[RFI] What Does Variable Speed Mean?

[GARY HUBER]

I understand what " continuously variable" means and the Variable Speed ECM Blower Motors are not operating in "discrete steps" but are rather programmed for upper limited RPM speed for "Low, Medium, or High". These motors in fact drop speed during burner, heat coil or condenser coil operation, so that the air plenum and duct work are working at maximum efficiency.


Besides owning several Carrier Infinity systems with Variable Speed ECM Blowers, I worked in HVAC for almost ten years many years ago. Maybe my understanding of a “variable speed fan" is different than yours or Jim.

73,
Gary ~ AB9M
________________________________
From: Howard Lester <howard220 at gmail.com>
Sent: Friday, May 11, 2018 5:50 PM
To: GARY HUBER
Cc: rfi at contesting.com
Subject: Re: [RFI] What Does Variable Speed Mean?

What Jim is describing as a “variable speed fan,” in the context of RFI production, is one that is continuously variable, not one that has speeds  controlled in discrete steps. See below what I excerpted from his explanation.

Howard N7SO


Is there a variable speed furnace fan that has a high, medium, and low speed setting?.....

Yes.....

See <https://highperformancehvac.com/ecm-blower-motors-2/>
[https://www.bing.com/th?id=OVP.eUnoqSz-eoNERnwaQ2OO2gEcEs&pid=Api]<https://highperformancehvac.com/ecm-blower-motors-2/>

Variable Speed ECM Blower Motors | Air Handler Air Flow<https://highperformancehvac.com/ecm-blower-motors-2/>
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Variable Speed ECM Blower Motors these motors increase efficiency of the systems and offer a whole range of other benefits that help the system





73,

Gary ~ AB9M



 on behalf of Jim Brown

 Think of a
variable speed motor as being more like a volume control, so its speed
can be varied over any value from zero to high.