About Us

About Us 

Local Heating & Cooling Solutions for Homes & Businesses in the Great Lakes Bay Region

Since 1984, we’ve served homeowners and small businesses across Bay City and surrounding areas with heating and air conditioning solutions built to last. At Custom Engineering, we’re a locally owned and operated HVAC company based here in Mid-Michigan, and that local focus shapes how we do business every day.

Whether we're on a call in Saginaw, handling an installation in Midland, or walking someone through a late-night issue over the phone, our goal is always the same: to work with people in a straightforward, honest, and helpful way.

See How We’re Giving Back We're proud to support our Bay City community through local events, partnerships, and service.
  • Affordable Financing Options
    We make HVAC services affordable with financing options offering 0% interest for 72 months.
  • Available Nights & Weekends
    No matter when you need us, we're ready to help. Someone is always available to answer your call.
  • Preventative Maintenance Plans
    Keep your system in perfect shape all year round with our programs.
  • Locally Owned & Operated
    As a proud Michigan company, we deliver honest, dependable HVAC services backed by local expertise and care.

Hear From Our Happy Customers

    "So grateful to them!"
    I needed help, and Custom Engineering got to me fast and saved the day. Nick, the technician, was great. He was personable and intelligent and he got my repair done super fast. Thanks, Custom Engineering!
    - James T.
    "I don't know what I do without this company!"
    Chaz did an amazing job - straightforward and very helpful. Jason and Trey set up the furnace a week ago, and it runs amazingly! It's nice to stay warm again. They just repaired and replaced my bathroom exhaust fan, too. Thank you again!
    - Cesily W.
    "Custom Engineering took care of us right away!"
    Our initial call was after hours and not an emergency. We received a call first thing the next morning, and they came out within a few hours. Both gentlemen were very professional and knowledgeable, and were able to repair our furnace right then and there.
    - Reid K.
    "They have been an excellent company to work with."
    Always courteous & competent. They installed a new furnace, AC, garage gas heater, and ran a gas line into our laundry room. They stayed on the job until all was completed and we were extremely satisfied.
    - Terrance V.
    "10/10 Service!"
    Had Customer Engineering come out to my restaurant to diagnose my furnace and walk-in freezer. Brandon and Skylar, the techs, were amazing. Extremely friendly and knowledgeable. I will be using them for all my HVAC needs moving forward.
    - Taylor A.
    "This business is the best!"
    We bought our kitchen hood system from them, which they also installed (no small task). They are dependable, efficient, and do great work. Prices are what I would expect for the job. Don't hesitate to hire them.
    - Marinell S.
    "Nick was fantastic!"
    He got our furnace up and running again very quickly (on a Saturday!). Very personable and professional! We will definitely be using Custom Engineering Heating & Cooling again - thank you!
    - Krista W.
    "My experience with the company was great!"
    Chaz went above and beyond! He fixed my main house furnace and also advised me on my ceiling-mounted furnace in my back building. Thank you for your quick response. I will use you again!
    - Ann K.
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Who We Are

We’re a team of long-time HVAC professionals with deep roots in the Bay City area. Over the years, we’ve grown from a small outfit into a trusted resource for homes and businesses across Bay, Midland, and Saginaw counties. Even as the industry has changed, we’ve stayed focused on what matters most: showing up, listening, and offering the kind of personal service that keeps people comfortable through every season.

We’re licensed and insured and offer full-service heating and cooling, from repairs and tune-ups to complete system replacements. Whether you’re dealing with a furnace issue in February or trying to cool down your home in July, we’ll help you explore options that fit your space and budget.

Our Approach

We don’t believe in high-pressure sales tactics or one-size-fits-all answers. Every call we get is a little different, and that’s precisely how we treat it. If you're unsure whether something’s urgent, we’ll talk it through and help you figure it out, no obligation, no runaround. Sometimes we can walk you through a quick fix over the phone. If not, we’ll let you know what the next steps might look like.

We also offer free estimates on new system installations and 0% financing through Wells Fargo for those who qualify. Whether you're replacing older equipment or planning a more efficient setup, we’re happy to explain your options and answer any questions.

Proud to Offer Mitsubishi Electric Systems

We’re trained and equipped to install and service Mitsubishi Electric systems, one of the leading names in ductless and energy-efficient heating and cooling. These systems are a smart choice for Michigan homes and businesses, especially when dealing with hard-to-condition spaces or older ductwork. Being a Mitsubishi Electric Ductless Pro Elite Contractor gives us access to extended warranties and product options beyond standard dealer offerings.

Need HVAC help in Bay City or nearby? Call (989) 474-2870 for 24/7 support.

BE COMFORTABLE IN EVERY SEASON Check Out Our Preventative Maintenance Programs

With regular tune-ups, special discounts, and priority service, our programs will keep your equipment in quality shape year-round.

Learn More
Proudly Serving the Tri-City Area

Custom Engineering is proud to serve Bay City, Linwood, and other surrounding areas.

