Window AC converted to central. First 94F day of season #6 page 9

BTW, based on what's discussed earlier in this thread, I did a partial mod on my window AC for the bedroom, "sardine-can"ing the top open far enough to about halfway expose the squirrelcage fan's outer circumference to get greater airflow out of the unit.

I couldn't go all the way open yet, because the bar that helps secure it into the window presently goes thru the back half of that area. To fix it I'll have to remove the unit from the window, then take the bar off, drill new holes in the top panel further back, reattach the bar, then peel back the top the rest of the way to allow full airflow via the squirrelcage fan.

But it already makes a significant difference, especially to the freezing up of the indoor heat exchanger when the humidity goes way up (mostly at night). Now it only freezes about 1/3-1/2 way up before the cycle ends and it shuts down to let the ice melt and run off outside thru the tray.

Before that, it would freeze up the entire indoor exchanger, an no airflow at all would occur, and it would never shut off the compressor at all until the ice got thick enough to reach the in-airflow-path temperature sensor (quarter inch or so past the grille). Just wasting power at that point, and not cooling the room air.

amber
sounds like it is low on freon/puron. my old goodman would ice up whenever it got low. the coil should not get cold enough to make ice

Whenever I've had a low-coolant unit, it simply doesn't cool well enough (or at all). I haven't had one freeze up from that yet, no experience of it's possibility or not. I don't have a way to increase the coolant anyway, so cant' test the theory.


Besides, it always has frozen the water to the indoor exchanger, in humid weather, or any time humidity goes up enough, and the outdoor exchanger is cool enough. If it's over 100F outside it won't usually completely freeze up, but I'll often still see frost on the coils, if not the fins.

Right now it's humid enough that the towel I have tucked into the front of the exchanger tray and hanging down into a bucket has filled it over 1/4 of the way full, maybe a gallon and a half of water, since this time yesterday.

This one (and one other) even has a "dry" mode that's designed just to do that--it slows the airflow way way down and deliberately ices up the indoor exchanger, then shuts off everything after some period of time and lets the ice melt and the water run off, to try to dehumidify the air. I don't use this mode because it doesn't really cool the room itself enough to be worth the energy usage, and the other mode works too, just not as quickly.

All the window AC units I've ever had do--they just don't have enough airflow thru them to prevent that, AFAICT. Even the brand new ones (of which I've only had two, one just like the one I have now, and one much larger unit).

Over the years I've tried a few things, including adding a set of external fans (big 5" high-volume rack-server cooling fans) in the output duct to pull air thru much faster than usual, and pretty much anything that increases airflow sufficiently will stop or reduce the ice formation. Just that the extra fans also adds a lot of noise.

easy check is to compare watts to another one, or to the factory stated watts, which can vary quite a bit, but usually gets close after 15-30 minutes.
When my goodman was low, it took a lot less watts, but had to run a lot more, until it iced up, then i'd let it defrost, and run a lot more, so my bill was high and it was iced bad by mid-afternoon.
this is why ac guys put on a clamp on meter to check the watts, when they first arrive. they want to see a sign for low freon.
Was a good idea to increase air flow 8) The 1st ac step in the book is to raise fan speed. 8)
And it did help a lot, so your plan to open it up more sounds good to me. 8)

amber- i'm sure you have a good reason to NOT do this :lol:
But, i'd drop the ac down on blocks about 3 feet from the window, so the wall stops any noise, and run 2 ducts into the window. this way only 3-4" of view gets blocked, and 95% of the noise remains outside. This is your assignment for this winter, should you decide to upgrade.
And borrow a Kill-o-watt meter and check it. if it is leaking, next year it will draw less.

Well, I actually *want* the window blocked (the rest of it is filled with styrofoam sheets), as it's west-facing. I also have sunshades as an "awning" of sorts from below the fence top to the roof eaves, but anything that keeps the heat from getting into the room in the first place means less work for the A/C unit to do.

