Tuesday, July 15, 2008


Beautiful in nature... not so much in your utility closet; though honestly we're talking more like cascading sheets than so much a "fall".

Lemme splain...

First, for those not in the know about our local climate; here in AZ we are generally among the driest climates in the world; however for two to six weeks twice a year (in the spring and fall), we have generally quite heavy daily rain, and thunderstorms.

This we call our "monsoon"; and while certainly nothing in comparison to the south Asian phenomenon from which it draws its name, we can see a few weeks at 85% relative humidity, and some days receive as much as 8 inches of rain (and two inches is not uncommon).

Just as an example, as I am typing this, it's just before 9am, just under 90 degrees, and about 60% relative humidity outside (and quite cloudy). Three weeks ago, before the start of the current trend line, this same time of the morning would have seen somewhere between 100 and 105 degrees, and between 5% and 15% humidity.

Thankfully due to the wonder of air conditioning, my office is a lovely and cool 72 degrees and 36% relative humidity.. technically, just about perfect for an office environment given the electronics etc...

So I've mentioned before, I live in a 55 year old house, poorly insulated with original doors and windows (yes I'm working on changing all that); and as of last September, a new but undersized ( for the house, area, and insulation level - thank you home warranty company, who ONLY size by the square foot without considering any other factors) air conditioning unit.

Basically the AC runs 24/7 from May through September (with the old AC unit it was from April through October) ; and some time in June we turn on our supplemental in wall unit. We also have a third portable unit we can wheel out if we need to.

Yup, we take our AC seriously here.

We had our ducts and air handler cleaned and sanitized last month; one, just because they were all crudded up and needed it badly; but also because we knew the monsoon was coming, and we wanted to have the thing cleaned out and sanitized when the humidity hit, to avoid mold problems (the dust is REALLY bad here, and it carries heavy loads of mold spores. Any humidity or dampness anywhere, and there's mold INSTANTLY).

Unfortunately, over the last few weeks, since before we had our ducts cleaning in fact, the AC performance has been poor. It just hasn't been keeping up. Since this is our first year with this AC unit, and the old unit was far worse; we just assumed that it was because the unit was undersized and the house was under insulated. Doing the duct cleaning helped a bit, as airflow and air quality improved significantly; but the air just wasn't as cold, nor was there as much of it as we would have liked.

As the humidity has increased, this problem has become worse. This is of course to be expected, because the AC has to work harder as the humidity increases; but I was starting to suspect something was wrong.

Also as the humidity increased, I started seeing some condensation on our tile floors. This is normal for this house; having a tile floor that can be 20+ degrees cooler than the surrounding air, right in front of the poorly insulated closet where the AC air handler unit sits. It seemed there was an excessive amount of it this year however.

Well, last night, as I went to bed, I noticed the airflow out of the AC ducts... or rather I noticed the almost total lack of it.

I figured the air filter had clogged up (it was brand new a month ago, btu as I said, we have a severe dust problem here), and went to check it. I shut the AC and fan off, and the first thing I heard was the sound of flowing water. Now a little tiny trickling is normal when you turn the AC off on a very humid day, condensation being what it is; but this was no trickle., It sounded like a babbling brook.

The next think I noticed now that the roar of the AC unit was gone, was the tiles in front of the AC closet went "squish" when I stepped on them.

Tiles are not supposed to go "squish".

Awww crap.

So I opened up the AC closet; and the air handler unit is sitting in about 1/2 inch of water.

Oooh boy.

I pop off the covers, and water is just POURING down the insides of the air handler; and pooling up anywhere it can; making little waterfalls inside my climate control system.

Nowhere near as pictureseque as they are in nature; especially when live AC lines are submerged.

When I changed the filter after the duct guys came, I noted there was a little moisture around; but it wasn't a huge, or abnormal amount. Well, since then not only ahs the amount become abnormal, but apparently it's been there long enough to grow algae. Oh yes, this water was slimy.

So of course I unplugged the air handler immediately, and grabbed my wet dry vac.

I should note, this is at about 1am by the way.

I sucked out what standing water I could, sprayed the whole thing down with dilute bleach, and started checking for leak sources.

Hmmm... not so much sopurces as one big general leak really. Every seam of the air hundler had water seeping from it.

I felt up the heat exchanger duct work, and instead of being flexible and hollow; and slitghtly cool, it was icy, and absolutely rigid.

Oooh boy fun.

In the humidity, my heat exchanger had not only built up an ice dam, the whole thing WAS an ice dam. Seriously, the entire 2 cubic feet was one big ice cube.

No wonder there was no airflow.

Next step, check and see why the condensation drain isnt draining. I snaked it up from the outside, and it was clear, so I had to get my recip out and cut the air handler end; and there was nothign but a trickle coming out the drain.


I slid my snake in there, and in just a few inches I pushed through an obstruction and water started GUSHING out the drain like a faucet.

Thankfully I had my wet dry vac right there, and I started sucking that water out, while I I finished snaking. Then I went around and closed all the vents but one, kicked the furnace on to high, and held the vac on the end of the condensation drain for a full half hour; actually having to empty the vac in the process.

Yes, it filled my shop vac. Actually it almsot filled it twice.

Once the giant ice cube had melted, and the whole house was up to 80 degrees and 80% humidity (not quite that bad but almost) I temporarily reconnected the air handler to the drain line with duct tape, and switched the AC on; setting it for a temperature I was sure it wouldnt be able to get down to, just to make sure it ran continuously to clear things out.

I also set up one of our big Patton fans, on high (which could lift Sally Field off the ground), and opened all the AC vents (we usually leave a few of them closed) to circulate air through the house.

Turns out I was wrong.

At 6:54 this morning, my AC unit shut off by itself for the first time since April. It was 86 degrees outside, and 56 degrees inside.

That ice dam must have been building for months, and because we were so used to the old AC units performance we didn't notice how poorly the new one was performing.

Now we just need to deal with the water damage... tiles aren't supposed to go "squish" when you step on them, remember?