The Quick Comparison

Window units cost $150-$500 each and cool one room. Central AC costs $3,500-$10,000 but cools your entire home. The right choice depends on how many rooms you need to cool, how often you use AC, and whether your home has ductwork.

Window Units: Pros and Cons

When Window Units Make Sense

If you only need to cool one or two rooms, window units are hard to beat on price. They require zero installation — just plug them in. They are ideal for renters, for cooling a single bedroom at night, or for homes where you only use AC a few weeks per year. In Denver's climate, some homeowners get through summer with just a bedroom window unit since many nights cool down into the 50s and 60s.

The Downsides

Window units are noisy, block your window view and natural light, are less energy efficient per BTU than central air, don't filter air as well, and look unattractive from outside. If you need 3-4 window units to cool multiple rooms, you're spending $600-$2,000 and using more electricity than a central system would. They also need to be installed and removed each season.

Central AC: Pros and Cons

When Central AC Makes Sense

If you want whole-home cooling, central AC is the way to go. It cools every room evenly, filters your air, runs quietly (the noisy compressor is outside), and adds value to your home. In the Denver market, central AC is expected by homebuyers — a home without it can sell for $5,000-$15,000 less. If you plan to stay in your home 5+ years, central AC almost always pays for itself in home value alone.

The Downsides

Higher upfront cost and you need existing ductwork (or need to install it). Installation takes 1-2 days. If your home doesn't have ducts — common in older Denver bungalows and some mid-century homes — adding ductwork can cost $3,000-$7,000 on top of the AC system.

The Third Option: Ductless Mini Splits

If your home lacks ductwork but you want whole-home cooling, ductless mini splits are the best of both worlds. They install without ducts (just a small hole in the wall), cool individual zones efficiently, and work as heaters in winter too. A single-zone mini split costs $3,000-$5,000 installed; a multi-zone system for a whole home runs $8,000-$15,000. They are extremely popular in older Denver neighborhoods like Capitol Hill, Park Hill, and Wash Park where homes were built before central air was standard.

Denver-specific tip: Our dry climate means evaporative coolers ("swamp coolers") are another option that many Front Range homes use. They cost $1,500-$3,500 installed and are very cheap to run. However, they struggle on humid days (monsoon season in July-August) and add moisture to your home. Many Denver homeowners use a swamp cooler most of the summer and only run AC during the muggy weeks.

Cost Comparison Over 10 Years

Three window units running all summer cost roughly $400-$600 per year in electricity. A central AC system costs $200-$400 per year for the same home. Over 10 years, the central system saves $2,000-$4,000 in electricity — partially offsetting the higher purchase price. Add in the home value increase, and central AC typically comes out ahead for homeowners who stay 5+ years.

Our Recommendation

If you own your home and plan to stay, invest in central AC or ductless mini splits. If you rent, or only need cooling for a few weeks per year, window units are a practical choice. Either way, make sure whatever you choose is properly sized for your space — an undersized unit will run constantly and an oversized unit will cycle too frequently, both wasting energy.