Festus, MO · Jefferson County

Heating Installation Built Around Your Home, Not Just the Equipment

Exactly what's wrong. Exactly what it costs. In writing.

A new heating system should do more than fit where the old one sat. ExactAir looks at the home’s heating requirements, existing system, airflow, installation conditions, and equipment options before the work begins — then installs and verifies the system to the proper standard.

Veteran-Owned · Family-Owned · EPA Certified · Fully Insured · Est. 2025

Signs It's Time to Consider a New Heating System

How do you know replacement is worth looking at?

A heating system doesn’t have to stop working completely before replacement becomes a conversation. These signs can indicate that it’s time to evaluate the system and the home together:

The furnace is approaching the end of its expected service life
Repairs are becoming more frequent or expensive
Some rooms consistently struggle to stay comfortable
The system runs for long periods without maintaining temperature
Heating performance has noticeably declined
Energy costs have increased without a major change in usage
The system has major component or safety concerns
You’re planning a remodel, addition, or major home improvement

What Happens During a Heating Installation

What we evaluate before the new system goes in

ExactAir does not treat installation as simply removing one piece of equipment and putting another in its place. The installation starts with understanding what the home and system actually require.

Exact Home Assessment

The home's size, layout, insulation, comfort concerns, and other conditions are considered to understand the heating requirements.

Exact Equipment Sizing

Equipment capacity is selected around the home's requirements instead of automatically matching the size of the existing system.

Exact System & Infrastructure Check

Existing ductwork, airflow, electrical requirements, equipment location, connections, and other supporting components are evaluated before installation begins.

Exact Equipment Selection

Available equipment options are considered based on the home's requirements, installation conditions, comfort goals, and practical system needs.

Exact Installation

The new heating equipment and required connections are installed according to manufacturer requirements and applicable installation standards.

Exact Verification

The completed system is started, tested, and checked to confirm proper operation before the installation is considered finished.

Why Jefferson County Homeowners Choose ExactAir for Heating Installation

Sizing based on the home

The goal is to install equipment that matches the home's actual heating requirements rather than simply replacing the old unit with the same size.

The whole system gets considered

The equipment is only one part of the installation. Airflow, ductwork, electrical requirements, connections, placement, and other system conditions matter too.

Installation done to standard**

ExactAir follows manufacturer requirements and a documented installation process rather than treating every replacement like the same job.

Clear explanation before the work begins

You'll understand what is being installed, why it fits the home's requirements, and what the installation involves before the work starts.

Owner-level accountability

Brett Lahue is personally responsible for the work and customer experience ExactAir provides.

Where "Exact" comes from

ExactAir Heating and Cooling was founded in 2025 by Brett Lahue — an Army veteran who learned the trade the old way, checked off job by job under his father, a by-the-book technician himself.

When a job was done right, the answer was always the same word: “Exactly.” The name, and the standard behind it, stuck.

Today ExactAir is a small, owner-operated company serving Festus and Jefferson County — background-checked, EPA certified for both Universal and A2L refrigerants, and insured through Federated Insurance.

— Brett Lahue, Owner & Lead Technician

Heating Installation in Festus & Jefferson County, MO

ExactAir is based in Festus and provides residential heating installation throughout Jefferson County and the surrounding St. Louis Metro area, generally within about 45 minutes of Festus.

Note: A trip fee applies past the standard service radius. Service inside St. Louis city and St. Louis County is currently limited, pending additional licensing there.

What Customers Say About ExactAir's Installations

    
 
 
         
   KEITH CROWDEN 
 
 
 
 Trustindex verifies that the original source of the review is Google. Exactair did a great job installing my new Air Conditioner. Best price exceptional service I highly recommend Exact Air
  
 
        
   james blehm 
 
 
 
 Trustindex verifies that the original source of the review is Google. The technician  found what others couldn't.  He was timely and professional.  Pricing was easily affordable!  I will definitely be using them again for a new split system install. And would recommend to everyone!!
  
 
        
   Carole Kronmueller 
 
 
 
 Trustindex verifies that the original source of the review is Google. Exact AIR Is a wonderful HVAC business They are very efficient , reliable , affordable, and the best part is Brett Will give you personalized attention and make it a point if you have an emergency or not , to make it out and get you up and running. I highly recommend them, and I have shared their contact with several of my family members and friends that have asked. One other  note, it is a veteran owned company🇺🇸🇺🇸🇺🇸🇺🇸
  
 
        
   Guadalupe Rios 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had a great experience with ExactAir Heating and Cooling from start to finish. Mr. Lahue  was  very knowledgeable, efficient, and made sure everything was working properly before leaving. The pricing was fair, and I appreciated the honest recommendations without any pressure to purchase unnecessary services. It's refreshing to work with a company that values quality and customer service. I would definitely recommend them to anyone looking for reliable AC repair or maintenance.  Promote Ahead of Peers.

Frequently Asked Questions

Heating Installation FAQs

How much does a new heating system installation cost?

The cost depends on the equipment, home requirements, installation conditions, and any supporting system work needed. ExactAir evaluates those factors before presenting the installation options and pricing.

How do you determine what size heating system my home needs?

Equipment sizing should be based on the home’s heating requirements rather than simply copying the capacity of the old system. ExactAir evaluates the home and relevant system conditions before selecting equipment.

Can you replace my existing furnace with a different size?

The replacement does not have to match the old equipment’s capacity. If the existing system was incorrectly sized or the home’s conditions have changed, ExactAir evaluates what capacity is appropriate for the home.

Do you replace the ductwork during a heating installation?

Not every installation requires ductwork replacement. ExactAir evaluates the existing system and determines whether the ductwork and airflow can properly support the new equipment or whether modifications should be considered.

How long does a heating installation take?

Installation time depends on the equipment and the complexity of the job. Once the existing system and installation conditions are evaluated, ExactAir can explain what the particular installation will involve.

Will you test the system after installation?

Yes. The completed system is started and checked to verify that the equipment and installation are operating as intended before the job is considered complete.

Put the right heating system in the right home — and know it was installed correctly

Monday–Friday, 7am–7pm · 24/7 emergency service available