When considering a new home, carefully evaluate the existing heating and cooling systems and conduct a thorough assessment that goes beyond basic home inspections. Start by finding out the age of the equipment. Statistically speaking, systems more than 15 years old are nearing their end-of-life, which means replacement planning should be an important part of your home investment strategy.

You should also assess efficiency ratings. For natural gas furnaces, look for the annual fuel utilization efficiency (AFUE). A rating of 80% is standard with higher percentages representing better efficiency. For air conditioners, the seasonal energy efficiency ratio (SEER) rating will tell you how efficient the unit is. The higher the number, the more efficient it runs.

Homebuyers checklist

• Request age and model numbers of heating/cooling equipment
• Check AFUE rating (look for 90%+ for gas furnaces)
• Check SEER rating (look for 16+ for AC units)
• Review maintenance records
• Budget for replacement if system is 15+ years old

When you move into a pre-owned home, the first 30 days are critical for understanding and protecting your heating and cooling system. Follow this simple checklist to avoid expensive surprises and keep your home comfortable year-round.

Week 1: The basics

Start simple. Change the air filter within your first week. This one task can tell you a lot about how the previous owners maintained the system. If you pull out a filter caked in dust, that’s a red flag that maintenance may have been neglected. You should also locate all components including thermostat, outdoor and indoor units and the main shutoff switch.

Month 1: Professional assessment

Within your first 30 days, schedule a performance check with a professional. A technician can help verify the following:

• Combustion systems vent properly
• Electrical connections are secure
• Refrigerant levels are correct
• Systems appear to have been maintained

Get a load calculation

While the technician is there, request a load calculation. This calculation can answer a critical question: Is your HVAC system the right size for your home?

Many older homes have mismatched systems for several reasons:

• Previous owners added insulation (reducing heating/cooling needs) but kept an old, oversized system
• Someone estimated the size instead of calculating it properly
• The home was expanded but the HVAC wasn’t upgraded

Oversized systems cycle on and off rapidly, never running long enough to dehumidify properly which can result in higher energy use, uncomfortable humidity and premature wear. Undersized systems run constantly, struggle to reach target temperatures and burn out faster.

A remodeling project is the perfect time to make system-wide upgrades. When walls are open, you have access to systems that normally cost thousands just to reach. This is the most cost-effective time to upgrade your heating and cooling infrastructure.

What you can do during a remodel:

• Seal and upgrade ductwork: Old ductwork can leak conditioned air and waste energy.
• Add or upgrade insulation: Effective insulation helps your system work more efficiently.
• Right-size your HVAC equipment: After renovating, you may need a larger or smaller unit.
• Add whole-house ventilation: Heat recovery ventilators (HRV) or energy recovery ventilators (ERV) can help maintain comfort while minimizing energy loss.

How insulation and HVAC work together

Your home’s thermal envelope — walls, roof, windows, foundation — is the barrier between conditioned indoor air and the outdoors. Every renovation change affects this envelope:

• Adding insulation means your furnace needs less capacity
• Installing energy efficient windows makes your AC work less
• Creating an open floor plan changes air flow patterns

Working with contractors who understand these interactions prevents costly mistakes like installing oversized equipment or creating moisture problems. Treat your renovation as a systems upgrade, not just a cosmetic refresh.

When planned strategically, HVAC improvements done during construction:

• May cost less than standalone projects
• Help lower energy usage over the long term
• Improve comfort and air quality immediately

Strategic planning whether you’re buying a new home or renovating an old one can help deliver long-term comfort, efficiency and environmental benefits that extend well beyond your initial investment.