BajaNomad - Help needed!!!

Help needed!!!

JZ - 8-8-2006 at 05:55 PM

My power bills are out of control here in Mexico! I think most of it is due to the AC's. Any heating and cooling experts out there?

The house is pretty big (3,100 sq foot) and has high ceilings. It has two AC's. One for the main house and 1 for the bedrooms. I have been trying to run them at anywhere from 78-80 degrees, but the bills are still really high.

I'm thinking about getting a timer control to make the bedroom temps cool at night (78-79), but maybe 82 or so during the day. And the opposite for the main part of the house (80 daytime, 82 night time).

I don't know much about AC units, so I need to ramp up my knowledge. I had an AC guy over today. We going to try and take some airflow from the bathrooms and re-direct it to the bedrooms. I noticed the bathrooms were cooler than the bedrooms.

He said my units are 12 Seer (?). I'm wondering if replacing them with more efficient units would make a big difference in power consumption.

Any thoughts/suggestions?

comitan - 8-8-2006 at 06:44 PM

JZ

It looks like you have efficient units, you have a big house, I think the only way would be to lower the settings. Just use fans at night, you will just have to get used to the warmer climate if you want to lower your electric bills.

Roberto - 8-8-2006 at 07:43 PM

Sorry, no help from me. :lol:

But, could you give an idea of how much "out of control" is?

comitan - 8-8-2006 at 07:49 PM

JZ

SEER of 12 is good but they do go as high as 17 being the higher the number the more efficient.

JZ - 8-8-2006 at 07:56 PM

Quote:

Originally posted by Roberto
Sorry, no help from me. :lol:

But, could you give an idea of how much "out of control" is?

$2,000 for two months!!!!

jerry - 8-8-2006 at 07:57 PM

heck just get a window ac for the bedroom run it only at night or when you get a hot flash and say the hell with the rest

bajabound2005 - 8-8-2006 at 08:05 PM

First and foremost, have your meter(s) checked. Secondly, add ceiling fans! 3100 sq ft is a lot to be cooling. Only cool what you need to, add additional room (window) a/c as needed to cool only th eroom you need to cool. And lastly, where are you?

JZ - 8-8-2006 at 08:08 PM

Quote:

Originally posted by bajabound2005
First and foremost, have your meter(s) checked. Secondly, add ceiling fans! 3100 sq ft is a lot to be cooling. Only cool what you need to, add additional room (window) a/c as needed to cool only th eroom you need to cool. And lastly, where are you?

How can I have the meter checked? San Carlos, Sonora.

JZ - 8-8-2006 at 08:36 PM

Quote:

Originally posted by comitan
SEER of 12 is good but they do go as high as 17 being the higher the number the more efficient.

I heard they go up to 19. The AC dude was suggesting to replace mine with a Carrier 5 ton 14.6 SEER.

Well, that explains everything.

Dave - 8-8-2006 at 08:40 PM

Quote:

Originally posted by JZ
San Carlos, Sonora.

Seriously, 3100 sq ft-in the Sonoran desert-in the summer...What did you expect?

What is CFE charging per kwh? In Mexico, the more you use the more they charge.

JZ - 8-8-2006 at 08:48 PM

Guess I was't thinking Dave. Yes, I understand there is a tiered billing system here. I'm going to start tracking my usage if I can figure out how to read the meter.

My neighbor's house is probably 2,300, he has one AC, but his bill is more than half mine and he runs it on 80 all the time. Mine only runs about 1/2 to 2/3's of a month. I think his is more energy efficient then mine.

[Edited on 8-9-2006 by JZ]

Dave - 8-8-2006 at 09:00 PM

Used to be that you could get 2nd service with an additional meter and split your use cost. But the CFE, at least here in Rosarito, got smart and stopped that. Now, unless the billing is under a different name, they won't install additional service.

My advice is to add ceiling fans and only cool the bedrooms at night.

tim40 - 8-8-2006 at 09:22 PM

Is it possible that the meter is wayyyyy off? 1k/month is high by any standard and 12 seer is not exactly a power hog...unless it is having a compressor issue. At that rate...you would be better off to move into a hotel room during the warmest days....yikes

JZ - 8-8-2006 at 09:28 PM

One more thing I forgot to add. The ceilings in the bedrooms are 11 foot and 16' in the main part of the house. Yes, another mistake!

