Table of Contents
HVAC Mechanical Code Overview - Many people unfamiliar with air conditioning and heating do not know that the mechanical code regulates air conditioning and heating system installation in many municipalities.
HVAC Mechanical Code Overview | Heating and Cooling Codes
These municipalities usually have an inspection department that sends inspectors out to inspect new HVAC air conditioning and heating system installations. A few municipalities apply their own mechanical code while many others use the International Mechanical Code or another code resource, which is applicable to air conditioning and heating installations. Some use a combination of inspections, and it is wise to find out before installing air conditioning and heating equipment to find out what your local municipality uses for inspections before installing any mechanical air conditioning and heating equipment.
Authorities Having Jurisdiction (AHJ) | HVAC Mechanical Code Overview
Also, be aware that different jurisdictions (State and local) require someone licensed to install some equipment that requires advanced skills, knowledge, and experience to install correctly. Permits are required, and only a licensed HVAC or Electrical Master can apply for the permits in some jurisdictions. Deciding to install mechanical air conditioning and heating equipment without obtaining permits to complete the job, you can be fined, and the residence or building condemned if the equipment is found to be a hazard to the safety of occupants.
Many jurisdictions base their laws on codebooks like the International Mechanical Code, Various Residential and Commercial Code Books, Fuel-Gas Code, and the National Electrical Code. These books are written and evaluated by recognized professionals with many years of experience in their related disciplines. There are also liability issues involved in not obtaining permits and inspections for some mechanical HVAC installations. It is always best to do the job safely and by the book so get the proper permits and have the job inspected.
The following is a general overview of the mechanical code and what it covers for the safe and proper installation of HVAC air conditioning and heating equipment.
International Mechanical Codes References | HVAC Mechanical Code Overview
The Mechanical Code makes references to ANSI (American National Standards Institute), API (American Petroleum Institute), ARI (Air-Conditioning and Refrigeration Institute), ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers), ASME (American Society of Mechanical Engineers), ASTM (American Society for Testing and Materials), AWS (American Welding Society), Codes from various recognized code references and agencies, CSA (Canadian Standards Association), FS or Federal Specifications Standards, IIAR (International Institution of Ammonia Refrigeration), MSS (Manufacturers Standardization Society of the Valve and Fittings Industry), NAIMA (North American Insulation Manufacturers Association), NFPA (National Fire Protection Association), SMACNA (Sheet metal and Air Conditioning Contractors National Association), STI (Steel Tank Institute), and UL or Underwriters Laboratories.
Mechanical Code Administration | HVAC Mechanical Code Overview
The prelude chapter of the Mechanical Code covers the applicability of the code and administration. It covers the general powers of the mechanical inspectors and their duties to protect the safety of the public. Other parts of this prelude cover permits, inspections, violations, and offers a means of appeal. Definitions and terminology are also covered.
Basic Installation of Mechanical Equipment | HVAC Mechanical Code Overview
The second part of the Mechanical Code covers general regulations which pertain to the location of installation of mechanical air conditioning and heating equipment, a piping support table, access, and future servicing considerations, condensation piping drains and materials, drain types, minimum clearances around mechanical equipment, and secondary drains for condensation.
Ventilation Code Overview - Ventilation
The next part of the Mechanical Code deals with ventilation from natural ventilation for mechanical ventilation. There are tables and charts offering clearances and louver and grill information for a minimum amount of required ventilation. This only includes ventilation for fresh air and does not cover minimum requirements for combustion air which is covered later in another part of the mechanical code.
Exhaust Systems
The next part of the Mechanical Code covers exhaust systems including dryer vents, kitchen exhaust systems, paint rooms, movie projection room exhaust, dry-cleaning appliances, LP gas facilities, public garages, and structures housing hazardous materials. Commercial kitchen exhaust is covered along with commercial kitchen make-up air requirements. Tables include minimum duct sizes and thickness of sheet metal for exhaust ducts. Single wall metal chimneys are also covered at the end of this section.
Duct Systems
This section of the Mechanical Code covers duct systems including plenums and wiring requirements in plenums and ducts when the wire is run through these areas. Duct construction and installation and insulation ductwork are covered in this chapter. Air filters and filtration systems, smoke detectors installed in ducts, and fire and smoke dampers installed in duct systems are covered.
