[RFI] Ruud Furnaces and AC units

[Gene Smar]

I may have started the thread 2 years ago. I had asked for similar advice on replacing my fire-damaged heat pump. I was concerned about RFI from ECM devices in modern energy-efficient heat pumps.
IIRC, the general concensus was that ECMs with their computer-controlled continuously variable speeds would be more likely to cause RFI than motor controllers that operated at discrete speeds, i.e., without computer controls. Accordingly, I went with a two-speed system vs variable. 
Word of caution: these discrete speed systems are not as efficient as variable speed ones, due to their limited ability to match air flow to demand based on room temperature. My new Goodman brand system is rated 14.2 SEER2, barely on the scale on the EPA required label.
73 de Gene Smar AD3F 
Sent from my Radio Shack TRS-80 model 100 laptop 
 
  On Sun, Jul 6, 2025 at 9:08 PM, Steve London<n2icarrl at gmail.com> wrote:   There was a thread on this very subject about 2 years ago. Check the
archives.

73,
Steve, N2IC

On Sun, Jul 6, 2025 at 6:30 PM Dan K2YWE <dan.k2ywe at gmail.com> wrote:

> Electronically Controlled Fan. I'm not so sure. The are some in high end
> Carrier AC/heat pumps that some local hams have reported as EMI quiet.
> Probanly some other brands too.
>
> 73, Dan
>
> On Sun, Jul 6, 2025, 3:51 PM Jim Brown <jim at audiosystemsgroup.com> wrote:
>
> > What's an ECM fan?  If it's variable speed, it's almost certain to be
> > noisy.
> >
> > 73, Jim K9YC
> >
> > On 7/6/2025 8:54 AM, Dan K2YWE wrote:
> > > Is there any group knowkedge with respect to RFI from Ruud oil furnaces
> > and
> > > AC units that have ECM fans?
> >
> >
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> >
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