Air Handler Installation Requirements
INSTALLATION REQUIREMENTS
The following is an excerpt from the actual product installation guide. The complete guide can be obtained free of charge from HomeAirDirect.com
These instructions are intended as a general guide only for use by qualified persons and do not supersede any national or local codes in any way. Compliance with all local, state, or national codes pertaining to this type of equipment should be determined prior to installation. Read this entire instruction manual, as well as the instructions supplied in separate equipment, before starting the installation. All models are designed for indoor installation only. The installation of the air handler, field wiring, warm air ducts, etc. must conform to the requirements of the National Electrical Code, ANSI/NFPA No. 70 (latest edition) in the United States, and any state laws, and local ordinances (including plumbing or wastewater codes). Local authorities having jurisdiction should be consulted before installation is made.
Such applicable regulations or requirements take precedence over the general instructions in this manual. Install the conditioned air plenum, ducts and air filters (not provided) in accordance with NFPA 90B Standard for the Installation of Warm Air Heating and Air-Conditioning Systems (latest edition). The air handler is provided with flanges for the connection of the plenum and ducts. Air filters (not provided) must be listed as Class 2 furnace air filters.
The air handler can be used with R-22 or R410A from the factory. The air handler is shipped from the factory completely assembled. Some models are configured for upflow air discharge only, and some models are configured for upflow or horizontal left-hand air discharge. The air handler cabinet conforms to 2 percent or less air leakage. Do not remove the cabinet knockouts until it has been determined which knockouts will need to be removed for the installation. Select the final installation position which best suits the site conditions.
Consider required clearances, space, routing requirements for refrigerant line, condensate disposal, filters, ductwork, wiring, and accessibility for service. Refer to the air handler rating plate on the air handler for specific information.
Gather the required tools and parts before starting installation. Read and follow the instructions provided with any tools listed here.
Tools Needed
- 1/4″ nut driver
- Level
- Screwdriver
- Adjustable Wrench
- Tape Measure
- Hammer
- Sealant
Parts Needed
Check local codes, check existing electrical supply, and read “Ductwork Requirements”, and “Electrical Requirements” before purchasing parts.
- UL listed wire nuts
- Replacement orifice (if needed). See “Verify Orifice Size.”
The correct orifice size may be contained in the replacement orifice package located inside the control box of the outdoor unit. If this package does not contain the correct orifice for your air handler, you must purchase the correct orifice size.
System Requirements
The air handler is designed to match, and must be used with outdoor units as rated. The indoor units are manufactured with an interchangeable refrigerant metering orifice to provide optimum refrigerant control and system performance with a variety of different capacities of outdoor units. In some cases, the rating of the outdoor unit may require that the air handler coil assembly orifice be changed to obtain rated
performance.
Location Requirements
NOTE: When used on cooling applications, excessive sweating may occur when the air handler is installed in a very humid space.
- If installed in an unconditioned space, sealant should be applied around the electrical wires, refrigerant tubing, and condensate lines where they enter the cabinet.
- Electrical wires should be sealed on the inside where they exit the conduit opening. Sealant is required to prevent air leakage into and condensate from forming inside the air handler, control box, and on electrical controls.
- The air handler must be installed in such a way as to allow free access to the coil/filter compartment and blower/control compartment.
- The air handler must be installed in a level position to ensure proper condensate drainage.
4 Responses to “Air Handler Installation Requirements”
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Great work.
Can you install an air handler up in a non-insulated attic here in Quebec where night temp often goes down to minus 30? This also would include about 160 feet of flexible ductwork insulated with 2-inch fibreglass leading to 7 ceiling vents into the rooms.
The manual says “for indoor installation only” and I don’t trust the sales rep who says there’s no problem putting the thing “up there”.
Thanks for the info
a worried David
David,
The answer is Yes and No. An electric furnace (air handler) with strip heat will work fine in an attic. Usually the biggest concern is evaporator coil condensate freezing, but I assume AC is not your concern at -30. So, considering the heat, your thermostat will only know that the inside of your home needs to meet your specified temperature. Therefore it will run the unit in your attic until it satisfies that requirement. The problem will come from the invasion of extreme cold at the air handler. At -30, this will be an extreme loss of efficiency due to your run times being longer to finally satisfy the indoor temps that will ultimately result in higher utility bills. Insulating the air handler will help this greatly.
So, your salesman is right. It will work. It just will not be as efficient as it should be.
Good Luck
Home Air Direct
Thanks for super-quick response, but I’m still a bit wary because I’ve been told that the extreme heat loss will ice-up my roof and cause water dams that will let melting snow water seep thru the shingles upwards and flood the attic, walls and eventually the floors along the outside walls.
A building inspector contact says that the lost heat from the ducts will probably release the equivalent of almost 2Kw/h of heat even with the air handler fully insulated…and that within a relatively small open-attic volume will certainly cause severe problems. He also says that in summer when the A/C will be used, the extreme heat up there will damage the roof and undersides even more. Frost, condensation and rust within the handler will manifest itself and shorten the life of the system and the house I fear.
I don’t know the installation company’s reputation, but I feel that when a manufacturer says “for indoor installation only”, there must be a good reason.
Should I play it safe and cancel the offer…I haven’t signed the contract yet?
Thanks again…David