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We utilized a throttling valve on the outlet side of a two-stage gas valve, explained David Spaeth, product manager of heating products, Carrier. The flow is regulated to 40-, 65-, and 100-percent rates to accomplish three stages of heat. Our patented technology then monitors the needs of the home as the unit cycles and adjusts its operation accordingly.
How does the Carrier differ from the York and Rheem modulating furnaces? From what I've read, York has more stages and does all the decision making on the unit board where the Rheem also has more stages but handles the logic at the thermostat.
With three stages is this Carrier significantly better than a two stage Carrier? Is their logic at the system board or the thermostat.