If I use ducts, I have to heavily insulate those, too, so heat doesn't leak into them and make even more work for the unit. Also have to make them leakproof to air at the joins. And I'd have to use ones large enough to block the window anyway, to keep the airflow high.

I had planned to do this sort of thing with the big unit I had before the fire (was stolen by the cleanup crew), but it's not worth the effort for the little one (at best, half the size of the big one).


Also, I actually like the noise, since generally I'm only using the unit at night when trying to sleep (I work during the day), and the dogs don't stay in my bedroom unless I'm there (or unless there's fireworks or storms or whatever, in which case Yogi often hides in there).




I *would* like to move the roof unit down to the ground to keep it out of the sun, and reduct it thru the wall rather than the roof, but that's not an option at all.

Best I've been able to do is cover the roof unit's exterior (except the exchanger/fan area) with layers of styrofoam, including the duct from ti's side down into the roof, and then also cover the ducts inside the attic the same way. This keeps as much heat from getting into the unit and thus the air, and so it does't have to work as hard. My brother keeps the circulation fan on all the time, so without the extra insulation, the air thru the ductwork heats up more and makes teh A/C come on much more often, and the farther rooms (like his) don't stay as cool. After I added the insulation to the roof unit, he actually had to turn the A/C up a couple degrees so it didn't chill his room down so much.

So, this is the 3rd time it hit 91F and my 3 ac's are not keeping up Can shut off zone 2, and zone 1 works great, but can't run all 3 at once without the ac room temp going up up up
Kitchen duct shows 74, return 84, so it is still cooling decent, so i think.
So i go into the loft, i've never gone up there on a hot day.never in 29 years, until now. 3:20 PM. the floor was 119F unit 3 exhaust 126F, input 104-119 Unit 2 only 120.
Gable fan now on medium is not keeping up Unit 1 is off and 2+3 are sucking up ALL the airflow. So i will have to up the fan to HIGH for warp drive :lol:
I feel like i just visited Las Vegas If i passed out up there i'd be dead in minutes. I don't know how those ac guys do it :|

Yeah; imagine what it's like here in Phoenix. :lol:

(right now it's still humid enough that I just emptied the bucket an hour ago, and it's an inch deep already).

just to recap why i didn't(yet) hook units 2+3 to the gable vent, and send the hot condenser air out the side of the house:
1. i was SURE 10k btu would be too small, no sense spending several hours hooking it up, when this is only a test. i was sure it needed 18k-24k btu, but i had 2, 5k ac's and cost was near zero to try them out (as i consider this to be a hobby)
2. it is a test, because i've learned that anytime i'm SURE, i could be wrong, and to my surprise 10k btu cools pretty good. When i buy a spare, it will probably be 12k-18k, not the 18-24 i thought.
3. splitting the vent into 2 zones will be easier to get right if i know the airflow of each zone. 8 vs 12 would be much different than 8 vs 24, for example.
4. my bench tests showed only a 7-8 degree rise thru the condenser. i was SURE my attic ridge vent would exhaust this heat. WRONG the rise is 20-25 degrees and the air is swirling around, not going up and out.
SO, this winter my plan is to hook up zone 2 to the gable vent. Until next summer, i'll use zone 1, a room that is plenty cool, even on those rare 90+ days. (i just shut off zone 2 around 3 PM and stay in zone 1)

so today i did an experiment. since it never really cooled off last night, 78 low, i turned on zone 2 at 5:35 am. ran it for 3 1/2 hours, and the ridge vent did exhaust the hot condenser air did not turn on the gable fan!
so here is my guess as to what goes right/wrong.
in the dark there is a good chimney effect, hot attic air rises, hits the 78-80 outside air, and goes right out. BUT in the heat of a hot sunny day, the entire roof gets so hot that it is just as hot on the roof/vent as INSIDE the attic so there is no chimney effect and the hot attic air is not drawn out so this is why i have to duct the hot condenser air to the gable vent, where the force of the ac fan will force it out. 8)
.
at the end of the test the kitchen dropped to 79 from 85, so 10k btu's does work 8)

Possible circulation "fix":

Add intake vents at the roof edges (under the eaves). Increases available uheated air to refill attic.

