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.
Gary ~ AB9M
From: Howard Lester <email@example.com>
Sent: Friday, May 11, 2018 5:50 PM
To: GARY HUBER
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.
Is there a variable speed furnace fan that has a high, medium, and low speed
Variable Speed ECM Blower Motors | Air Handler Air
Variable Speed ECM Blower Motors these motors increase efficiency of the
systems and offer a whole range of other benefits that help the system
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.
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