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Variable speed AC air flow

I recently had a Lennox iHarmony variable speed system installed. Was working great, however, they did not correctly install the dampers. They came back and fixed the dampers, however, it now feels like we do not have the benefits of a variable speed system. The air is either blasting out or the system is off.

The Blower CFM Demand appears to only have 3 levels - 0, 1066 and 1300. After it runs at 1300, it cuts back to 0 until it turns on again. Cycle is 0, 1066, 1300, 0.

I was expecting a lot more variability in air flow to maintain a constant temperature. Are the above numbers reflective of a system working correctly?


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    You'd need to provide a lot more numbers.
    Was it sized properly? Is it the proper duct work?
    Was it installed properly?
    Was it commissioned properly?
  • pedmec
    pedmec Member Posts: 938
    sounds like the profile for the blower is set for single stage in cooling but you need to supply a model number for the furnace and condenser to know what we are dealing with to give you accurate information.