
4000705 – REDUCER
10226 Plano Rd, Suite 104, Dallas TX 75238
Questions? Call or text (214) 340-9421
Mon–Fri 10 am – 7 pm | Sat 10 am – 3 pm
A duct reducer transitions between two different round duct sizes in your supply or return air system. Use one when you need to connect a 7″ duct run to a 5″ branch, or when stepping down from a trunk line to a smaller run. Galvanized steel construction holds up in attics, crawlspaces, and walls.
Specs: 7″ to 5″ round duct reducer, galvanized steel, crimped on small end for slip-fit connection
Replaces: 4000705
Fits: Standard 7″ to 5″ round ductwork. Universal fit — works with all HVAC brands and systems.
In stock at Open To Public HVAC Parts in Dallas. We test parts at the counter before you buy. Call or text (214) 340-9421.
Cross-reference numbers
This part replaces the following OEM and aftermarket numbers:
- 4000705
- 40075
- ELKHARTCOPPER
- ELKHARTCOPPERFITTINGEQUIVALENT
- MUELLERCOPPER
- MUELLERCOPPERFITTINGEQUIVALENT
- SMITH-COOPERBRASS
- SMITH-COOPERBRASSFITTINGEQUIVALENT
Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.




