Doc,
I have a high efficiency Rheem furnace, going strong for 10 years. The
only RFI I get from it is during ignition of the burners ( a burst of
"machine gun static" for about 2 seconds). The burst is audible on all
bands 160m thru 6m on any HF or 6m radio. (No antenna is closer than 50
feet to the house.) The burst is not real loud and it is of short
duration, so I am willing to live with it. The furnace motors (air
handler and combustion blower) are both AC induction types. My high
efficiency A. O. Smith gas-fired water heater causes no RFI at all. It's
located near the furnace, but I think it uses a hot plate method for
ignition, rather than a spark. Its combustion blower is also an AC
induction motor.
As a side note, the church I attend has 8 high efficiency A/C-Heat Pump
units that were installed early last year. While we don't have any radios
there, we do have a sound system with lengthy (150 feet, or longer)
microphone cables. I had some reservations about these new units because
they all employ inverters with variable speed blowers and compressors. Low
impedance mic lines do offer a lot of common mode noise rejection, but the
building is old and I have no idea as to just how good (or not) our
grounds are at the various power outlets. In any event, whatever noise is
created by those 8 units is not showing up in the sound system, and I'm
glad of that.
73, Dale
WA9ENA
"doc@kd4e.com" <doc@kd4e.com>
Sent by: rfi-bounces@contesting.com
10/27/2010 02:04 PM
Please respond to
doc@kd4e.com
To
dalej <dj2001x@comcast.net>
cc
RFI List <rfi@contesting.com>
Subject
Re: [RFI] RFI from new Hi-efficiency furnace?
Hey Dale and Mel,
We will be looking at HVAC units soon as well.
I'd be interested in what sort of tests you have done -
Dale (bands, modes, type of gear) - and what is the proximity
of the antennas to the HVAC.
Also, do you know where the Carrier equipment is
currently
manufactured? (I know it can change from year to year.)
> We have a Carrier Infinity and it has the DC fan motor which runs at
> different speeds for A/C and for just circulation. I have not
> experienced any noise from it.
>
> 73 Dale, k9vuj
--
Thanks! & 73, doc, KD4E
http://KD4E.com
Have an http://ultrafidian.com day
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