What We Look For (And What We Don’t): Cooling Systems — Testing, Limitations, and What’s in Scope

The first thing most people ask in summer: “Does the A/C work?” And fair enough—if you're touring homes in July, that cool blast of air matters. So during the inspection, I absolutely test the cooling system. But here’s the truth: I’m not an HVAC tech. I’m here to verify operation, not rebuild the compressor in your driveway.

Cooling Systems I Commonly Inspect

Here’s what I’m trained to inspect—and how I approach it:

Central air conditioning – I activate it using the thermostat (if weather permits), confirm the system runs, and check for cold airflow at supply vents. I also inspect the exterior condenser unit visually.
Heat pumps (in cooling mode) – Same process as central A/C. These may also serve as your heating system, depending on setup.
Mini-split systems (ductless) – I test each head unit (wall-mounted unit) for operation and cool airflow.
Wall A/C units – Tested for operation and airflow, if accessible and plugged in.
Swamp coolers / evaporative coolers – These are common in dry climates. I confirm they turn on and blow air, but I don’t test pad condition, water flow, or drain systems.

What I’m Looking For—And What I’m Not

✅ I’m looking for: systems that activate with the thermostat, air that feels cool at vents, unusual noises, water discharge from condensate lines, and condenser unit condition.
❌ I’m not looking to: measure refrigerant pressure, dismantle the unit, remove panels, verify SEER ratings, or confirm BTU performance. That’s a job for an HVAC tech.

Weather and Safety Limitations

If it’s cold outside, I won’t run the A/C. Why? Running cooling systems below ~60°F can damage the compressor. In that case, I’ll note the limitation and recommend that the buyer test the system as soon as outdoor temperatures allow.

How I Use Thermal Imaging to Verify Cooling

I often use a thermal camera or laser thermometer to compare return and supply temperatures. This helps verify that the system is actually cooling—not just making noise. A 15–20°F difference between return and supply is typically a good sign.

About Swamp Coolers (Evaporative Coolers)

If you're from a humid climate, you might not have seen one before. Evaporative coolers are common in dry regions. They work by blowing air across a wet pad to cool the space. They’re not true A/C—they don’t use refrigerant, and they struggle in humid conditions.

I’ll confirm operation if the unit is on and accessible, but I won’t test water flow, pad condition, or duct routing. Those systems are quirky, and they require specific maintenance that’s outside the scope of a general home inspection.

FAQs: Cooling System Inspection

Do you test the air conditioner?

Yes—if weather and access allow. I activate the system using normal controls and check for cool airflow from vents or wall units.

Can you tell if the A/C is low on refrigerant?

No. That requires specialized gauges and training. If the system runs but doesn’t cool properly, I’ll recommend an HVAC evaluation.

Why won’t you test the A/C when it’s cold outside?

Running an A/C system in cold weather can damage the compressor. If it’s below 60°F, I’ll document the limitation and explain next steps.

Do you test swamp coolers?

I test basic function—turning it on and verifying airflow. But I don’t assess water distribution, pad condition, or deeper system mechanics.

→ Next up: Post 19: Ducts & Vents — The Forgotten System That Impacts Your Comfort

← Previously: Post 17: Heating Systems — From Pilot Lights to Furnace Filters

Curious what it’s like to schedule your own home inspection with us?