home Zoning for a Phoenix House
If parts of your home are always too hot or too cold, zoning may be the answer. Here's how HVAC zoning compares with a multi-zone mini-split and a duct correction for a Phoenix home.
6 min read →
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New-Construction vs. Retrofit HVAC in Phoenix
Designing HVAC for a new build is a different job from retrofitting an existing home. Here's how the two compare in Phoenix — load calcs, duct design, zoning, and the honest trade-offs.
6 min read →