Help AC can't keep up with the heat.

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Lithium381

Lifer
May 12, 2001
12,458
2
0
At my house here in Texas I keep my central air turned to ~83 when we're here and have a portable air conditioner in the bedroom set to ~70 to help get us to sleep though it has been known to wander into other rooms in the house...
 
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Mungla

Senior member
Dec 23, 2000
843
0
71
In Central Oklahoma - we installed a Waterfurnace 5-series geothermal HVAC unit when we built our new house. So far, I'm very impressed. Super low electricity usage and nice and comfy inside no matter what the temperature is outside.
 

skyking

Lifer
Nov 21, 2001
22,215
5,075
146
In Central Oklahoma - we installed a Waterfurnace 5-series geothermal HVAC unit when we built our new house. So far, I'm very impressed. Super low electricity usage and nice and comfy inside no matter what the temperature is outside.
Did you do vertical wells, trenches, or a big dig with the coils?
We did the big dig for my brother's 3 ton setup, a 30x60x6 hole.
 

Mungla

Senior member
Dec 23, 2000
843
0
71
Did you do vertical wells, trenches, or a big dig with the coils?
We did the big dig for my brother's 3 ton setup, a 30x60x6 hole.

Due to the temperature and drought extremes here, the experts say that vertical wells are the only reliable method. Our unit is 3.5 tons and they dug 3 vertical wells 205' deep each. The header setup that connects the wells is 6' deep in the ground in our front yard. Now that we have leveled out the yard, planted sod, etc., you would never know the wells are there. With the 30% credit from the IRS and $800/ton rebate from our local utility, the Geo ended up costing $14,000 out of pocket.. Versus $9,000 for what a traditionl dual-fuel 13 SEER unit would have cost. For $5,000 difference, it was a no brainer.
 

BUTCH1

Lifer
Jul 15, 2000
20,433
1,769
126
Actually the plan, I have 220V on that outside wall. The previous homeowner supplemented that room with a very small inefficient 120V unit that just ran maxed out until it burned out.

Yea, with 120v IIRC the max BTU is around 10-11K and then you can't run anything else on that circuit, much better to have 220V, more options and better efficiency.
 

Red Squirrel

No Lifer
May 24, 2003
67,898
12,365
126
www.anyf.ca
Yea, with 120v IIRC the max BTU is around 10-11K and then you can't run anything else on that circuit, much better to have 220V, more options and better efficiency.

My 12k btu unit uses like 14.3 amps, so yeah pretty much the limit for 120v 15a. I ended up running a dedicated 20 amp circuit for mine. Actually two, I split the socket so that top and bottom are a different circuit. Not really a MWBC since I could not find 12/3 wire at the time so just ran two 12/2's. That way it gives me extra power to use that outlet for something else too.
 

BurnItDwn

Lifer
Oct 10, 1999
26,126
1,603
126
My AC is a 3 ton unit and has the same issues.
In my case it's because it's a very old central AC. (15+ years)

The coils on my outside unit are corroded. I cleaned it the best I could with the hose. And that made it a bit better. (though HVAC guy says it needs to be replaced)

The filter changes do help if you do it at least at the beginning of the cooling season and beginning of warming season (though HVAC guy says to change it every month.)

If you have a basement, make sure any/all vents in the basement are closed to direct the cool air to the house.
 

yottabit

Golden Member
Jun 5, 2008
1,375
240
116
Surprised no one has mentioned giving up on cooling the entire house and trying to cool only certain zones

For instance close off unused bedroom/bathroom doors, even put a little seal on the bottom of them.

Works better for window units I guess, but even with a central AC you can probably zone off some portions of the house that don't need to be cooled. Closing or blocking off AC vents even to make sure more cold air goes elsewhere.
 

skyking

Lifer
Nov 21, 2001
22,215
5,075
146
Surprised no one has mentioned giving up on cooling the entire house and trying to cool only certain zones

For instance close off unused bedroom/bathroom doors, even put a little seal on the bottom of them.

Works better for window units I guess, but even with a central AC you can probably zone off some portions of the house that don't need to be cooled. Closing or blocking off AC vents even to make sure more cold air goes elsewhere.
+1 for that.
 

BoomerD

No Lifer
Feb 26, 2006
63,353
11,725
136
I remember having AC...

Another hot one here in Western Warshington...supposed to break records...and me without AC.
 

RagingBITCH

Lifer
Sep 27, 2003
17,619
2
76
Surprised no one has mentioned giving up on cooling the entire house and trying to cool only certain zones

For instance close off unused bedroom/bathroom doors, even put a little seal on the bottom of them.

Works better for window units I guess, but even with a central AC you can probably zone off some portions of the house that don't need to be cooled. Closing or blocking off AC vents even to make sure more cold air goes elsewhere.

That throws your system out of balance. There should be balanced air into/out of the system. Air being sucked in registers should be approx the same as what comes out. Closing a door and/or vents throws it all into wack.
 

