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

[Roger (K8RI)]

On 5/12/2013 1:37 PM, Jeff Stevens wrote:
> Has anyone had success specifying a term such as 'RFI Free' when
> dealing with a contractor?  Whenever there is AC (or worse yet, square
> waves) there is going to be SOME level of RFI, no?  The question
> becomes what level is acceptable for a particular installation.  In my
> case, if it's VLF/ELF noise or HF noise below the noise floor on
> antennas some distance away, I don't really care.  I can't, however,
> provide a more specific acceptable level such as a particular maximum
> field strength.  Something like 'RFI Free' seems rather amorphous and
> if I were a contractor, I'd be reluctant to accept such a term.
> However, if my customer provided concrete criteria (such as a maximum
> field strength) I might actually be able to get some specs from the
> manufacturer and have some reasonable confidence that I can perform
> the install in such a way as to meet my customer's needs.
>
> Just curious if anyone has brought RFI issues up, in writing, with a
> contractor and how that worked out.

When I was looking at installing a geothermal unit there was not one 
contractor who would agree verbally let alone in writing.  I was under 
the impression most didn't even understand what pulse width modulation 
meant or how the motors we actually controlled.  Even those that would 
listen didn't appear to understand how it could interfere with a radio 
because it was on a wire.

Our house is well insulated and the only thing I'd change beside making 
it 50 - 100% larger would be to increase the pitch of the roof 
substantially.  It turned out that the latest geothermal system would 
have a payback of 47 years compared to our old, high efficiency system 
that is ready for replacement.  47 years is about twice the life 
expectancy of the installation.

They all had to see our gas and electric bills before they'd believe our 
heating and cooling costs.  To a contractor they all agreed that 
geothermal was not worth the investment for us after working months to 
get us to consider it.

73

Roger (K8RI)


>
> -Jeff
> W7WWA
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