The
DRSNews
August 2003
In this issue:
1) ‘The Power of Eights’ – Brightening Dull Digital Displays
2) Fast and Simple Window A/C System Diagnosis
3) Your Refrigerator And ‘HHH’ Weather – Quick Tips
1) Every once in a while we see a fluorescent digital display that’s
grown really dim and hard to see, most often in a microwave oven controller. In many cases it’s just those digits, or parts of them, on
the left side. And
there’s a quick fix that you might find useful.
Displays often need to be disassembled and cleaned to correct this – our homebrew window cleaner works well for the purpose – but it’s not an easy job. But if yours isn’t as bright as it used to be (be nice –
I’m gettin’ old & sensitive!), especially
those seldom used segments of digits on the left, try this.
Simply enter ‘8888’ (assuming a 4-digit display) and let it sit
that
way for the better part of a day. This will ‘burn off’ impurities that have accumulated on the little-used segments/digits, and the results can be dramatic.
Not something you’ll see often, but worth a try. Note this doesn’t apply to LCD displays, but only fluorescents, whose digits actually glow.
2) Back in March we talked about easy diagnosis of home refrigeration systems using the frost pattern on the evaporator coil.
We warned against
allowing anyone to poke a hole in the system to attach gauges, etc, to ‘check the system’, because it’s simply unnecessary.
This also applies to window air conditioning units, with only a slight difference. If you think yours may have a system problem (leak or restriction, etc), just run it 15-20 minutes and inspect the evaporator (cold) coil. Instead of an even pattern of frost, as in refrigerators, you’re hoping to see a nice, even coating of water droplets over the entire coil. This can be hard to see on some units and at some humidity levels. But it’s a lot easier to check if you can gain access to the copper return bends at the coil ends, where the moisture shows up much better than in the coil’s fins.
If the condensation pattern’s covering the entire coil, and even the larger suction line headed back to the compressor, breathe easier – the expensive stuff’s OK!
If there’s only a partial condensation coating, or part of the coil’s frosted and the rest dry - ouch! You have a system problem. I’d still disassemble and double-check that the condenser isn’t clogged with dirt, but the above usually tells us it’s gonna be expensive!
This time of year many of the complaints we get on the smaller units come from sizing errors, so I thought it might be a good idea to reprint our handy-dandy ‘rule of thumb’ sizing guide:
Sq
Ft
Approx BTU's needed
100
3500-4500
200
5000-5500
300
6500-7000
400
7500-8000
500
8500-9500
600
9500-10.5k
700
11k-12k
800
12k-13k
900
13k-14k
1000
14k-15k
1500
19k-21k
1800
22k-24k
2000
23k-25.5k
|
(These
figures assume an occupied space above the ceiling; add about
½ size if the ceiling is insulated under an attic, and add a
full size if the ceiling is
non-insulated. Also, add at least one size if the cooled area
includes a kitchen)
|
3) Here are a couple of quick tips to help keep your refrigerator
purring happily along in August’s heat, haze, and humidity:
Keeping the condenser clean is probably the most life prolonging kindness you can give your refrigerator, and the trusty
wet-vac and a long brush make it quick and painless. See the 5/02 DRSNews for more.
If you’ve noticed the fan motor in your freezer section running noisier than usual, or if it’s been making any intermittent
‘squealing’ noises that you’ve been blaming on the cat, now’s the time to replace it (the motor, not the cat... well, yeah, maybe the cat too… <grin>) Fan motor bearings that are failing or
badly worn will often ‘rattle’ and slow the fan down, and when they become ‘terminal’, they’ll often start to squeal – not what
you want to hear in July or August.
In the most common refrigerators that one little fan motor is responsible for circulating air through both the refrigerator and freezer compartments. And if it’s running at all slow, as they say
here on Hatch Hill when the dog starts to ‘bear-bark’ in the wee hours, ‘better git up an’ do somethin’ ‘bout that ‘fore it gets ugly.’
And it’s surprising how much difference just cleaning those tiny fan blades can make in airflow. It’s noticeable immediately if the blade was very dirty. It’s amazing how filthy they can get
while running inside a clean freezer!
Well, that’s about it for this issue.
Thanks for allowing me into your inbox again this month.
I hope you enjoy reading this little project half as much as I enjoy
writing it for you. What
great friends we’re making through this great medium! Thanks for all your encouragement, guys! We really appreciate you!
May the Lord richly bless you & yours, and may He continue to have mercy on America.
Warmly,
Dave
Harnish
www.DavesRepair.com
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‘Blessed is the man unto whom the Lord
imputeth not iniquity, and in whose spirit
there is no guile.’ - Psa. 32:2
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