The Field Guide to GPCH33631 Installation Prep: Picking the Spot, Getting Level & Nailing Your Clearances

Hey—it’s Jake.

Before you get all excited and start running refrigerant lines, you’ve gotta lay the groundwork. And I mean literally. The Goodman GPCH33631 is a beautiful beast of a horizontal AC unit, but it’s not gonna run right if you plop it down wherever the mood strikes. Site selection, leveling, and proper clearances are where installs are won or lost.

I’ve seen too many jobs where someone “eyeballed” the pad, squeezed the unit into a corner, or forgot to plan for condensate drainage. You know what that gets you? Noise complaints, efficiency loss, service calls, and in one case… a very angry raccoon. 🦝 Long story.

So let’s do this right.

 

Why Site Selection Matters for the GPCH33631

The GPCH33631 is a horizontal package unit with 3 tons of cooling power—it’s not exactly a wallflower. Pick the wrong spot and you’ll be fighting airflow issues, noise problems, and maybe even code violations.

Think of site selection as setting the stage. You want:

• Clear, unrestricted airflow to the intake and exhaust sides

• Stable, level ground or a properly installed support system

• Easy access for service and maintenance

• Safe routing for electrical and refrigerant lines

• A spot that meets the manufacturer’s clearance requirements

For a deeper dive into why placement affects performance, Energy.gov’s central air conditioning overview is worth a read—it backs up what I’m telling you here.

 

Scouting the Best Spot

When I’m scoping out an install site for a horizontal unit like the GPCH33631, I run through a quick checklist:

1. Distance from Living Spaces – Keep it away from bedrooms and main living areas to minimize noise complaints. Even though Goodman builds them pretty quiet, airflow still moves air—and air makes noise.

2. Drainage Considerations – This is huge. Horizontal units produce condensate, and you need that draining away from the foundation. If water pools, you’re in trouble.

3. Sun & Shade – Shady spots help the unit run more efficiently. If you can put it under an overhang or on the north side of a building, that’s even better.

4. Wind Patterns – Crosswinds can mess with coil airflow. Avoid placing the discharge side directly into prevailing winds if possible.

5. Access for Service – You’ll need space to remove panels, replace parts, and do annual maintenance without disassembling half the building.

 

Clearance Requirements You Can’t Ignore

Goodman specifies exact clearance distances for a reason. On the GPCH33631, you’ll typically need:

• Around 36 inches (3 feet) clearance on the coil sides

• At least 60 inches (5 feet) above for vertical airflow discharge

• 24 inches minimum on the service access side

• Nothing blocking the return air path

You might be tempted to “just squeeze it in” somewhere tighter—but you’ll be cutting efficiency and making service a pain. In fact, restricted airflow is one of the leading causes of high head pressure and compressor failure.

The Air Conditioning Contractors of America lays out airflow standards that prove why this matters—too little space, and your system works harder, draws more amps, and burns out faster.

 

The Art of Leveling the GPCH33631

Now here’s where a lot of installs get sloppy. Leveling isn’t just “close enough”—it’s mission-critical.

A horizontal unit like the GPCH33631 needs to be level side-to-side and slightly pitched toward the condensate drain. Why? Because:

• If it’s off-level, the compressor oil can pool in the wrong spots, starving bearings

• Uneven evaporator coil surfaces cause refrigerant distribution problems

• Improper pitch can back up condensate and flood the pan

I use a 24-inch level and shims to get the base perfect. On concrete pads, I’ll pour a self-leveling compound if needed. For rooftop installs, adjustable legs or hangers are your friend—just make sure they’re rated for the unit’s weight plus vibration load.

If you’ve never done precision leveling before, check out Builder Magazine’s install best practices—they’ve got some excellent tips for keeping things square.

 

Ground Mount vs. Rooftop Install

This unit can be mounted either on the ground or on a flat rooftop. Each has its quirks:

• Ground Mount: Easiest for service, but you’ve gotta prep for drainage and protect against ground frost heave if you’re up north. Concrete pads are best.

• Rooftop: Saves space and often improves airflow, but you’ll be dealing with structural load checks, crane lifts, and waterproofing roof penetrations.

For rooftop installs, the National Roofing Contractors Association has guidelines for keeping penetrations watertight and avoiding roof damage.

 

Pad Selection Tips

If you’re going ground-mount, don’t just grab any slab from the home store. Look for:

• UV-stable composite or fiber-reinforced pads

• Ribbed undersides to resist shifting

• A footprint that matches or slightly exceeds the unit base

• Anti-vibration properties if near living spaces

Pro tip: I often elevate pads slightly with compacted gravel underlayment—it helps drainage and discourages critters from nesting under there.

 

Planning for Future Maintenance

When you’re choosing your site and clearances, think about the Jake of the future (or whatever tech is coming in for service). You want:

• Room for gauges to connect to service ports without contorting like a gymnast

• Easy access to remove blower or coil panels

• Enough light (or a nearby power source for a work light)

• Safe ladder access if on a roof

The number of installs I’ve seen that are technically “in spec” but a nightmare to work on… let’s just say those jobs always end with a few choice words.

 

The Safety Factor

Don’t forget local code compliance and safety clearances around gas lines, dryer vents, and electrical service. If in doubt, always check with your local inspector before finalizing the spot.

And if you’re not sure about your refrigerant handling, you can brush up on the EPA’s HVAC safety practices. Not glamorous, but important.

 

Jake’s Quick Checklist Before Install Day

• Site is clear, level, and stable

• Clearances meet or exceed Goodman’s spec

• Drainage slope is correct

• Electrical route is safe and code-compliant

• Service access is easy and unobstructed

• Future maintenance considerations accounted for

 

Final Thoughts From Jake

That’s it—you’re now officially ready to give your GPCH33631 a home it deserves. If you do this prep right, the actual install is way smoother, and you avoid half the headaches that come from poor placement.

If you need the full specs or want to see the unit you’re working with, check out the Goodman GPCH33631 product page so you’ve got the manufacturer’s info right in front of you.

Need some electrical tips for this unit? Visit my guide: The No-Nonsense Guide to Wiring the GPCH33631 Without Getting Zapped or Failing Inspection.

Now grab a drink, sit back, and enjoy the fact that you’re about to install this thing like a total pro. Cheers, Jake 🍻