  • Akron
  • Auburn
  • Bay City
  • Beaverton
  • Bentley
  • Bridgeport
  • East Tawas
  • Essexville
  • Fairgrove
  • Frankenmuth
  • Freeland
  • Hamilton
  • Hemlock
  • Horton
  • Kawkawlin
  • Lupton
  • Merrill
  • Midland
  • Omer
  • Pinconning
  • Reese
  • Rose City
  • Saginaw
  • Sand Lake
  • Sanford
  • Shields
  • Skidway Lake
  • St. Charles
  • Standish
  • Sterling
  • Turner
  • Twining
  • Unionville
  • Whittemore
  • Zilwaukee

Serving Bay City, Saginaw, Midland & Beyond

We provide same-day service, emergency repairs, and full HVAC replacements for homes and small businesses across Bay City, Saginaw, Midland, and surrounding areas, including Auburn, Bay County, Saginaw County, and Midland County. Whether it's a quick repair or a complete system upgrade, we deliver reliable support at competitive prices.

Contact us today at (989) 474-2870 for 24/7 support from one of our team.

Financing Available Invest in your home comfort today with our financing options!

Ask the Experts

Common Answers To Your Questions

Curious about heating and cooling? Our Custom Engineering team has you covered. Browse through common questions and find expert advice straight from our pros.

  • Why should I buy Energy Star labeled equipment?
    The average home spends about $1,900 annually on energy bills. Heating and cooling accounts for as much as half of a home's energy use. The EPA provides important recommendations for energy-efficient equipment, including proper sizing, quality installation and maintenance, and other home improvement considerations to help you get the most out of the heating and cooling products you purchase, save energy, and save as much as 20% annually on your total energy costs.

    ENERGY STAR-qualified products prevent greenhouse gas emissions by meeting strict energy efficiency guidelines set by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE).
  • What is a Geothermal system?
    The Earth absorbs almost 50% of all solar energy and remains at a constant temperature of 50°F to 70°F, depending on geographical location. A geothermal unit utilizes this constant temperature for heating and cooling your home. You can save up to 60% on your power bills compared to a traditional system. There is no flame, flue, odors, or loud outdoor equipment. Heating, air conditioning, and hot water can all be attained from a single compact unit.
  • What if I smell gas?
    Propane (LP) gas: You have this type if your gas comes from a tank located outside close to your house. Propane is stored as a liquid under pressure in tanks and cylinders. In most residential applications, propane is used as a vapor. When liquid propane changes into a gas vapor, it expands in volume. This means that even a small leak of liquid propane can result in a much larger quantity of propane vapor, which can be especially dangerous in a confined space. A chemical odorant has been added to propane to give it a distinct smell. Learn to identify this odor. Propane gas is heavier than air, so it will sink to the floor and spread. To check for the presence of propane, carefully smell all over a room, especially in low spots.
    If you smell propane (LP) gas:
    • Exit your home immediately.
    • Propane gas can ignite easily. Do not light a match, start an engine, use a cell phone, or do anything that may create a spark.
    • From a safe area, contact your propane supplier and call 911.
    • If you can, shut the propane gas supply off at the tank.
    • Stay away from your home until you've been told that it is safe to return.

    Natural gas: You have this type if you have a gas meter and pay a natural gas supplier or utility. A chemical odorant has been added to natural gas to give it a distinct smell. Learn to identify this odor.
    If you smell natural gas:
    • Exit your home immediately.
    • Do not light a match, start an engine, use a cell phone, or do anything that may create a spark.
    • From a safe area, contact your gas company or call 911.
    • If you are able, turn the gas off at the meter.
    • Stay away from your home until you've been told that it is safe to return
  • How can I reduce my energy costs?
    Cooling
    • Upgrade to a high-efficiency air conditioner - Swapping your old, inefficient air conditioning system for a high-efficient one can cut electricity bills by one-third. Consult one of our professional technicians to ensure your system is the right size for your home and you aren't over or under-cooling for your space needs.
    • Turn up the temperature - To save electricity during the summer, set the temperature above 75° as every degree below this will add an extra three to five percent to your energy bill.
    • Install ceiling fans - Change the direction of airflow on your ceiling fans. In the summer, the blades should operate in a counter-clockwise direction to create a nice, gentle wind.
    • Have annual maintenance performed - Having annual maintenance performed on your air conditioner by a licensed technician will help ensure it operates at its peak efficiency. It catches any potential breakdowns before they occur.
    • Don't block vents in well-used rooms - Keep your supply and return air vents free of objects like blinds, carpets, or furniture so your air conditioner can operate efficiently and there is even cool air distribution.

    Heating
    • Upgrade to a high-efficiency furnace - New high-efficiency furnaces use up to 50% less fuel than an older system. It can save you up to 25 percent of your home-heating costs in one year, and within a few years, you'll have recovered the initial cost of replacing/upgrading your furnace. Choosing a model with an energy-efficient motor can save 20 to 50 percent of the energy needed to operate a fan motor continuously. Let us show you the advantages of replacing your old furnace today.
    • Have annual maintenance performed - Having annual maintenance performed on your furnace by a licensed technician will help ensure it operates at its peak efficiency. It catches any potential breakdowns before they occur.
    • Install a programmable thermostat - A programmable thermostat lets you control your home's temperature when you're away or asleep. For every 1° you lower your thermostat for seven hours per day, you save one percent on your heating bill.
    • Don't block vents in well-used rooms - Keep your supply and return air vents free of objects like blinds, carpets, or furniture so your furnace can operate efficiently and there is even heat distribution.
    • Install ceiling fans - Change the direction of airflow on your ceiling fans. In the winter, the blades should operate in a clockwise direction, helping to push the warm air from the ceiling down into the room.

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