Combustion Air
This section of the Mechanical Code is for the installation of appliances that consume air for combustion this chapter offers minimum code requirements for the necessary amount of air for the process of combustion. It covers forced combustion air and combustion air ducts along with duct opening obstructions and location and protection.
Chimneys and Vents
This part of the Mechanical Code offers information about requirements for chimneys and ventilation for specific appliance types and vent types. Do and don’ts for using chimneys for ventilation of combustion by-products and termination of vents and chimneys above the roof. Tables include a minimum size of vents for BTU/h of appliances and minimum distances of vents to combustible materials.
Special Appliances, Fireplaces, and Solid Fuel Burning Appliances
This section of the Mechanical Code covers fireplaces, fireplace stoves, and heaters, special appliances which produce heat or are used for cooking, gas logs, incinerators and crematories, wall furnaces, floor furnaces, direct fired air heating equipment, infrared radiant heaters, clothes dryers, illuminating appliances, sauna heaters, engine and gas turbine-powered equipment and appliances, pool and spa heaters, cooking appliances, forced warm air furnaces, unit heaters, unvented room heaters including unvented gas logs, vented room heaters, kerosene, and oil-fired stoves, small ceramic kilns, and finally cooling towers, evaporative condensers, and fluid coolers.
Boiler Code Overview - Boilers, Water Heaters, and Pressure Vessels
This section of the Mechanical Code covers the installation, alteration, and repair of boilers, water heaters, and pressure vessels. It covers boiler connections, safety, and pressure relief valves and controls, boiler low water cutoffs, steam blow-off valves, hot water boiler expansion tanks, gauges on hot water and steam boilers, and testing of boilers and pressure vessels. It is important to note that this section is also applicable to LP Containers, bulk oxygen storage tanks, and medical gases.
Refrigeration Code Overview - Refrigeration
This section of the Mechanical Code covers refrigeration including the purity of refrigerants, recovered refrigerants, reclaimed refrigerants, and refrigeration classification. Includes information on storage, ventilation requirements for storage areas and refrigeration equipment rooms, refrigeration alarms and detectors for the safety of occupants, refrigerant piping, and field testing of refrigerant piping systems.
Hydronic Piping
This section of the Mechanical Code covers pipe materials, joints, and connections, piping insulation, valves, transfer fluid, testing of hydronic pipe, and embedded piping.
Fuel Gas Piping | HVAC Mechanical Code Overview
This section of the Mechanical Code covers gas pipe, materials, installation, and sizing for LP and natural gas. This section has equations for sizing pipe and BTU requirements for equipment including length of run of pipe, the pressure of the gas, and specific gravity. Tables are also included for pipe sizing, length of run, and specific gravity and pressure. Included in this section are requirements and code for gas shut-off valves, two-psi and higher gas piping, gas flow controls including regulators, appliance connections, CNG gas-dispensing systems, and supplemental and standby gas supplies.
Fuel Oil Piping and Storage – HVAC Mechanical Code Overview
This section of the Mechanical Code covers materials used for fuel oil storage tanks and fuel oil piping, fuel oil pipe joints and connections, fuel pipe support, fuel oil system installation, oil gauges, fuel oil shutoff valves, and testing of fuel oil piping.
Solar Systems – HVAC Mechanical Code Overview
This section of the Mechanical Code covers the installation and materials used for solar systems. Also covers heat transfer fluids, collectors, and thermal storage units.
HVAC Mechanical Code Overview
Technical Resource: Refrigeration and Air Conditioning Technology
My Son and his Family are renting a Town Home and they have an Air-conditioned Wall Mounted Unit which is exhausting its hot air into an enclosed Patio which get super hot melting anything you try to store in the Patio. This heat is so great that it is coming back into the home. The Owner does not want to do anything about this condition and just told him not to store anything in the Patio. Is this a Legal installation and if not, where can i get the code to properly install a Wall Air-Conditioner which will sate proper exhausting? Any help will be greatly appreciated.
Definitely not good for the condenser/compressor and likely violates the manufacturer’s warranty. If it was inspected it should have failed. Not sure you can do anything about it now except to make sure the space is well ventilated with outside air.
“The code” is just a way to rip off customers. The customer/victim needs to confirm with their city, county, or state whether the “voluntary” codes are required.
This is especially true when dealing with home warranty companies. The “code dance” is solely so the HVAC company can squeeze more money out of the home owner than what the warranty company will pay them.
Most of the time the HVAC company can not cite the code book nor do they have a copy of it.
