Replacing Central AC with Floor-Standing Units: What to Know Before Making the Switch
If your home’s central AC system is getting expensive to maintain—or you’re simply exploring alternatives—floor-standing or portable air conditioners might seem like an appealing option. They’re widely available, simple to install, and can cool individual rooms on demand. But before moving forward, there are a few important considerations to evaluate, especially when comparing the long-term practicality of a central system versus multiple individual units.
1. Understand Your Cooling Load Room by Room
Central AC systems are designed to handle the cooling load of your entire home in a coordinated way. When you switch to floor-standing units, you’re now sizing and managing the cooling requirements on a room-by-room basis.
Example:
Assume you’re cooling three bedrooms, each about 150 square feet, and a 600 square foot main living space
Cooling load is generally estimated at 20 BTUs per square foot for average insulation and ceiling height:
- 150 sq ft × 20 BTU = 3,000 BTUs needed per room
- 600 sq ft X 20 BTU = 12,000 BTUs needed for main living space
Most floor-standing AC units come in 5,000–14,000 BTU sizes, which is more than sufficient for most bedrooms or home offices, with extra capacity for sun exposure or higher ceilings.
2. Electrical Load and Circuit Capacity
One key consideration with multiple units is their combined electrical draw. A single portable AC unit might use 5 to 12 amps, depending on size and efficiency. This isn’t a problem in isolation—but running several at once can overload shared household circuits, especially in older homes.
Things to check:
- Are the outlets on dedicated or shared circuits?
- Do the rooms have 15A or 20A breakers?
- Will extension cords or adapters be required (not recommended for continuous use)?
If you plan to run multiple units simultaneously, it’s worth having an electrician confirm your panel and branch circuits can handle the added load.
3. Ventilation and Installation Needs
Most floor-standing AC units require a window for venting hot air. They come with window kits, but these can slightly reduce insulation and sealing around the window. Placement also matters—units shouldn’t be tightly boxed into a corner or blocked by furniture. Another consideration if you are making a permanent switch, would be to install dedicated exhaust ports in the wall where the AC will sit. This removes the insulation losss through a poorly sealed window exhaust.
Expect:
- A window nearby for exhaust hose connection
- Some setup time during installation
- Possible minor drafts where the hose exits the window
In homes where window space is limited or where aesthetics matter, this might be a drawback to consider.
4. Maintenance Increases with More Units
With central AC, you have one system to maintain—typically just an outdoor condenser and indoor air handler. With multiple floor-standing units, that maintenance multiplies.
You’ll now need to:
- Clean or replace filters in each unit
- Wipe down intake/exhaust vents
- Monitor individual unit performance over time
None of this is particularly difficult, but it’s a shift in how maintenance is handled day to day.
5. Efficiency and Operating Costs
While the upfront cost of portable ACs is appealing—typically around $300 per unit—they tend to be less efficient over time than a well-matched central AC system. Most portable units have SEER equivalent ratings of around 3. This pales in comparison of a central AC with a SEER rating of 16+.
Also consider:
- Noise: Floor-standing units place the compressor inside the room, and noise can range from light hums to noticeable rumbles.
- Run time: Units may run longer to compensate for heat infiltration around the exhaust hose.
6. Cost Comparison Over Time
Here’s a rough breakdown of costs for cooling a 3-bedroom section of a home with a main living space:
| Item | Floor AC Units | Central AC System |
|---|---|---|
| Upfront Cost | 4 × $300 = $1200 | $6,000 – $7,000 |
| Installation | Minimal (DIY) | Professional |
| Lifespan | 3–8 years per unit | 12–15+ years |
| Efficiency | Low SEER rating 3+ | Higher (SEER 14–20) |
| Maintenance | More frequent, multiple units | Less frequent, one system |
While the floor-standing units win in upfront cost and simplicity, they have shorter lifespans and much higher cumulative energy use, especially if multiple rooms need cooling for long periods each day. With that said, the initial cost and DIY aspect of installation and maintenance add up to a definite win for a capable homeowner.
Final Thoughts
Switching from a central AC system to individual floor-standing units is possible and, in some cases, practical—especially if you’re only looking to cool specific parts of the home. But it’s important to look beyond the upfront price and factor in electrical demands, efficiency, maintenance workload, and perceived home value.
If you’re considering this switch as a stopgap or a long-term solution, it’s a good idea to assess your electrical panel, estimate room-by-room cooling needs, and compare overall operating costs to make the most informed decision.
Premier Mechanical – www.claimyourcomfort.com – 720.207.6812