Or, reverse the gable fan airflow, to push air into the attic, so that it starts up an airflow up thru the roof vents (assuming you have fans flowing into the attic from all gable vents, and not just one).

Or move the gable fan to the roof vent, sucking air up and out, pulling it into the roof vent. (the most "natural" circulation path).

Add motor to roof vent, to spin it and create suction to start airflow. May not need to run past starting up the airflow (few minutes?).

amber- thanks for the ideas
I'm actually satisfied with the ac as it meets my needs. I'm done cooking in the kitchen by 2pm, so even when i upgrade i still intend to shut zone 2 off after 2pm.. Why run it when i'm not in there?
When i get bored, i'll hook up the 12" flex duct that was leftover. it only comes in 25' lengths, so i had to buy 25 when i only needed 12. So i'm not going to do anything fancy, i'll just finish the install next winter. zone 1 works great so a similar hook up is all it needs. Then if i have company i'll be able to run zone 2 steady all day,

Best operation to date! Made a wiper seal for the pocket door to the former living room, which is now a windows open florida room. Not easy to seal an interior pocket door, but i figured out how to do it, with some old stiff vinyl my neighbor was about to throw out. So it still slides, but has the vinyl 1/32" from the door so it doesn't stick and leaks very little. had a 1/4" gap before
Hottest day of this summer, 93F(feels like 100) Was breezy and that helps keep the attic less hot.
ran zone 2, 8 hours from 8am to 4pm and shut it off as clouds popped up with rain at 5pm, as frequently happens from the sea breeze. No complaints, house was comfy without using zone 1. Amazing that 10k btu can cool this good Might not bother to hook up the outside vent, will see how the rest of the summer goes. days will get shorter, and that will help too. Moral of the story, everyone should make sure their doors and windows seal tight! Easy door check is to put a sheet of paper across the door jam and close the door. then pull out the paper. if it is tight, seal is good. do this all around the door every year as weatherstrip is designed to fail so they can sell you more :lol:

merged zone 2 into zone 1 8) Re-connected the zone 2 main duct to zone 1 (had it blocked off because i couldn't imagine there would be enough btu's) adjusted vent so it blows directly on my lazy-boy chair, my favorite spot. This makes it feel so much cooler, i have to shut it off sometimes, a clue that there really is enough btu's. Now my favorite room has two ac systems, so i don't feel the need for a spare ac.
For the den i removed the vent and took out 4 slats (still has 11). Now the faint breeze can reach the desk/chair, and it feels cooler.
So with these final changes, i hereby declare the ac system FINISHED and 8)
10,000 btu cools 700 sq feet(if i need ac at night i can just use the 8k for BR).
(old was way oversize, 35000 for 1100sf)

zone 2 is nearly silent, and that makes me very happy. (zone 1 is more like old goodman, 47db) not bad at all, but not silent like zone 2.
Thanks for reading! I don't plan on buying an old school central ever again

So with a near 100% humidity and 80F at 6am, there is no point to opening the windows, as i usually do in the 74-78 range. It would just feel like a sauna in here if i do (like the bathroom).
The trick to cooling with 10,000 btu is to turn on the ac early, this time at 6 am, as the kitchen was 85, as it never cooled off. But humidity was low inside. So now 11:45am it is comfy 79.5 in the kitchen and 50% humidity, 80.6 in the BR (unit 1 is off), and the den is 82F.
it is 89F outside.


