As has been stated many times, variable speed drives are highly efficient,
are quieter, and save a lot of electricity. The old single speed units are
being phased out. The byproduct is any variable speed drive, whether an
HVAC, pool pump, or other appliance can create RFI simply due to the
inherent method of speed control. However, some have some internal
filtering (low end models tend to cut corners) and on others the beast can
usually be tamed. The RFI which almost always is using the house wiring as
the transmitting antenna, can be reduced by installing a line filter as
close as possible to the drive (motor) as possible. I have used the
Schaffner filters, available in the right amperage from Mouser and others
to tame variable speed pool pumps. My top of the line Carrier HVAC system,
also variable speed, doesn't create enough RFI to bother me. The compressor
is not usually the emitter, but the air handler fan motor often is. Part of
that is simply proximity to other circuits. Try to determine which is the
source. Determine the current draw of the specific motor and convince the
installer to pay for the filter and install it for you. Don't take any BS
about it voiding your warranty. The proper line filter gives "cleaner"
power to your unit and may protect it from other line surges. You may have
to escalate from the field tech to the senior tech who holds the company
license. If your HVAC company doesn't understand that and can't take care
of it, escalate to the manufacturer or distributor citing the FCC regs and
look for another service company. Best to negotiate that before you place
the order.
73,
Jim K4QPL
On Wed, Jun 16, 2021 at 7:30 PM Don Kirk <wd8dsb@gmail.com> wrote:
> Hi John,
>
> Go search the RFI Archives at http://lists.contesting.com/_rfi/
>
> I did a quick search on the term HVAC and there is a long list of postings
> on this subject. I quickly found one that indeed documented a problem:
> http://lists.contesting.com/archives//html/RFI/2021-01/msg00026.html
>
> I'm sure you will find more if you dig through the RFI Archives.
>
> 73,
> Don (wd8dsb)
>
> On Wed, Jun 16, 2021 at 7:02 PM John Altman <wa4aip@gmail.com> wrote:
>
> > Hi Group,
> >
> > Is there anyone in the group who has knowledge or experience with RFI on
> > the subject HVAC system?
> >
> > I cannot find any evidence of indeed there are issues.
> >
> > If so, I will appreciate your input!
> >
> > Thank you,
> >
> > John
> > WA4AIP
> > ARRL Charter Life Member
> > 50 Years HAMMING!
> >
> >
> > Sent from my iPad PRO
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> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
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