Advice on cutting my cooling costs

trikkonceptz · 08-20-10, 02:10 PM

I have recently moved into a new temporary home. My original house was a 2 story town home, it was the corner unit and through all our best efforts of saving energy, bulbs, timers and smart usage I was able to sustain the house at a comfortable 850kw hours per month.

Well this new dwelling is a stand alone house and larger than my old home, we have employed all our tricks and tips from the old house and just got our first true usage electric bill. It was a whopping 1536kw hours. We were in shock to say the least.

Furthermore we are blaming the a/c unit. It is a 13 seer unit and it runs alot even when we keep the thermostat at 79 and runs more at night when we turn it down to 74 after 10pm.

So my initial thoughts were to run down to the local Home depot and buy a couple of 52" ceiling fans for $20 each and install them in the large attic I have. The entire roof has vents in it making the air easy to escape.

Leaving the house hotter than 80 degrees is simply not an option, so what are your opinions on using ceiling fans in the attic as a low cost alternative to much more expensive attic fans ..

I have access to a master electrician who is a family member and will help with any bizarre projects I dream up..

Thanks

gasstingy · 11-04-10, 07:39 AM

Sorry we didn't seem to have any ideas to offer on your electricity usage problem. Did any of your investigating come up with ideas that made a noticeable improvement?

I can tell you that where I live, August of this year was my highest electric power bill to date. While my usage was a good deal less than yours (810 kwh), I heat water with gas and my heat pump seer is only a 12. We are pretty well insulated and have big porches shading the windows though. I'm still looking for ways to reduce my consumption.

Piwoslaw · 11-04-10, 07:54 AM

Trik, I think Gasstingy is on to something: insulation plus shading. Put insulation on the attic floor and a heat shield on the underside of the roof. Add awnings to your southern windows (and probably on the east/west too). Calculate the length and angle of the awning so you get maximum shade in the summer and maximum sun in the middle of winter. Maybe use a PV panel for the awning material, killing two birds with one (expensive) stone? Are your windows of the double-pane, low-e variety? Is insulating/weatherproofing the walls an option?

Oh, and plant some fast growing trees just south of the house.

Patrick · 11-04-10, 08:06 AM

Quote:

Originally Posted by trikkonceptz

I have recently moved into a new temporary home. My original house was a 2 story town home, it was the corner unit and through all our best efforts of saving energy, bulbs, timers and smart usage I was able to sustain the house at a comfortable 850kw hours per month.

Well this new dwelling is a stand alone house and larger than my old home, we have employed all our tricks and tips from the old house and just got our first true usage electric bill. It was a whopping 1536kw hours. We were in shock to say the least.

Furthermore we are blaming the a/c unit. It is a 13 seer unit and it runs alot even when we keep the thermostat at 79 and runs more at night when we turn it down to 74 after 10pm.

So my initial thoughts were to run down to the local Home depot and buy a couple of 52" ceiling fans for $20 each and install them in the large attic I have. The entire roof has vents in it making the air easy to escape.

Leaving the house hotter than 80 degrees is simply not an option, so what are your opinions on using ceiling fans in the attic as a low cost alternative to much more expensive attic fans ..

I have access to a master electrician who is a family member and will help with any bizarre projects I dream up..

Thanks

I don't think that ceiling fans in the attic space will help much, if at all. You need to force that hot air outside of the attic space and draw fresh cooler air in. I think you'd be better off taking the money you'd spend on ceiling fans and putting that toward a real attic fan, perhaps a solar powered one. JMO, let us know how what you did turned out.

Ryland · 11-04-10, 09:06 AM

First step is to figure out where your house is getting heated from in the summer, it sounds like your house is most likely either poorly built or of a poor design, but if it's not then check to make sure that your A/C is working correctly, if it has a leak in it or some other problem it's going to run alot more then needed and not cool like it was designed to.

AC_Hacker · 11-04-10, 09:43 AM

Might try putting a soaker hose on the roof peak. Use a timer to give you short intervals of water. The periodic evaporation can really help cool the building.

-AC_Hacker

Phantom · 11-04-10, 12:14 PM

Build an open air awning for the A/C possibly with the roof having some open slats on it like louvers on the back windows of old cars. This will help if the A/C unit is in the sun during the day to help it cool, if it is shaded this will not help.

Ryland · 11-04-10, 05:15 PM

In fixing any problem you need to first figure out what the problem is, a symtem is that your bills are high but you need to figure out what is broke before you start tossing repairs at it.

mrd · 11-26-10, 03:54 AM

Attic fans are discouraged by many builders, as they create a negative pressure and suck conditioned air out of the house. The negative pressure may or may not outweigh the reduced delta-T of a cooler attic, and positive house pressure in the summer is preferred.

Sealing air leaks is always beneficial, and solar shading can make a tremendous difference in the amount of heat your air conditioner fights to remove. Also, an air conditioner that runs constantly is actually desired (as long as it can keep the house at your desired temperature) as it does a better job of dehumidifying the longer it runs.