.
EDIT: took a peak at the meter, DOWN 5.9% from last year 8)
EDIT 2: got bill, down 7%

Had zone 2 off for an hour while i took a shower.
then ON, but weak airflow then a smell. OFF!
Went up there to check for a fire, no fire, and little if any smell. Too hot to work on it today. Will check tomorrow before the sun comes up.
Wild guess, the capacitor in the 16 yr old haier went bad and the fan motor didn't start, and overheated. That is 1 part i've seen go bad in other ac's.
Turned on zone 1, so i'm cool 8)
.
UPDATE: zone 2 is back on and working good! A failed hot start is on the list of possible ac complaints.
Ran it for 6 hours, nice and cool 8) Off.
Now in zone 1.
Glad it was not damaged

found this review of a 10k ac on the GE site:
"My brother bought one of these, first really hot day it quit and set an e8 code. Looked up that code and it said overloaded "don't operate in high humidity areas above 90 degrees ambient temperature". Really? Why do you sell this piece of junk in Texas?"

:lol:
it has been there for a month, and GE has no comment.
I can't make this stuff up! I probably have the same electronic control in my 8k.
If it ever acts up like that, i'd just bypass it with an on/off relay.

I've seen ads for variable BTU AC, both central and mini-split. At first i did not like the fact that they run all the time (my old blower alone was 500-550w, the new type is DC and much lower watts). Sure they slow down, but i thought ac should shut off when the desired temp is reached.
My new system turned out, just by chance, not my plan, to be similar, in that i select 8k, 10k, or 18k btu.
And i've learned the benefit of their idea. The gentle breeze of continuous 10k operation allows a just as comfy, but higher temp. When i use just 10k steady it feels cool, but, if i shut it off it feels stuffy and too warm. And my new fans are low power, around 20-25 watts each. So I give the idea 2 thumbs up, now that i see how good it works.

The test works so well, for a while there i forgot that units 2+3 are temporary, for testing only. (one is 16 yrs old, and the ducting is very temporary)
So i've decided to make a permanent install this winter with a new 12,000 btu Artic King on sale $199 I could pick it up at the store, but for $30 i'm having it shipped UPS. Total w/tax is $243. Found a similar model that had 4.4 stars out of 5, and i've read that artic king is imported by LG.
Will have 3 power levels; 8k btu, 12k btu and 20k btu 8)
.
And the two 5k's will be spares in case my 8k BR ac ever dies, either one could easily replace the 8k to cool an 11x14 room. And they are already modified for quick hook up.

Just came in! 8) 12,000 BTU 115v
packed in huge box, 78 # (ac about 65#)
made in china 6-18, so not an old model, 21.5" deep
tag says 9.5a 115v Fan 90w on hgh (3 speeds)
Looks nice, will not turn it on until later, in case it was upside down in truck.
Kudos to BrandsMart for a low price 199, great packing, and fast shipment.
https://www.brandsmartusa.com/arctic+king/219434/12+000+btu+air+conditioner.htm?utm_source=trx&utm_medium=email&utm_campaign=shipment
total w/tax and FedEx $243
UPDATE:
Sounds great, best sounding ac. Now i see how Amberwolf likes the sound of his ac- it sounds pleasant, like this one.
Artic king is a good name, i measured temps in the 20'sF before it stabilized around 40F. maintained steady 40 on low med hi- i don't know how a cheap ac can do this 8)

Matt Gruber said:

Just came in! 8) 12,000 BTU 115v
packed in huge box, 78 # (ac about 65#)
made in china 6-18, so not an old model, 21.5" deep
tag says 9.5a 115v Fan 90w on hgh (3 speeds)
Looks nice, will not turn it on until later, in case it was upside down in truck.
Kudos to BrandsMart for a low price 199, great packing, and fast shipment.
https://www.brandsmartusa.com/arctic+king/219434/12+000+btu+air+conditioner.htm?utm_source=trx&utm_medium=email&utm_campaign=shipment
total w/tax and FedEx $243
UPDATE:
Sounds great, best sounding ac. Now i see how Amberwolf likes the sound of his ac- it sounds pleasant, like this one.
Artic king is a good name, i measured temps in the 20'sF before it stabilized around 40F. maintained steady 40 on low med hi- i don't know how a cheap ac can do this 8)

Click to expand...

