How to Hire an HVAC Company for a New System: A Checklist for Success
Installing a new HVAC system is a significant investment in your home’s comfort and energy efficiency. However, the success of your investment heavily depends on hiring the right company to do the job. Too many companies cut corners, leading to inefficient systems, higher energy bills, and frequent repairs. To help you navigate this process, here's a comprehensive checklist to guide your search and ensure you hire a company that will do the job right.
1. Start with Manual J, S, and D Calculations
The foundation of a well-designed HVAC system lies in the correct calculations. Manual J is used for load calculations, determining how much heating and cooling your home needs. Manual S involves selecting the appropriate equipment size based on these calculations, and Manual D covers ductwork design. Any company that skips these steps or relies on shortcuts like rule-of-thumb methods, square footage estimates, or simply matching the size of your old equipment should be crossed off your list immediately. Proper sizing is crucial for efficiency, comfort, and system longevity.
Questions to Ask:
How do you determine the equipment size for my home?
Do you use Manual J, S, and D calculations for your designs?
2. Evaluate Their Ductwork Approach
Ductwork is a critical component of your HVAC system, responsible for delivering conditioned air throughout your home. Poorly designed or installed ductwork can lead to uneven temperatures, high energy bills, and poor indoor air quality. Beware of companies that suggest using a plenum box with multiple flex ducts attached or those who use fiberglass duct board. Also, watch out if they plan to use the same size duct for every room, regardless of its size or airflow requirements.
Proper ductwork should be made of sheet metal as often as possible. A well-designed supply trunk will reduce in size as it extends, ensuring equal airflow pressure to all rooms. While flexible ducting can be used, its application should be minimal, and there should be at least 24 inches between each supply takeoff on the trunk line. The R-value of the ductwork should be considered based on the ducts location. Hot or cold attic? Increase the R-value of the ducts in these locations.
Questions to Ask:
How do you design and size the ductwork for my home?
What materials will you use for the ductwork?
How do you ensure equal airflow to all rooms?
What R-value do you use for ductwork? Does it vary based on duct location?
3. Insist on a Detailed Commissioning Report
A thorough commissioning report is the hallmark of a professional HVAC installation. This report should include detailed data on the system’s startup, such as evacuation levels, refrigerant pressures, indoor and outdoor temperature and humidity, superheat, subcooling, total external static pressure measurements, and the amp draw on motors and the compressor. These details confirm that the system is operating within the manufacturer’s specifications and performing optimally.
However, when these measurements are off, it can lead to significant problems:
Evacuation Levels: If evacuation levels aren’t properly achieved, moisture and air can remain in the system. This can lead to corrosion, reduce the efficiency of your system, and potentially cause major damage over time. Moisture inside the system can also lead to the formation of ice, which could block refrigerant flow and strain the compressor, leading to premature failure.
Refrigerant Pressures: Incorrect refrigerant pressures can wreak havoc on your system’s performance. If the pressure is too low, the system may not cool or heat effectively, leading to discomfort and higher energy bills. On the other hand, too much pressure can strain the system, increasing the likelihood of leaks and even causing the compressor to fail prematurely.
Superheat and Subcooling: Improper superheat or subcooling readings can indicate that the refrigerant charge is incorrect. This can cause the system to work harder than necessary, leading to higher energy consumption and increased wear and tear on critical components. In some cases, it can even result in the refrigerant returning to the compressor in liquid form, which can cause significant damage.
Total External Static Pressure (TESP): If the TESP is too high, it indicates excessive resistance in the ductwork. This can lead to reduced airflow, making the system less efficient and causing it to run longer to achieve the desired temperature. Over time, this strain can lead to motor failures, increased energy consumption, and discomfort due to uneven heating or cooling in your home.
Amp Draw on Motors and Compressors: An incorrect amp draw suggests that the motors or compressors are not operating within their designed specifications. If the draw is too high, it can lead to overheating and eventual burnout, shortening the lifespan of these critical components. If the draw is too low, it may indicate that the system is not performing as efficiently as it should, potentially leading to inadequate cooling or heating.
Questions to Ask:
Will you provide a detailed commissioning report after installation?
What specific details will be included in this report?
4. Be Wary of Untrained Sales Techs
Many HVAC companies employ sales technicians who may not have the technical expertise needed to design or install a system properly. Their goal is often to sell the most expensive system rather than the right one for your home. These companies may try to win you over with flashy marketing or aggressive sales tactics, but without the necessary technical know-how, their installations could lead to long-term issues.
Questions to Ask:
Who will be designing and installing my system?
What are their qualifications and experience?
Final Thoughts: The Search for Quality is Worth It
Finding a trustworthy HVAC company may take time, but it’s a crucial step to ensuring your system is installed correctly and performs efficiently for years to come. By following this checklist, you can weed out the bad installers and find a company that will deliver the quality and reliability you deserve.
Remember, the cheapest option is not always the best when it comes to HVAC installation. Prioritize quality, ask the right questions, and don’t be afraid to walk away from companies that don’t meet these standards. Your comfort, energy efficiency, and peace of mind depend on it.