Ryland · 11-28-10, 05:07 PM

Quote:

Originally Posted by mrd

an air conditioner that runs constantly is actually desired (as long as it can keep the house at your desired temperature) as it does a better job of dehumidifying the longer it runs.

Your A/C should run only half time as most are not designed for 100% duty cycles, a leak in the a/c lines, or a poorly installed a/c system would tend to cause it to run full time.
It also sounds like large house that has issues, if it was built in the or 90's then that is most likely the case as so many short cuts were taken that it might be cheaper just to move on, or burn it down.
but really, to spend your money wisely you might be best off getting an energy audit done, $300 and you will find the issues.

08-20-10, 02:10 PM	#1
trikkonceptz Helper EcoRenovator Join Date: Jul 2010 Posts: 44 Thanks: 3 Thanked 1 Time in 1 Post	Advice on cutting my cooling costs I have recently moved into a new temporary home. My original house was a 2 story town home, it was the corner unit and through all our best efforts of saving energy, bulbs, timers and smart usage I was able to sustain the house at a comfortable 850kw hours per month. Well this new dwelling is a stand alone house and larger than my old home, we have employed all our tricks and tips from the old house and just got our first true usage electric bill. It was a whopping 1536kw hours. We were in shock to say the least. Furthermore we are blaming the a/c unit. It is a 13 seer unit and it runs alot even when we keep the thermostat at 79 and runs more at night when we turn it down to 74 after 10pm. So my initial thoughts were to run down to the local Home depot and buy a couple of 52" ceiling fans for $20 each and install them in the large attic I have. The entire roof has vents in it making the air easy to escape. Leaving the house hotter than 80 degrees is simply not an option, so what are your opinions on using ceiling fans in the attic as a low cost alternative to much more expensive attic fans .. I have access to a master electrician who is a family member and will help with any bizarre projects I dream up.. Thanks

11-04-10, 07:39 AM	#2
gasstingy Journeyman EcoRenovator Join Date: Feb 2010 Location: Arab, AL Posts: 491 Thanks: 109 Thanked 49 Times in 43 Posts	Sorry we didn't seem to have any ideas to offer on your electricity usage problem. Did any of your investigating come up with ideas that made a noticeable improvement? I can tell you that where I live, August of this year was my highest electric power bill to date. While my usage was a good deal less than yours (810 kwh), I heat water with gas and my heat pump seer is only a 12. We are pretty well insulated and have big porches shading the windows though. I'm still looking for ways to reduce my consumption.

11-04-10, 07:54 AM	#3
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Trik, I think Gasstingy is on to something: insulation plus shading. Put insulation on the attic floor and a heat shield on the underside of the roof. Add awnings to your southern windows (and probably on the east/west too). Calculate the length and angle of the awning so you get maximum shade in the summer and maximum sun in the middle of winter. Maybe use a PV panel for the awning material, killing two birds with one (expensive) stone? Are your windows of the double-pane, low-e variety? Is insulating/weatherproofing the walls an option? Oh, and plant some fast growing trees just south of the house.

11-04-10, 09:06 AM	#5
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	First step is to figure out where your house is getting heated from in the summer, it sounds like your house is most likely either poorly built or of a poor design, but if it's not then check to make sure that your A/C is working correctly, if it has a leak in it or some other problem it's going to run alot more then needed and not cool like it was designed to.

11-04-10, 09:43 AM	#6
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Might try putting a soaker hose on the roof peak. Use a timer to give you short intervals of water. The periodic evaporation can really help cool the building. -AC_Hacker

11-04-10, 12:14 PM	#7
Phantom Apprentice EcoRenovator Join Date: Sep 2010 Location: Louisville, KY Posts: 101 Thanks: 13 Thanked 8 Times in 7 Posts	Build an open air awning for the A/C possibly with the roof having some open slats on it like louvers on the back windows of old cars. This will help if the A/C unit is in the sun during the day to help it cool, if it is shaded this will not help.

11-04-10, 05:15 PM	#8
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	In fixing any problem you need to first figure out what the problem is, a symtem is that your bills are high but you need to figure out what is broke before you start tossing repairs at it.

11-26-10, 03:54 AM	#9
mrd Apprentice EcoRenovator Join Date: Feb 2010 Location: Milford, DE Posts: 106 Thanks: 5 Thanked 9 Times in 9 Posts	Attic fans are discouraged by many builders, as they create a negative pressure and suck conditioned air out of the house. The negative pressure may or may not outweigh the reduced delta-T of a cooler attic, and positive house pressure in the summer is preferred. Sealing air leaks is always beneficial, and solar shading can make a tremendous difference in the amount of heat your air conditioner fights to remove. Also, an air conditioner that runs constantly is actually desired (as long as it can keep the house at your desired temperature) as it does a better job of dehumidifying the longer it runs.