Diver - 8-8-2006 at 09:43 PM

So, lower the ceilings, add insulation, get "warm-window" blinds to cover the glass, paint the roof white, get more efficient cooling units, seal all draft openings, turn off the bedrooms in the daytime, turn off the living rooms at night, maybe add a solar cooler..........

Now wait a minute !!
Who wanted a comfortable 3000+ square feet in the desert, anyway ??
You could always move to Alaska :lol:

.
Seriously though, seal all draft leaks, get GOOD insulated window coverings, see if you can add ceiling/roof insulation and make sure the roof color is light. You may be able to add some rigid foam insulation to the ceiling and then re-stucco over it without much trouble. Also, check the wire and breaker sizes to the AC units to make sure they are getting enough juice to run efficiently.
.

Roberto - 8-8-2006 at 10:46 PM

Quote:

Originally posted by JZ
$2,000 for two months!!!!

Wow!

Here is what I would look into:

1. Ceiling fans MAY help. The hot air will get trapped at the top, and raise (upstairs?) sleeping quarter temps.
2. 3M has a reflective film that goes on the windows that really helps in keeping the temps of the glass down.

bajabound2005 - 8-9-2006 at 06:40 AM

Quote:

Originally posted by JZ
My neighbor's house is probably 2,300, he has one AC, but his bill is more than half mine and he runs it on 80 all the time. Mine only runs about 1/2 to 2/3's of a month. [Edited on 8-9-2006 by JZ]

Maybe he's running off your meter!

dono - 8-9-2006 at 07:29 AM

We lived in a 3500 sq ft home in Los Barriles for 3 years and our biggest electric bill was about $200 a month and thats keeping the temp around 78* one of the long term benefits of having an insulated home.

Oso - 8-9-2006 at 08:32 AM

Quote:

Originally posted by Roberto

Quote:

2. 3M has a reflective film that goes on the windows that really helps in keeping the temps of the glass down.

I looked into this when building here (2 miles from Sonora border) and decided against it based on info that may or may not be technically correct. I have low-E thermopane windows on the South and West sides, only one small window on the East. I was informed that installing the reflective film on thermopane windows would heat the space between the panes to the point that it could blow the seals. (I've not heard of installing the film on the outside of the window). Of course if it's an older house with single pane windows, the film sounds like a good idea. In this area, a lot of people use a type of window screen that reflects sunlight and has a shading effect. I planted bouganvillea to shade the West windows.

BTW, we hit 116 a week ago. My wife is home all the time so we leave the thermostat around 75. I could probably save a few bucks setting it at 78, but the divorce would probably be more expensive in the long run. So far, I haven't had an APS bill over $200, even in July. But then we have a bit less than 1,200 SF, I did all my own insulation and have a 13.5 SEER heatpump.

JZ - 8-9-2006 at 08:37 AM

Are you in the US or MX.

oxxo - 8-9-2006 at 09:09 AM

Quote:

Originally posted by OsoI was informed that installing the reflective film on thermopane windows would heat the space between the panes to the point that it could blow the seals. (I've not heard of installing the film on the outside of the window). Of course if it's an older house with single pane windows, the film sounds like a good idea.

Quote:

Do NOT install reflective film anywhere on low-E thermopane windows either inside or outside. Single pane windws is okay but still not as efficient as using thermopane windows.

Roberto - 8-9-2006 at 09:33 AM

Hmmmm. I have had reflective film on my double-paned windows for close to ten years.

Oso - 8-9-2006 at 05:26 PM

Quote:

Originally posted by Roberto
Hmmmm. I have had reflective film on my double-paned windows for close to ten years.

In that intolerably oppressive San Diego heat? It's a wonder the glass hasn't melted! :lol:

Oso - 8-9-2006 at 05:28 PM

Quote:

Originally posted by JZ
Are you in the US or MX.

If that was for me, I'm in the U.S. (barely), due South of Mexico and California.

jimgrms - 8-9-2006 at 07:48 PM

if ou have a attic put in exaust fans the vane type that need no power cools your attic and helps some with house

oxxo - 8-9-2006 at 08:13 PM

Quote:

Originally posted by JZ
One more thing I forgot to add. The ceilings in the bedrooms are 11 foot and 16' in the main part of the house. Yes, another mistake!

