Paging SuperGreg
 

Mr. SG! I have a question for ya, because I know you have already figured this out (other people chime in too!)

What is the best thing to do with A/C in the summer? Leave it on during the day to keep the house cool, or let it run 2 hours before you come home?

I figure if you leave it on all day it cycles on and off all day. The other choice is to turn it on a few hours before you get home and it will stay on pretty much for the entire 2 hours.

What do folks in AZ do that work during the day with no one home?

My thoughts on the matter..

I have a dog.. So here in LA when we get to that time of year when A/C is necessary, I tend to set it to auto at about 75 degrees. This keeps the a/c from having to run all day long and also prevents the house from getting toooo hot for the pooch to stay comfortable.
When I get home, I knock it down to 72...

B

A/C?! We have a minimal 4 zone, 2 compressor set up here on the mtn. Figurued it was cheap to put in when we built.
We had it on about 10 times per year for the past 3 "summers"...not yet, so far this year.

Hey Chris, this can be a very subjective topic for sure. My recommendations are suited more for extended high temp weather, but maybe you can glean something from them.

#1 Buy a 7 day programmable digital thermostat (Honeywell).
The temps can be set at 4 different levels during the day (wake,sleep,leave,return). Best place to buy is eBaY. I have two A/C's (Dual Zone). First one I bought at Home Depot for like $109.00. Next one I bought through eBaY for $52.00. Lesson learned. Here is a pic of their top of the line. It's a "Vision Pro" touch screen. There are many alternatives. PM me for other recommendations.
http://members.roadfly.com/tomatodude/visionpro.jpg
#2 During the summer, set your thermostat between 78-80 degrees when you are home, and 85 degrees or higher when you are away. For every degree you set your thermostat above 80 degrees, you can save approximately 2-3% on cooling costs.
You can set these new programmable thermostats to have your place already cooled down by the time you return home.
#3 Replace your disposable or clean your permanent air filters at least once a month.

Hope this helps,

Greg

this is a great topic. I am wondering if there are any dual stage thermostat that work with the A/Cs units. I am guessing the blower fan (DC Motor) is wired wrong in our home as it runs at different speeds when the dual stage furnace comes on (correct) but at single medium speed when the A/C is switched on (WTF?..I would like it blow more cool air). Has anyone else noticed that? We recently upgraded from a 65% efficient furnace (old) to a 93+ and couldn't be happier.

I am assuming with the A/Cs all blowers run at one speed. Anyone seen different?

Here is the "shiz nizzle": Click me

What SEER rating is your A/C, 13 or 14+ I will assume?

Dont know what the SEER is. will find out.

Thanks guys! I already bent over and went to Depot and paid $50 for a programmable Honeywell, so I'm good to go. The real question is whether to program it or not.

I checked it out last night. I have a 3 ton unit, 1550 sq. feet. 6 rooms of cooling. 13 or 14 SEER, I can't remember (it's a HEIL unit). The temp inside the house was 83 when I got in last night. I flipped on the A/C and it took 2 hours to cool down the house to 74. Outside temp had been ~87. It was cloudy out.

What I've done thus far is to set the t-stat to 78 during the day and 74 at 4pm. I arrive home around 5:15 so I figure thats an hour to get the house down 4 degrees.

The real question is how often the system cycles on and off during the day to maintain that 78 degree temp. Thats going to depend upon a lot of conditions -- sun, outside temperature, etc.

I need to get some more insulation in the attic before winter. House was built in '64 and has 3" of insulation :tsk:

Mick its probably the way they wired up the system. I know that in a friends house the heat blows at a slower rate than the A/C. Maybe its just a question of getting into the wiring of the blower fan and changing the wiring around? It sure would seem like it.

Ther are several different furnace configurations, ours has an infinately variable fan speed and I know they also make single and two speed fans. The installer sets up the fan speed when they program the control module for the system. I know they had ours screwed up on the initial install and we had to bring in a different HVAC company to get things straightened out. There are seperate programs for the heating and cooling as ours was initially doing the same as your although the cooling was on low speed all the time.