There are three major issues when a contractor installs a new HVACR system in your home. The major issues are design, installation and commissioning. A failure to do any of these tasks correctly will have an adverse effect on one or more aspect of the overall performance of your system.
Design work consists of:
1) Selecting the type of system and equipment (plus operating and safety controls) that are compatible with the architecture of your home (you may need zoning in your home), fuel availability, fuel costs, the space available for equipment and duct runs, appearance issues and project cost. You should also compare the marginal cost of an increased increment of efficiency with the potential savings and the return on this investment. At some point, the payback on more efficiency becomes unattractive.
2) Having a Manual J load calculation completed for each room and for the load on each (if more than one) central unit.
3) Use of Manual S procedures and manufacturer’s application data to select equipment.
4) Use of Manual T procedures and manufacturer’s data to locate, select and size the supply outlets and the returns.
5) Use of manufacturer’s blower data, Manual J loads and Manual D procedures to design the duct system.
When Consulting an HVACR Contractor:
- Ask the contractor for references. Find out if other customers were satisfied.
- Ask the contractor about his or her license. If a license is required in your area, ask for the license number.
- Ask the contractor if he or she is a member of the Air Conditioning Contractors of America. ACCA members have access to the latest technical information regarding HVAC systems. Through ACCA, contractors learn how to make quality an integral part of their company operations.
HVACR installation work consists of:
1) Installing the indoor and outdoor equipment, (a split system is preferred because it offers more installation options and because small tubes penetrate the building envelope).
2) Installing the refrigerant lines.
3) Installing supply air outlets and returns.
4) Installing duct runs (must be sealed and insulated to R-6 or R-8 if in unconditioned space).
5) Installing control system.
6) Installing furnace gas piping and vent (if applicable).
1) Charging the refrigerant system.
The commissioning work consists of:
1) Checking all control cycles.
2) Checking refrigerant charge.
3) Checking all power supplies, connections, fuel trains and vents.
4) Measuring and adjusting air flow at the unit and at the rooms (balancing work).
5) Educating the homeowner about the system and equipment (provide all instructions and manufacturer’s documents).
The best way to get an overview of these issues is to contact the Air Conditioning Contractors of America (ACCA) and purchase Manual RS. It’s available in their online store: Click Here
This manual explains the issues in ways a consumer should be able to understand. There also may be local codes and utility regulations that must be observed. Make certain contractors you hire have all of the appropriate licenses for installing HVACR equipment in your state and local area.
Be aware that some contractors, as a matter of policy, do the things listed above and some do not do these things. It takes more time and effort to do the job correctly. Ask them if they do these things. Expect to pay more for comprehensive service.
With regard to placement of the unit, one must consider operating cost as well as installation cost. The hot environment near the roof makes the cooling unit less efficient. However, if the ducts are in the attic, it may be less expensive to install the system with a roof location. The bottom line is that you need to find a contractor who follows the procedures that are recommended by the ACCA manuals, the manufacturer’s installation instructions, the local and state codes and the local utility regulations. (The ACCA procedures are required by code or regulation in many locations. Many utilities endorse ACCA procedures.)
Choosing a Contractor
How to Find a Quality HVACR Contractor
Most people take for granted the comfort provided by their central air conditioner, heat pump or furnace until something goes wrong and the unit needs to be serviced or replaced. When this happens, you need a quality heating, ventilating and air conditioning/refrigeration (HVACR) contractor who is knowledgeable, skilled and qualified to do the job.
A Quality Contractor:
- Complies with state and local codes and regulations and carries the proper business and Worker’s Compensation Insurance;
- Is prompt, courteous and provides fast, reliable service while attempting to perform service at your convenience;
- Has the skill and knowledge to not only service your equipment, but if necessary, to design and install the right system for you.
- Is up to date on the newest developments in equipment, technology and design procedures in order to choose and install a system which will be the most efficient and most reliable system for you.
A heating, ventilating and air conditioning system is designed to suit your needs. Your contractor selects each part of the system individually so that everything works at top efficiency to provide the comfort you need. All the system components are matched — the furnace, the condensing unit, fans and blowers, air conditioning coil, the duct work — to produce a heating and cooling system that will work best for you.
A quality contractor listens to your problems and cares about your comfort while attempting to find out if any rooms are too drafty or dry during the winter, or too hot or damp in the summer.
A quality contractor can help determine if your home or building is prone to indoor air pollution problems due to organic resins or vapors, poor air turnover or high humidity. If allergies are a problem, a quality contractor can service your heating and air conditioning system and recommend system accessories that may prevent conditions that adversely affect health and comfort.
A quality contractor is concerned about protecting the environment. Chlorofluorocarbons (CFC’s) and hydrochlorofluorocarbons (HCFC’s) used as air conditioning and heat pump refrigerant, have been linked to the destruction of the earth’s ozone layer. A quality contractor won’t release the refrigerant into the atmosphere and is trained and certified in the proper techniques for recovering, recycling, reclaiming and disposing of used refrigerant.
A quality contractor will show you how to care for your system on a day to day basis; for example, how to change the filter and how to operate the thermostat. He or she will advise you about symptoms which could signal that there might be a problem with the equipment. After servicing your equipment, he or she will let you know when it should be serviced again.
If a new system is necessary, a quality contractor will perform a Manual J load calculation, explain any changes which might be necessary in your duct system, and present options to help you make the best decision regarding replacing your old system.
A quality contractor offers planned preventative maintenance service to maximize the life of your equipment and honors the terms of the warranty on the equipment throughout the warranty period.
A quality contractor does not offer price as the only consideration. While it is a major factor, there often are valid reasons for price differences.
A quality contractor will follow up with you to make certain that you are satisfied with the service and with your new system.