Tall ceilings should not be that much of a factor when cooling a house. They are are factor when trying to heat a house during the winter months. You know warm air rises, cool air falls.

If you install ceiling fans in a tall ceiling then you need to add extentions to get them down to the right height. There is a formula that you can use available on a ceiling fan website.

jerry - 8-9-2006 at 08:33 PM

right cold falls. heat rises .so in a room with tall celings a celin fan is just going to mix the air unless your beds on the celing its counter productive leave you bed on the floor and vent the top slightly knock a hole in the wall stick a small ac in the hole and injoy your sleep tomorrows another day and you will think clearer havin a good night sleep besides when im sleeping i dont think of how big my house is and anyone who complanes well chip in for the ac??

Wally - 8-14-2006 at 08:39 PM

An electric bill that big is certainly an eye opener. I offer up a recent experience that we had for consideration. Like you, we got hit with a big bill, $900 for 2 months. Based on the size of our house, 2,000 sq ft, and the fact that we hardly ever run AC (and only in 1 bedroom for sleeping), this didn?t make sense. Rather than looking at the actual charge, I focused on the usage which was 2,800 kWh for the period. Way too high even if we ran everything we had all of the time. After unplugging or shutting off everything we own I checked the meter?still spinning at a pretty good clip. Checked and re-checked that everything was off. No good, something was still drawing electricity. I then went through the process of shutting off one circuit breaker at a time on the main box and checking the meter each time. Finally, the last breaker (isn?t that always the case) stopped the meter from showing a draw. After spending 3 hours of tracing every possible problem, I discovered that during the installation of a ceiling fan, a hot lead was inadvertently connected directly to ground. The switch box had an extra hot lead (blue) that changed color (to green) before it made the ceiling box. The installer (me) figured that the green wire was ground. This only mattered though when that particular switch was on. When we bought the house we couldn?t figure out what the switch was for because when you flipped it on and off nothing happened. At some point we or a guest staying in that room flipped it on. With the switch on, electricity was just being pumped directly to ground. Dumb? Yes. We did talk to an electrician and he was convinced that it was a feed line that had become un-shielded and that he was going to have to dig up the line for inspection. According to him, he sees this all the time. Thankfully it didn?t come to that. Our housekeeper had her 2 cents to add, in that, CFE is corrupt and that they randomly ?fix? the meters to show higher than actual usage. Don?t know about that as she?s a little paranoid to begin with.
I guess my suggestion is that you may want to check to make sure you don?t have a problem, and that the size of your bill is a result of actual consumption, before spending money on new appliances or some other solution. You can get a pretty good idea what your usage should by using any one of a number of kWh calculators on the web.
One last point. We have 2 electric meters on our property in San Jose, 1 for the house and the other for the casita. Going with the housekeeper?s conspiracy theory, we had CFE send someone out to verify the meters were measuring correctly. We understood that there is a sliding rate scale used by the CFE (the more you use the higher per unit rate you pay). His suggestion was to balance out the usage between the 2 meters. Duh, why didn?t I think of that?
We didn?t, and still don?t, know at what point the usage kicks you to the higher rates, but an analysis of both August bills provides some color. The usage on the casita was a total of 368 kWh, of which 300 kWh was billed at .527 per unit and 68 kWh was billed at .628 per unit. The house usage was 2,480 kWh, which was all billed at 2.605 per unit with a flat charge of 113.72 pesos tacked on.
I?m going to give it a month to get a better read on what our actual usage is (sans electrocuting the grass) and will then see what can be done to lower the per unit rates, i.e. wiring the house AC unit and water heater to the casita thus getting a better balance of usage between the 2 meters.
Anyway, good luck.

JZ - 8-14-2006 at 09:13 PM

Thanks for taking the time for the detailed write up Wally. After getting some large bills at the end of last summer I was convinced that we had a wiring problem like the one you suggested. I had it checked several times for some erroreous draw. After that bill summer was over, and my next bill was very reasonable.

So, I had some blinds installed and started running the AC less at the begging of this summer. I was very surprised to say the least with the bill. Now I am monitoring power usage constantly.

Here is the tiered rate plan in Sonora:

Basico 0-150kw .603

Intermdio 151-400kw .995

Excedente 401kw - ? 2.101

[Edited on 8-15-2006 by JZ]