{"id":108754,"date":"2026-02-09T15:16:37","date_gmt":"2026-02-09T23:16:37","guid":{"rendered":"https:\/\/www.redfin.com\/blog\/?p=108754"},"modified":"2026-02-09T15:16:37","modified_gmt":"2026-02-09T23:16:37","slug":"choosing-an-hvac-system","status":"publish","type":"post","link":"https:\/\/www.redfin.com\/blog\/choosing-an-hvac-system\/","title":{"rendered":"Choosing an HVAC System: Sizing, Costs, and Timing"},"content":{"rendered":"

Installing a new HVAC system is a big decision, whether you\u2019re upgrading your forever home or <\/span>getting your house ready to sell<\/span><\/a>. Beyond the upfront cost, the choices you make when choosing an HVAC system can affect comfort, energy bills, and long-term value. Knowing what to expect before work begins helps homeowners avoid common mistakes and make smarter decisions from the start.<\/span><\/p>\n

In this <\/span>Redfin<\/span><\/a> article, industry experts break down what homeowners should know before installing a new HVAC system and how to turn that guidance into practical next steps.<\/span><\/p>\n

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1. Proper sizing matters more than most homeowners think<\/span><\/h2>\n

One of the most common HVAC mistakes is assuming a bigger system will perform better. In reality, size directly affects comfort, efficiency, and wear on the equipment.<\/span><\/p>\n

\u201cBefore installing a new HVAC system, homeowners should make sure it\u2019s properly sized for their home,\u201d says HVAC contractor <\/span>T.F. O\u2019Brien<\/span><\/a> of <\/span>Long Island, NY<\/span><\/a>. \u201cBigger isn\u2019t better. An oversized system can cycle too often, waste energy, and reduce comfort.\u201d<\/span><\/p>\n

Josh Wayman, President of <\/span>Sanitair Air Duct Cleaning<\/span><\/a> in <\/span>Salt Lake City, UT<\/span><\/a>, adds that relying on the old unit\u2019s size often leads to problems. \u201cHomeowners should make sure the system is properly sized based on a real load calculation, not just the old unit,\u201d he explains. \u201cThe wrong size leads to short-cycling, humidity issues, uneven comfort, and higher bills.\u201d<\/span><\/p>\n

When choosing an HVAC system, a professional <\/span>contractor<\/span><\/a> should evaluate square footage, insulation, windows, ductwork, and actual household usage. This step sets the foundation for long-term performance and helps avoid issues that show up almost immediately after installation.<\/span><\/p>\n

2. Check ductwork and airflow before installing new equipment<\/span><\/h2>\n

New HVAC equipment cannot compensate for poor duct conditions. If the ductwork struggles, the system will too.<\/span><\/p>\n

\u201cIt\u2019s smart to evaluate the ductwork and airflow first,\u201d Wayman with Sanitair Air Duct Cleaning says. \u201cLeaks, poor returns, or restricted ducts can make even a brand-new system perform badly.\u201d<\/span><\/p>\n

Before installation, homeowners should consider having ducts inspected, sealed if needed, and professionally cleaned. Proper airflow supports consistent temperatures, better indoor air quality, and lower energy waste. From a real estate perspective, well-maintained ductwork also reassures buyers that the home\u2019s systems haven\u2019t been overlooked.<\/span><\/p>\n

Read>> <\/i><\/b>Home Maintenance Checklist for Every Season<\/i><\/b><\/a><\/p>\n

3. Evaluate the existing system for hidden issues<\/span><\/h2>\n

Understanding why the old system underperformed can prevent repeat problems with the new one.<\/span><\/p>\n

\u201cHomeowners should make sure their existing system has been properly evaluated, including refrigerant levels, electrical components, and coils,\u201d says Dennis Laliberte, COO at <\/span>Sarasota, FL<\/span><\/a>-based home improvement company, <\/span>Wrench Group<\/span><\/a>. \u201cUnderlying issues can impact the performance of a new unit.\u201d<\/span><\/p>\n

If electrical faults, refrigerant problems, or airflow issues remain unresolved, the new system may inherit those inefficiencies. Addressing these problems early helps homeowners make better decisions when choosing an HVAC system and prevents avoidable setbacks.<\/span><\/p>\n

4. Look beyond price when comparing efficiency and features<\/span><\/h2>\n

It\u2019s tempting to focus on upfront cost, but long-term performance depends on more than the price tag.<\/span><\/p>\n

\u201cDon\u2019t choose based on equipment price alone,\u201d Wayman advises. \u201cCompare efficiency ratings, ask about proper refrigerant charging and start-up testing, and confirm the installer will pull permits and register the warranty.\u201d<\/span><\/p>\n

Higher efficiency systems can reduce monthly energy bills and appeal to future buyers. More importantly, correct installation practices matter just as much as the equipment itself. \u201cA quality install with the right airflow and setup matters as much as the brand you pick,\u201d Wayman says, \u201cand it\u2019s what drives comfort, longevity, and real efficiency.\u201d<\/span><\/p>\n

5. Timing your HVAC installation can improve results<\/span><\/h2>\n

When you install a new system can affect how smoothly the process goes.<\/span><\/p>\n

\u201cHomeowners should plan installation during milder seasons to ensure the system and thermostat are tested before the busy summer or winter seasons,\u201d <\/span>Wrench Group<\/span><\/a>\u2019s Laliberte recommends.<\/span><\/p>\n

Spring and fall installations allow time to identify and correct issues without extreme temperatures. For sellers, this timing also reduces the risk of HVAC-related surprises during <\/span>home inspections<\/span><\/a> or showings.<\/span><\/p>\n

6. Quick HVAC installation checklist for homeowners<\/span><\/h2>\n

Before committing to an installer or system, it helps to step back and confirm the basics. Use this checklist as a quick reference while choosing an HVAC system:<\/span><\/p>\n