Question about furnace filter - Carrier Infinity 96

Changing filter is like changing oil in the car. Depends on how much you drive, where, etc.

If your furnace runs very little, you have no pets (or children), floors are hardwood, etc. - you're filter will pickup very little dirt. And after all that's what it's for. You can afford to change it less often.

Additionally, you can often vacuum the dirt off or blow it off with compressed air. All messy, but practical. If you can distinguish clean from dirty - by all means look at it and decide.

RichK

What kind of filter, how wide is it. I change a 4" April Air media once a year and its still very clean, my furnace runs little. In my friends house their april air is dirty after a summer of continous AC.

Measure the static air pressure.

Blowing or vacuuming can damage filter media.

You must have not read the post very carefuly - the question was not posted by a tech, but a homeowner. This person may not even understand what static pressure is - who are you trying to impress, besides yourself.

So can evil eye, if it's applied hard enough :-)

Rich

That may all be true, but SQLit offered the only "correct" answer.

Exactly how do I measure the static air pressure?

A manometer is the best way but one doesn't usually have one around the house. One thing that you might have around is a barometer. There are all kinds of these instruments for the house--I guess you would put it in your duct or furnace near the discharge side of the furnace filter. What you weren't told is what reading or pressure drop across the filter is acceptable or unacceptable. For the pressure drop use the difference between the measured pressures from both sides of the filter. MLD

pressure guages are widely available and come at widely varying price points. Used ones on ebay for $10, to new ones direct from mfg on Internet for $200 or more.

The inlet to the pressure gauge is hte plenum leading to the fan, i.e. behind the filter.

We are looking for a pressure differential of a few psi. a 0-10psi guage would work, but 0-30psi is more common. You will need to calibrate by installing a el-cheapo fiberglass filter, and note the reading. Then install a new filter of the type you intend to use and note the reading. When the pressure reading increases ??50%?? ??100%?? its time to change the filter.

Several feet of water? How can you be so wrong so often? :-)

Magnehelic makes appropriate gauges.

Nick

Nick, you amaze me at time. Irritate me VERY very often.

It is a very low pressure differential we are attempting to measure, to be certain. We don't need a 0-25 psi gage, a 0-1 to 0-2 is all we need. Several models in the Dwyer Instrument catalog will do the job.

Access to the specs for the filters is not easy to come by, so I am asking 3M about the Filtrete line of filters.

High efficiency filters 4 inch 5 inch and 6 inches deep often get a differential pressure gage installed to alert homeowners when the filter needs to be changed. Dwyer shows illustrations of such a setup and even includes models with switches builtin to trigger air handler actions when the filters load up.

Our ONLY consideration here is to get a gage what will register the range of pressures we are talking about. The gages you pointed us to will cost us about $70 each unless we can buy them in a secondary market from a distributor.

Perhaps because you are wrong so often :-)

Nick

Both is preferable to neither; but naturally both both and neither is preferable to neither both nor neither; but naturally both both both and neither and neither both nor neither is preferable to neither both both and neither nor neither both nor neither; but--naturally--both both both both and neither and neither both nor neither and neither both both and neither nor neither both nor neither is preferable to neither both both both and neither and neither both nor neither nor neither both both and neither nor neither both nor neither.

from Hare Brain/Tortoise Mind--How Intelligence Increases When You Think Less, by Guy Claxton.

Magnehelic is a BRAND name, like referring to a refigerator as a Kelvinator.

Ok, here is one answer.

So a Dwyer Inst Series 2000 Model 2000-0 0-0.5 inches water will work as will Model 2001 0-1.0 inches water

For some folks, this is not the limiting item, dust and mold spore buildup over time will trigger allergic reactions, and dictate a more frequent filter change interval that max pressure drop across the filter.

These high performance pleated media filters, particularly the 4 inch and deeper models say that they work BETTER, trapping more dust and pollen as they pick up stuff. Also, one useful tip is to always run the HVAC, fan at least, when vacuuming, dusting, or moving furniture so that the filter has a better chance to pickup the dust out of the air as we engage in these activities.

Again, Nick has a really irritating way of saying WRONG.

That's 0.2/12/144x62.33 = 0.00721 psi, and you suggested measuring this with a 0-25 psi meter? :-) If the pointer moved 3" full scale, it would move less than 0.001" across this filter, so once again, your suggestion is utterly useless.

Nick

We needed a calibration point and you IGNORED the rest of what I said in the message concerning the Filtrete filter. Yes the pressure drop is far less than what a 0-25psi gage will show. OK, we need a 0-1.0 inch water pressure gage.

However, for $14.99, you can get inexpensive gages that will hang up to

In article , " snipped-for-privacy@yahoo.com" writes: |> I'm wondering how often to change this filter. It's huge and very |> expensive. I'd hate to change it more often than necessary. The |> installer said every six months. |> |> I sent an email to Carrier and they told me once a month. That sounded |> ridiculous to me. The documentation says to look at it at least every |> six months and change it at least once a year. |> |> Can I just look at it and know when it needs changing? |> |> As you an tell I'm a novice at this so help would be appreciated.

I have a Carrier Infinity 96.

What type of thermostat do you have? Is it an Infinity controller?

My first filter lasted about a year before I got the message.

Robert

This alert is a function of a 'reminder' system/program preset in the chip, rather than any kind of sensor. Look at it monthly..If its a cheap fiberglass type, replace it. For under $

Hi, My house has EAC mounted on the return air duct. No other filter at all. Clean the element in the dish washer twice a year. Works well.

Yes I have an Infinity Control but the reminder is based on timing and not on whether it senses the filter is dirty or not.

How much do you pay for your filters? This filter is SO much bigger than the ones in our old furnace that we are worried about cost.

The filter is an aftermarket item. The furnace itself does nto come with a filter, so the dealer has a choice when installing the furnace, what filter to install.

Many dealers will go with a 4" pleated filter as they make an extra $100-$200 profit in selling this filter.

Replacement filters cost between $35 and $60 depending on the source and the size of the filter. Filters-Now.com sells all sizes and shapes, 3M and many other brands!!

You will need to look on the case that houses the filter to determine brand of the filter, then slide it out to get the size and part number