AC Replacement? When homeowners compare system replacement quotes, prices can vary — sometimes by thousands of dollars.
That’s because replacing your HVAC system isn’t just about swapping one unit for another.
Your heating and cooling equipment is part of a larger network inside your home — and each part can affect the overall installation cost.
Let’s go over the key components that influence the final price and explain what sometimes needs to be replaced — and why.
🧊 1. Existing Line Set (Refrigerant Pipes)
The line set is the pair of copper refrigerant lines that connect the outdoor condenser to the indoor unit.
In many cases, these can be reused — they’re flushed, cleaned, and reconnected to the new system.
However, reuse is possible only when the pipe diameters match the new system’s requirements.
If the existing line set diameter is too small or too large, you may run into issues such as:
- Reduced system efficiency and capacity
- Higher compressor pressure and premature wear
- Warranty limitations from the manufacturer
💡 When line sizes don’t match, the safest and most reliable solution is to replace the line set entirely.
📦 2. Filter Housing (Filter Rack or Box)
If your old filter housing doesn’t fit the new air handler or furnace dimensions, it may need to be replaced or re-built.
A properly sized and sealed filter box improves airflow and protects the blower and coil from dust buildup.
🌬️ 3. Supply and Return Plenums
The plenums are the large sheet-metal boxes that connect your air handler to the ductwork —
one for the return air (suction side) and one for the supply air (discharge side).
Over time, plenums can collect dust, mold, or moisture damage, especially on older systems.
Even if they seem structurally sound, replacing them is often a smart move when installing a new system — it ensures clean, balanced airflow and protects indoor air quality.
✅ Our technicians at Bree HVAC strongly recommend replacing old plenums whenever possible during system changeouts.
⚙️ 4. Ductwork Condition
If your ducts are leaky, undersized, or full of debris, your new system can’t perform efficiently —
no matter how advanced it is.
Before installation, your ducts should be inspected for:
- Air leaks at joints or connections
- Sagging or disconnected runs (especially flex duct)
- Visible dust or mold buildup
Minor leaks can often be sealed; heavily damaged ducts may need replacement.
🔌 5. Electrical Components and Disconnect Box
Every HVAC system needs a dedicated electrical disconnect, proper breaker size, and correct wiring gauge.
Older homes sometimes require an upgrade to the electrical whip or breaker to meet modern safety codes.
This is a small but important detail — it ensures safety and compliance with local building standards.
💧 6. Drain Lines and Float Switches
Your indoor unit’s condensate drain system carries away moisture from the cooling coil.
When replacing equipment, technicians often install:
- A new PVC drain line,
- A secondary safety switch (to shut down the system if the drain clogs).
This inexpensive upgrade prevents potential ceiling leaks and water damage.
🧠 Final Thoughts about AC Replacement
Replacing your HVAC system isn’t just “changing the box.”
It’s a full-system AC Replacement upgrade that ties into your home’s electrical, duct, and refrigerant infrastructure.
While some parts — like the line set or ducts — can sometimes be reused, others may need updating to ensure your new system runs safely and efficiently.
📋 During Bree HVAC’s on-site inspection, we evaluate all connected components — line set, filter housing, plenums, drain, and electrical — to give you a clear, transparent estimate with no surprises later. Schedule NOW
