[RFI] Comments on RFI from Ductless Air Conditioning Units?

[W2RU - Bud Hippisley]

Go back into the archives for a series of postings relating to RFI from PWM drives for blower motors in residential heat pump / air-conditioning air handlers -- starting with my posting on April 10, 2010 and going through April 14th of that year.

Bud, W2RU

On May 8, 2013, at 8:03 10PM, qrv at kd4e.com wrote:

> I'd ask them for one or more locations where you might see them
> in action ... and bring a radio or two ...
> 
>> On Wed, May 8, 2013 at 7:13 PM, qrv at kd4e.com <qrv at kd4e.com> wrote:
>>> If I am thinking of the same units as he is they pipe the freon
>>> around the house along with the AC voltage and control lines.
>> 
>> Pretty close.  The indoor units are actually DC but you have the right
>> idea.  Here is an example of what I'm talking about:
>> http://www.daikin.com/global_ac/products/residential/
>> 
>> Both inverting (PWM controlled compressors) and non-inverting models
>> are available.  My impression is that the change to PWM controlled
>> compressors is not unique to ductless systems.  It's happening across
>> all types of air conditioning to reduce compressor cycling in an
>> effort to increase overall efficiency.
>> 
>> It would be a shame to make such a significant purchase only to
>> introduce more RF noise.
>> 
>> -Jeff
>> W7WWA
>