How to inspect furnace filters?

[Don Y]

(sigh) You truly don't get it, do you? A percentage is a *portion*; a likelihood. It has nothing to do with a common-ness... a frequency... which is a "per unit time" measurement.

My *chance* (likelihood) of being murdered (or, *anyone's* chance of being murdered) is a probability. OTOH, the *frequency* of murders in a community is a number of events per unit time. It is a separate and independent metric from "probability".

A city with 100 million population may have a murder rate (likelihood, probaility) that is effectively *zero* (0.0001%) yet have a murder EVERY NIGHT on the evening news! It is a COMMON occurrence. It happens FREQUENTLY!

A city with 1000 population may have a murder rate that is much, much higher! Maybe *1* percent (i.e., 10,000 times MORE LIKELY), yet murders happen

*monthly* rather than *daily*. It is far less COMMON. Yet, living in that city is much RISKIER than the first city! You are 10,000 times more likely to be one of those monthly victims than one of the DAILY victims in the first location!

If you're thinking in terms of percentages, you're on entirely the wrong track! Percentages have no concept of time -- of FREQUENCY! ("per unit time")

[clare]

And what does all this drivel have to do with inspecting furnace filters?????

[Don Y]

If you'd read up-thread, you'd see it a consequence of debating the replacement schedule for said filters...

[clare]

I don't replace mine. I have a washable electrostatic filter (not a powered unit) that fits in place of the 1 inch pleated filter. I wash it every couple months, shake it dry, and put it back in place. On the old furnace I had the replaceable depth filters - I used a filterfresh spray on them that made them sticky so they caught more of the fine stuff like polen etc. I had electrical discharge electrostatics in my previous house - they were MISERABLE to clean - they'd get blacker than black - pretty well needed a dishwasher dedicated to cleaning them

[DerbyDad03]

Oh, I get now. You can use your percentage of 70% to Vote "Yes" on commonness, but I can't use 9.2% to vote "No".

Does this sound familiar?

You: So, in response to your comment, below: Me: "Common? Until I see the numbers, I'll vote No." You: I vote *yes* (70% of the fires!) -- unless you'd care to offer some OTHER numbers?

Like I said, but neglected to do...moving on.

[Don Y]

The percentages pertain to ACTUAL FIRES! You can count the number of ACTUAL FIRES in any particular time period. From that (events per unit time) you get FREQUENCY OF OCCURRENCE. Has nothing to do with how LIKELY a home is to catch fire! I'm looking at a PORTION (percentage) of a FREQUENCY. So, it's a measure of "common-ness".

That's the only NUMBER you are going to get -- there are no "smoke detector police" who will check every residence to see *if* they have a detector and

*if* it has batteries and *if* the batteries are operational. *But*, the cited report indicates the portion of those ACTUAL FIRES that had battery powered smoke detectors that DID NOT OPERATE (20% of those fires). Of these ACTUAL FIRES in which BATTERY POWERED DETECTORS failed to operate, 70% of those were the result of missing, disconnected or dead batteries.

Do the math and you can see that this isn't a small number -- IN A GIVEN PERIOD OF TIME (ha nothing to do with the likelihood of a fire!). As such, it is COMMON.

Chance of winning the lottery is essentially ZERO -- 0%! Yet, someone ALWAYS seems to win! So, winning is COMMON -- but not LIKELY!

This is why so many folks are suckers for gaming machines; failing to understand what the numbers *mean* and reading more (or less!) into them than the actual math implies!

[Don Y]

We simply replace ours every month -- toss the old unit in the trash. In the summer, it's filtering stuff running through the air conditioner's A-coil; in the winter, it filters stuff that is running through the furnace's heat exchanger. Roughly the same total volume of air in each case.

The swamp cooler makes things worse when we opt to run it as it brings outside air directly into the house (through a very porous "wet" filter). But, it is impractical to filter as it moves many thousands of cubic feet per minute.

I've seen homes (smokers) with electrostatic air filtration that had "smoke-plated" walls (remove the picture frames from the walls and you can see where they *were*.

[clare]

We run the fan on low all year,the AC only on the hottest most humid days ( a couple weeks every summer). The AC runs the fan about half again as fast as theheat cycle.

[Don Y]

Our cooling season starts in April and ends in October -- we're still seeing

100F temperatures. The cooler is an excellent device during the dry months (April, May, June, October, November) but brings lots of "dirt" into the house (as there is often airborn dirt: google "haboob") as well as pollen (we have essentially a continuous growing season). When using the cooler, its fan essentially runs continuously (low vs. high, maintained automatically by the thermostat) as turning the fan *off* allows hot air to blow *into* the house (you need to leave windows cracked open for the cooler to function as it works by *replacing* the air in the house, continuously). The cooler keeps "positive pressure" in the house to prevent hot, dry air from outside infiltrating through those open windows.

In recent years, we have opted to just run the ACbrrr continuously instead of having to deal with *removing* the humidity that the cooler injects into the building (e.g., doors swell, bath towels "never dry", carpet feels wet, etc.).

During the rainy parts of winter, the ACbrrr comes on, again, despite moderate temperatures -- mainly for dehumidification.

