3 Factors That Can Affect Your Furnace Replacement Costs

When it comes to HVAC replacements, "like for like" is often the cheapest option. Replacing your old equipment with similar new equipment typically means your installation costs will be much lower. Of course, if you're replacing an old furnace, you probably don't want to install another ancient, inefficient model. You're likely replacing your old heater with a newer, more efficient model.

Unfortunately, furnace technology is always changing, so installing a new furnace may require modifications to other parts of your home's HVAC system. If you're replacing an ancient heating system with something more modern, here are three factors that may impact the installation costs for your new furnace.

1. Flue Replacement

Flue replacement is often one of the biggest factors when moving from an older standard-efficiency furnace to a newer high-efficiency model. Older furnaces are non-condensing, leaving enough heat in the exhaust stream so flue gases will naturally rise and escape. Newer furnaces extract far more energy, cooling these gases enough that highly acidic condensate will form.

This acidic condensate would quickly eat away and destroy traditional metal flue pipes. If your home uses an older furnace, its metal flue is unlikely to be suitable for a modern condensing furnace. In addition to replacing the metal flue with PVC pipe, your installer will likely need to run the new flue pipe horizontally instead of vertically.

2. Furnace Size

Many older homes may include relatively oversized furnaces, either due to outdated installation practices in the past or simply the need to install a larger furnace to account for inefficiencies. When it comes to replacing your old furnace, size does matter. Moving a large, heavy furnace will often require more effort, potentially adding a small amount to your overall replacement costs.

Additionally, installing a smaller, more modern furnace may require modifications to your existing HVAC equipment. For instance, your installers may need to extend your gas lines, modify your ductwork plenum, or run new electrical wiring. While these steps won't necessarily make a drastic price difference, they can lead to slightly higher installation costs.

3. Airflow Requirements

All furnaces have certain airflow requirements. These requirements ensure the furnace can operate efficiently and deliver heat throughout your home, all without overheating or damaging the heat exchanger. If you have an older system, your existing HVAC blower or ductwork may not provide adequate airflow for your new furnace.

Furnaces typically come with blowers, so compatibility with your air handler unit shouldn't be an issue. However, it may be important to ensure your new blower is compatible with the HVAC equipment you aren't replacing, such as your current air conditioner. Old, undersized ductwork can also be an issue, and you'll need to work with your installer to determine a cost-effective solution to these problems.

For more information about furnace replacement, contact a local company.