Timeline for Would retro-fitting a DC motor as the blower motor in a residential furnace be more efficient than existing 1/2 hp AC motor?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Oct 5, 2021 at 0:27 | comment | added | user57037 | I think ECM means electronically commutated motor. If so, that is a logical description of a BLDC motor. | |
| Oct 4, 2021 at 16:05 | comment | added | manassehkatz-Moving 2 Codidact | We often have "X Y questions" - e.g., "how do I replace an AC motor with a DC motor" without any context would likely result in comments of "What is the motor being used for?" because that can have many ramifications. So knowing it is a furnace is good. Knowing more about the type of furnace (gas, standing pilot, etc.) is very helpful and should be added to the question so that everyone knows the parameters. | |
| Oct 4, 2021 at 16:03 | comment | added | Peggy Schafer | See, I didn't want this question to devolve into a discussion about furnaces. The furnace is standing pilot (extremely small flame, hardly of any consequence from an energy / cost point of view), no electronics, thermostat (which is electronic) is powered by a pair of AA batteries. 24VAC comes from step-down transformer, easily powered by moderate-sized UPS for a day or so. | |
| Oct 4, 2021 at 16:01 | comment | added | user80875 | @Peggy Schafer, brushless, permanent-magnet motors can be stepper-motors, synchronous motors or BLDC motors. (I have never heard of ECM motors). A lot of the difference among the types is in the control method, but there are also details of the rotor design that differentiate one type from another. It is possible to configure a controller to operate a permanent magnet synchronous motor as a stepper motor and to transition while running between two modes of operation. | |
| Oct 4, 2021 at 15:59 | comment | added | manassehkatz-Moving 2 Codidact | standing pilot - that is inefficient and has not been typical in new furnaces (at least in my part of the world) for a very long time. | |
| Oct 4, 2021 at 15:46 | comment | added | manassehkatz-Moving 2 Codidact | A typical residential furnace, in my experience, has a lot of complex electronics - and has for many years. Igniter. Solenoid. Sensors for flame, overheating, airflow, etc. Even "24 VAC for gas solenoid" needs to come from somewhere and be controlled by something. | |
| Oct 4, 2021 at 15:19 | comment | added | Peggy Schafer | I was under the impression that BLDC was more frequently known as ECM motors (at least in the HVAC industry). If I'm not mistaken, they are essentially stepper motors, and yes they have double the efficiency of an equivalent shaded pole AC motor, but they are pretty much impossible to obtain as they are not sold as replacement or "drop-in" motors in hardware and industrial stores the way that PSC and shaded pole motors are. | |
| Oct 4, 2021 at 15:16 | comment | added | Peggy Schafer | The focus on the perceived issues with the fact that this is a furnace is not necessary nor useful for answering this question. I should not have to explain this, but this is a very simple furnace, standing pilot, no electronics, no draft motor, requires only 24VAC for gas valve solenoid. In the event of a power failure, only the blower motor (horribly inefficient 1/2 or 1/3 hp shaded pole) is what prevents furnace operation. | |
| Oct 4, 2021 at 15:01 | history | answered | manassehkatz-Moving 2 Codidact | CC BY-SA 4.0 |