[ItsJoanNotJoann]

Excessive chatter deleted.

Well, I do.

I don't suspect what other people do with their smoke alarms. Not my business.

More chatter deleted.

I don't "discover" the filter needs to be changed. Remember, I said I write it on my calendar. Also, I DO keep spare filters on hand, just like I keep spare batteries on hand for the smoke detectors and those batteries are also used for clocks and remotes.

[Stormin Mormon]

As I've been saying, it's a judgement call. I like to replace them when it looks like the dust and dirt might be slowing the air flow.

- . Christopher A. Young learn more about Jesus .

. .

[Stormin Mormon]

Cuts down on trips to the store, to stay a bit stocked up.

- . Christopher A. Young learn more about Jesus .

. .

[Bill Gill]

The biggest problem with staying stocked up on batteries is that it is getting harder and harder to find a pack of batteries that qualifies, at least to me, as 'that will be enough to keep me going for a little while'. The packs are getting bigger and bigger.

Bill

[Don Y]

We don't need to "write it" -- just remember to replace it the first of *every* month.

Our clocks and remotes use AA or AAA batteries. As do many of our flashlights, "digital" magnifying glasses, cordless keyboards and mice, etc. So, those are all outfitted with rechargeable NiMH cells while a set of 4 of these remains in a charger at all times (if any device's "batteries" falter, throw *those* in the charger while taking the ones *from* the charger for the device in question). If more than 4 cells fail at the same time, we'll be inconvenienced for an hour or so while the charger tops off those "other" cells. Four "extra" cells to support all those devices (instead of a package of 20 "spare" alkalines.

Everything else uses some sort of "specific" rechargeable battery: the PDAs, cordless phone, cell phone, gyromouse, UPS's, iPods, BT earpieces, electric wheelbarrow, cordless vacuum, cameras, the oversized flashlights with built-in chargers and various scientific instruments.

[We have a LOT of battery powered devices, here. With batteries ranging in size from fingertip to "car battery" and costs from pennies to hundreds of dollars. Hence the BIG appeal of *rechargeable*]

This leaves the 2 maglites (3xD cells), the coleman floodlight (8xD), the "CMOS batteries" in the computers and keyfobs, and the smoke/CO detectors (9V).

With three of these flashlights (not counting the ones that are miniature suns), one can always treat two as "spares" in the event that the batteries in one die -- off to the store at our leisure! Computers and key fob batteries fail so very infrequently and with a significant warning so picking up another "coin cell" is no big deal.

That leaves the smoke/CO detectors -- which have the annoying trait of "complaining"/annoying *when* they die. Simply don't *let* them die!

[Don Y]

Planning on replacing particular batteries at particular times (instead of letting the device complain when *it* wants the battery to be replaced) means you can buy what you need and *when* you will need it. Instead of finding a place to *store* (isn't that what "stores" do?) those additional cells!

Costco has some eneloops going on sale...

[DerbyDad03]

Color me confused.

You can buy batteries in packs of as little as 2 or 4, all the way up to the bulk packs or 24, 36+ with more options in between.

Is there no combination of those sizes that will fit your needs?

[Bill Gill]

what I am talking about is the fact that the packages they come in are growing. It used to be you could buy packs of

2 AA cells. Then it went to 4, not you are lucky to find a pack of 8. I prefer to keep enough on hand replace the batteries in one remote, and get more when I run that bunch down.

Bill

[Bill Gill]

Have you been shopping for batteries lately. Where I have been buying them, Walmart, Target, etc. They don't have the 2 and

4 packs anymore.

Bill

[Vic Smith]

What helps is eliminating D and C cells. I don't use my D cell Maglites any more, and probably will plain throw them away soon. I use AA and AAA for all my flashlights. LED. PC keyboards, mice, remotes use the same. I use some remaining Eneloops, and Sony NiMH, with 2 Sony chargers. One loaded with AA, the other AAA. Still have to pick up some buttons and 9v occasionally. But I resist buying anything using other than AA or AAA.

[Don Y]

Yes. Even if you *can* find a "small package" that isn't "stale" -- because no one seems to want to buy in small lots (I recall Leno joking that Costco is now selling caskets! But, you've got to buy *6*...) -- you end up having to buy the tiny packages at places that are outrageously priced. Like "the qwikie mart", a *clothing* store, etc.

So, why buy 2 when you can buy 12? Ans: cuz then you have to *store* 12 -- and, hope they actually work when/if you need them ("Gee, I *thought* I bought some of these a while ago... where did I *put* them?")

The AA/AAA rechargeables are less of a problem for us. We have one of those tiny chargers that holds *just* four cells and hangs directly off the electric outlet. So, we know exactly where our "spares" are stored.

I have bigger/fancier chargers that will charge 8 D's, AA's, AAA's

9V, etc. But, we have so few things that use anything *other* than AA and AAA that its foolish to purchase those sizes -- and leave them sitting on/in/near a charger for the year or so it might take for that *one* device to need new batteries! [The AA/AAA see lots of turnover because *something* always needs new AA/AAA batteries!]