The authors of the code book periodically change codes so the HVAC companies can rip off their clients (especially elderly homeowners) by claiming the homeowners will be charged criminally for not “bringing the house/appliance up to code.
You are entitled to your opinion but I disagree. I have seen many people who will purchase their own unit online and are either totally ignorant of safety issues or ignore them and do some seriously dumb and dangerous things when installing it themselves. Also hacks that do quick change outs and never pull a permit and NEVER have any quality to their work don’t really care about safety, its about safety. It’s kind of like the rules of driving. Those who don’t follow the rules are reckless and a danger to everyone else.
If following codes is a legal requirement that is one thing. But in a non code area when the tradesman tells the elderly they are required to “bring it up to code” that is pure fraud and that is why people don’t trust tradesmen.
A thief is a thief
Wrong again!! If a tradesman works on something and it is not up to code and then something happens as result of that such as the house burning down or someone dying because of CO poisoning the tradesman will lose their license and GO TO JAIL!!! The codes are not there for everyone’s whim to just ignore. Many who sit on the code councils are very experienced tradesman and engineers that have observed disasters as a result of unsafe workmanship or a lack of knowledge.
I have three licenses (Master Electrician, Master HVAC, & Master Gas Fitter) but rarely work in the field now but when I do its always up to code and permits are pulled. Usually I exceed the code in some instances to be safe. I typically end up losing a bid to some jack leg who doesn’t work up to code therefore doesn’t pull permits therefore does dangerous work. But the homeowner/businessperson saved a few bucks at the expense of safety and doing it right……………effing dumb when someone gets hurt or dies because they saved 50 bucks using single wall vent instead of b-vent. Or not lining the chimney and chimney collapses? I could go on and on with this stuff because I’ve seen it firsthand. Most of those jack legs cannot be found after the installation as they are off somewhere to create another disaster. So who would you rather call to do your work? Someone who follows the code and shows excellent workmanship in their work or someone just trying to make a quick buck and will never be seen again?
The elderly person you speak of, is their life not worth the cost of doing it up to code?
So you won’t be branded as a lying conman please cite a case where a tradesman anywhere in the USA at any point in history a tradesman was prosecuted or fined for not bringing a house up to code in a non code area
Codes are privately published “suggestions ” without force of law unless a government authority adopted the codes.
Scammers and con men lie.
Call me whatever the F#*K you want to call me. I’ve got nothing to prove to you! My customers know me and know when they call me to fix something it will be done right. I’m not gonna speak for the whole trade because there are thieves and liars in every practice and trade. There is also incompetence in every practice on Earth. If you blanket everyone in that way you are disgusting and a douche bag (which I am thinking you are anyway). The guys that do it right by the code are doing it because they take pride in their work and do it by the book for safety/quality reasons. You hire some nut off the street who doesn’t have a clue what they are doing and you are asking for trouble. And I don’t have access to a Lexus/Nexus database but I have seen it and experienced it myself. In my current line of work, I find crap all the time where a contractor tried to cut corners or hired someone who really didn’t know what they were doing. Those are usually unlicensed off the street guys just trying to make a quick buck and then moving on to something else. Those are your con men right there.
Someone with a license has their name and business registered with the state have no problem doing it right and if they don’t they are held accountable by the state. Its why they issue licenses to hold them accountable. Its why they have to study and take tests and prove they know what they are doing and understand safety. Obviously you are butt hurt by something and have an ax to grind. This is not your safe space.
When you need a doctor do you go to a hospital or do you find a witch doctor to cure your ailment? Same thing here.
BTW, this conversation is over. Find another place to grind that ax!
So let me in on a secret most HVAC clowns are scam artist. I had one over last year to fix an issue I was having with the heating furnace. Turns out he cut off the AC line while under the fan and when Spring came around guess had to call him back because the AC would not kick on. Turns out he tried to charge me 180$ to turn it back on. I ask him what the problem was he side someone unplugged the AC wire. I told him he was the last person under there. Then he gave me 90$ back for realizing he was the fault of the problem. Good luck trying to save your industry on this one.
So let me in on an HVAC customer clown who wants to paint an entire industry with one broad stroke of a brush because of single issue this clown had with someone who may or may not have been a licensed HVAC technician. Good luck living in clown world.
can a master plumber install duct, registers and grills in a country house
Anyone can install anything…………….the real question is…..can they do it correctly?