Understanding Your Home’s AC System & Its Inspection Limitations in Winter
A well-functioning air conditioning (AC) system is essential for home comfort, particularly during the warm months. As a home inspection company, we often receive questions about how an AC system works and what limitations exist when inspecting it during the winter. In this blog, we’ll break down the basics of how an AC system operates, what we look for during an inspection, and why winter conditions can impact a full evaluation.
How an AC System Works
A home’s air conditioning system is designed to remove heat from inside the house and release it outdoors, keeping the indoor environment cool and comfortable. This process involves several key components:
1. Thermostat
The thermostat acts as the control center, allowing homeowners to set their desired temperature. It signals the AC system to turn on or off based on the home’s temperature.
2. Evaporator Coil (Indoor Unit)
Located inside the home, the evaporator coil absorbs heat from the indoor air. This coil contains refrigerant, which changes from a liquid to a gas as it absorbs heat, cooling the air that is then circulated back into the home.
3. Compressor (Outdoor Unit)
The compressor is often considered the heart of the AC system. It pressurizes the refrigerant and moves it between the indoor and outdoor units.
4. Condenser Coil (Outdoor Unit)
After the refrigerant absorbs heat inside, it travels to the condenser coil outside, where the heat is released into the outdoor air. The refrigerant then returns to its liquid state and cycles back inside.
5. Expansion Valve
This component regulates the flow of refrigerant into the evaporator coil, ensuring that it can effectively absorb heat.
6. Air Handler & Blower
The air handler works alongside the blower fan to distribute cooled air throughout the home via ductwork and vents.
This cycle continues until the thermostat detects that the indoor temperature matches the desired setting.
How Home Inspectors Evaluate an AC System
During a home inspection, we assess the AC system’s condition and performance by examining:
✔ Exterior Unit (Condenser): Checking for visible damage, debris buildup, and proper airflow.
✔ Refrigerant Lines: Looking for insulation issues or leaks.
✔ Air Filters & Ductwork: Ensuring clean filters and checking for leaks or blockages in the ducts.
✔ Thermostat Function: Confirming the system responds properly to thermostat adjustments.
✔ Electrical Connections: Inspecting wiring for safety hazards or loose connections.
However, when performing an inspection in winter, there are limitations to how thoroughly we can evaluate the AC system.
Why AC Inspections Are Limited in Winter
In cold weather, running a central air conditioning system can actually cause damage. Most manufacturers recommend that AC systems should not be operated when outdoor temperatures are below 60°F (16°C). Here’s why:
1. Risk of Damage to the Compressor
The AC compressor relies on oil for lubrication. In cold temperatures, this oil thickens, which can cause excess wear or even damage to the compressor if the system is forced to operate.
2. Inaccurate System Performance Readings
Because AC systems are designed to function in warm conditions, testing them in winter does not provide an accurate reflection of their cooling performance. The refrigerant pressures and airflow measurements won’t align with normal operating conditions.
3. Manufacturer Warranties May Be Voided
Many AC manufacturers include a clause in their warranties stating that running the system in cold temperatures can void warranty coverage. This is another reason why professional home inspectors will not test AC cooling modes during winter inspections.
What Homebuyers & Sellers Should Know About Winter AC Inspections
While we can’t fully test an AC system in the winter, there are still important steps we take to assess its condition:
🔹 Visual Inspection: We check the condenser unit for physical damage, rust, or debris buildup.
🔹 Ductwork & Airflow Inspection: Ensuring vents are unobstructed and ductwork is properly sealed.
🔹 Age & Maintenance History Review: Checking the system’s age and looking for service records can provide insight into its condition.
For homebuyers purchasing a property in winter, we recommend having the AC system fully tested by an HVAC professional once temperatures warm up. Sellers can also provide recent service records or have a pre-listing inspection done in the fall to reassure buyers about the system’s condition.
Your AC system plays a crucial role in home comfort, and regular maintenance is key to ensuring it runs efficiently. While winter inspections have limitations, an experienced home inspector can still evaluate the system’s overall condition and identify potential concerns. If you’re buying or selling a home this season, understanding these limitations can help you plan accordingly.
For a professional home inspection that provides thorough insights into your home’s systems, contact us today – 203-387-2131.