Red Squirrel

No Lifer
May 24, 2003
67,898
12,365
126
www.anyf.ca
That throws your system out of balance. There should be balanced air into/out of the system. Air being sucked in registers should be approx the same as what comes out. Closing a door and/or vents throws it all into wack.

A few vents should be ok. You can also block some returns as needed to help control air flow. Be careful though as you don't want to limit the air flow TOO much or the motor will spin too fast and it's not good for it.

I don't have central air, only a portable unit in my office, so sometimes what I do is aim it to the return in the hall and put papers on the return that's in the living room, with the blower turned on. Forces the cool air from the AC unit to go in that return as it will be sucking more air. You can play around with this a bit.

Another idea is to have a return right in the basement that's big enough for the whole system, with a cover. In summer remove the cover and then cover the upstairs returns. It will suck cool basement air upstairs. If you get a full week of heat wave this wont really work anymore though but it does help a bit.
 
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Murloc

Diamond Member
Jun 24, 2008
5,382
65
91
My employer rented me the equipment and I did all the excavation and restoration at my brother's job. It is dry there also, so I graded off the pit at 3' deep and put in a drainfield system. I ran all the yard drains and downspouts into this system to keep the soil around the coils moist.
http://s810.photobucket.com/user/skyking60/library/geothermal?sort=9&page=1
interesting, I never realized there were air conditioners of that kind for private homes, it must get really hot.
All I've ever seen is wall/window units.
 

skyking

Lifer
Nov 21, 2001
22,215
5,075
146
It is not about how hot, it is the efficiency.
Today it is 102 there. A standard heat pump is trying to put heat into 102 degree air.
The soil around those coils is about 60 degrees, much easier to put the heat into that. Same thing happens in winter, only the soil gets warmer and warmer in summer due to airconditioning heat. In the fall it is like free heat.
 

Josh123

Diamond Member
Aug 4, 2002
3,034
2
76
Our insulation in our house blows donkey balls. We had some guys come in and blow some more into our crawl space but it's still hot as hell and the AC is constantly running. We don't have any shade trees to help so our house gets direct sunlight all day.

I think the main things that would help our situation is having a big shade tree and install new windows throughout the house. I don't see either of these two improvements happening
 

jagec

Lifer
Apr 30, 2004
24,442
6
81
It is not about how hot, it is the efficiency.
Today it is 102 there. A standard heat pump is trying to put heat into 102 degree air.
The soil around those coils is about 60 degrees, much easier to put the heat into that. Same thing happens in winter, only the soil gets warmer and warmer in summer due to airconditioning heat. In the fall it is like free heat.

I always did like ground-source as an idea, and if I had the chance to put in the pipes myself (instead of having to pay someone $Texas to do it for me) I would do it in a heartbeat.
 

PottedMeat

Lifer
Apr 17, 2002
12,365
475
126
Our insulation in our house blows donkey balls. We had some guys come in and blow some more into our crawl space but it's still hot as hell and the AC is constantly running. We don't have any shade trees to help so our house gets direct sunlight all day.

I think the main things that would help our situation is having a big shade tree and install new windows throughout the house. I don't see either of these two improvements happening

stapling in radiant barrier helps. make sure your soffit vents are clear. check that you can see daylight from the attic, sometimes builders will stuff fiberglass batting in making the soffits useless. or the batts were stuffed in first, soffits cut, but nobody removed the fiberglass.
 

IGBT

Lifer
Jul 16, 2001
17,956
137
106
your house is a solar mass. it's a giant heat sink. Find a way to reflect the heat then your hvac should work.
 

Anubis

No Lifer
Aug 31, 2001
78,716
417
126
tbqhwy.com
OP, I have the same problem here. In my case, the AC condensor is too small and my options are limited because it's a rental.

Ended up getting a portable AC unit - works very nicely in tandem with the central AC to get the temp down to 75.
The bonus is that I can set the central AC higher (with the portable AC off) when I'm at work to save energy, since it now
doesn't take bloody ages to cool down in the evenings.



:thumbsup: Withing Temptation rocks
 

velillen

Platinum Member
Jul 12, 2006
2,120
1
81
I remember having AC...

Another hot one here in Western Warshington...supposed to break records...and me without AC.

Least ours only lasts a few days generally Though i do feel a sick day coming tomorrow to avoid some of the heat. I was lucky and got an AC unit on sale a couple weeks ago. It doesnt work that great but keeps my bedroom ~10 degrees cooler than the rest of the house. And it sits right next to my bed so the bed is even cooler than that. Works good enough for the couple days a year itll get used.
 

BoomerD

No Lifer
Feb 26, 2006
63,353
11,725
136
Least ours only lasts a few days generally Though i do feel a sick day coming tomorrow to avoid some of the heat. I was lucky and got an AC unit on sale a couple weeks ago. It doesnt work that great but keeps my bedroom ~10 degrees cooler than the rest of the house. And it sits right next to my bed so the bed is even cooler than that. Works good enough for the couple days a year itll get used.

I said "fuck this" today...we drove up to Mt. Rainier for the day. Nature's Air Conditioning was working just fine...about 70 at the top of Chinook Pass. Still plenty of snow in the high country.

 
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