From: Brent Brown <brent@eds.co.nz>
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Date: Mon, 28 Jun 2021 17:25:39 -0700
Subject: Re: [EE] HVAC filter efficiency and energy consumption
Thread-Topic: [EE] HVAC filter efficiency and energy consumption
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Hello Mark,

Once upon a time I worked on a ventilation system for houses that pulls dow=
n=20
warm/dry air from the roof space and pushes out cold/damp air from inside t=
he=20
house. The idea somewhat works some of the time, but that's another discuss=
ion.

But the part that relates to your filter/energy consumption question... the=
 ventilation=20
system had a fine grade air filter and we sought to see if we could measure=
 its=20
condition (new/clean/free-flowing vs old/dirty/blocked). One would assume t=
here=20
would be a detectable difference in fan speed or power, and we sought to de=
tect &=20
indicate when the filter needed to be changed.

Fan RPM was the easiest data to obtain, but that alone showed no definitive=
=20
difference between clean and dirty filters. Likewise fan current offered no=
 clear=20
correlation. Fan power we did also try... but from memory that also did not=
 offer the=20
clear picture we desired. Adding air pressure sensors before and after the =
filter=20
might allow a reasonable correlation to be made, but that adds some=20
cost/complexity.

On 28 Jun 2021 at 7:51, Mark Howles wrote:

> Hello,
>=20
> I was contemplating changing my Air filters to MERV11 and was told by som=
e
> people that they are bad for energy usage and air flow. I came across a
> study that measured and compared the effects of low efficiency and high
> efficiency filters and I found the technical details fascinating. Their
> conclusion was that effects are not significant in residential settings.
>=20
> Does anyone have experience with this, or have monitored this before on
> their own?
>=20
> I thought of just correlating energy consumption increase/decrease around
> the initial few days of installing  the filter, at similar temperatures,
> though the paper suggests there can be a complex interaction of many
> variables before coming to conclusions.
>=20
> Here is a link to the Study:
> https://www.caee.utexas.edu/prof/novoselac/Publications/Novoselac_ASHRAE_=
Transactions_2010.pdf
> --=20
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
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--=20
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