Sheesh, even if the Arctic King lasts only 2 cooling seasons you're still ahead. It's nice that it has a 5 star rating too. 8)

Hi ed!
Yes. Part of the reason i'm not trying to squeeze more years out of my test units #2+3, is that i'm only out $95, and in just 1 season i got my moneys worth. (had the 16yr old 5k, got a new 5k $85+ drain pan)
Compare that to my Goodman:
10 years for $3600 is $360 per year. $95 is pocket change by comparison.
It had a heat pump too, so maybe i saved $40-100/yr on heat cost. So net cost 260-320/year(plus electric).
While the Goodman had a nice sounding 10 yr warranty, it turned out to be a scam. They would not give me the coil to fix it myself. Must be fixed by an authorized goodman dealer, and they charge like $800 to replace the "free" coil. So now they lost a customer for ever
.
This is going to take a lot less time to convert, as now i have a much easier hook up. Already have the new one apart, and i know just what to do. And no worries about the idea working

Was riding my bike on trash day and picked up an empty reel made in 1989 when they used 1/2" plywood ends. tag said 1000' 14awg. I'm making an adapter to connect the 6x9" top supply (moved from the front) to the Home Depot 12" flex duct. I have to cut it down from 16" to 12", but having a perfect circle makes it easy.
Would have been nice to find a 12" reel But i've never seen any wood reels around here, so this is good for free. And there are 2 ends, as i will stack the 2 for use with a band clamp.
I'm glad i have something to do inside, as "the dog days of summer" around here, last until Oct 15th, 5 months of 90% humidity gets tiring.
I'd say that moving the cold supply to the top is key to making the conversion a success. To connect to the front, well, i think anyone would be discouraged with the time it would take to make such a connection, and it could easily leak air, and have poor flow. The top supply gives loads of room for the other two, 12" flex ducts.(3 total)
.
I'm thinking of putting the 16 yr old 5k ac to work in my workshop for next summer. Similar to the house, the ac would be in the garage, and i'd run an 8" flex duct to right above the work bench. the noise stays behind a wall 8) and the ac never sees rain.
On a really hot day, i'd open 1 bay door, so the ac stays cool 8)

A little off the thread tangent, but relevant. I built the house in 1987, and I personally installed a 5 ton R22 system. I bought a 30lb bottle of R22 just to have it back then... cost about 100 bucks.

Fast forward to last year. Old system was costing me a total of 500 bucks a month to run during june july august. After 30 years the compressor finally seized up, but didn't burn up. Thats important as there was 10+lbs of usable R22 in that system.

I sold the new tank of R22 for a little under $600 and the recovered 10 lbs for another hundie. Scrapping out the copper and aluminum on the old system netted $196 bucks. So scrap income and R22 sale on the old system was $900.

New system was gotten "real" wholesale. 5 ton national name brand condenser (NOT Goodman, much better) $890, ADP 5 ton evaporator in insulated housing around $300. Puron system. Total new system parts around $1300. Net out of pocket $400

I installed it all myself, had my refrigeration buddy come by to vacuum lines and fill lines/evap with puron. Cost... about 2 hours on the Bridgeport making a part for him.

New system running around $260 a month in electricity. It's been on 24/7 all summer. Same savings last summer. $240 a month savings. ROI on new system less than two months!

Moral... it pays to have friends. New stuff uses a lot less electricity. Home is much more comfortable. The markup on A/C hardware is INCREDIBLE! Better yet, get your refrigeration license. Take a course at the local college, pass the exam. Now your legal. Pays off quick. Great sideline if I was younger.

Hi bigmoose,
Great story; thanks for posting 8)