Not necessarily. Some multi speeds switch windings and/or capacitors. Ceiling
fans are multi speed with nothing but different capacitors in the same
enclosure.
Jim
K4QPL .
Sent from my iPhone
> On Nov 11, 2024, at 2:39 PM, Steve London <n2icarrl@gmail.com> wrote:
>
> Why would a multi-speed device be much quieter ? It's still changing the
> frequency to control the motor speed, isn't it ?
>
> 73,
> Steve, N2IC
>
>> On Mon, Nov 11, 2024 at 10:47 AM Dave (NK7Z) <dave@nk7z.net> wrote:
>>
>> Think of a variable speed fan controller as an automatically controlled,
>> dirty 500 watt square wave generator, connected to a long non twisted
>> wire, running a motor... They are quite noisy...
>>
>> I have a neighbor that has one, (probably 70 feet from my antenna), and
>> he used to run it 7 minutes on, 7 minutes off to clean his home air. I
>> asked him if he could change that to as needed, and I now have 17, 15,
>> 12, and 10 back, when it is not running, which is most of the time...
>> He has two Carrier units, and they make zero noise.
>>
>> His Mitsubishi unit is the culprit in the RFI generation. The model
>> number is:
>>
>> SUZ-KA12NA
>>
>> The installer has no idea of what RFI is...
>>
>> 73, and thanks,
>> Dave (NK7Z)
>> https://www.nk7z.net
>> ARRL Volunteer Examiner
>> ARRL Technical Specialist, RFI
>> ARRL Asst. Director, NW Division, Technical Resources
>>
>>
>>> On 11/11/24 08:40, Dan K2YWE wrote:
>>> Thanks Jack.
>>> Do your units have variable speed or multi-speed fan control?
>>>
>>> 73, Dan
>>>
>>>
>>> On Mon, Nov 11, 2024 at 11:10 AM Jack Ference <jackference@gmail.com>
>> wrote:
>>>
>>>> Hi Dan,
>>>>
>>>> Both Frank W3LPL I have had good luck with Carrier. He replaced one unit
>>>> as nd replaced two a few years apart.
>>>>
>>>> I bonded the cabinet door to the sides, installed a powerline choke on
>> the
>>>> power to the blower motor and installed a coil of wire choke around the
>>>> thermostat wires.
>>>>
>>>> I opted for one step down from the highest efficiency units so the
>>>> compressor had switched settings rather than variable settings
>> controlled
>>>> by electronic circuitry.
>>>>
>>>> Carrier was aware of my concerns and supplied the documentation for the
>>>> fixes. They happened to be the same fixes I did on my first unit
>> replaced.
>>>>
>>>> Jack W3KX
>>>> Sent from my iPhone
>>>>
>>>>> On Nov 11, 2024, at 10:56 AM, Dan K2YWE <dan.k2ywe@gmail.com> wrote:
>>>>>
>>>>> I'm need to replace my 25 year old HVAC with a new oil furnace and AC
>>>>> system.
>>>>> EMIis a great concern. It's a small house and efficiency is of little
>>>>> importance.
>>>>> What are the recommended brands and/or models?
>>>>>
>>>>> 73, Dan
>>>>> _______________________________________________
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>>>>> RFI@contesting.com
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