HTPC Upgrade

My Ubuntu Linux Mythtv Home Theater PC (HTPC)

Hey folks-

So I finally was able to get my Dad (aka...someone with Linux experience) to help me set up my HTPC for maximum power savings.   So what's a HTPC or Home Theater PC?  Think of a Tivo or Digital Video Reorder (DVR) that your cable company makes you pay for.  Except this is homemade, stores significantly more than just TV recordings, but also my movies, music, and pictures.  Well...it will eventually...in my last upgrade I still have slacked in moving my pictures and music back over to it. 

OK...so after my last upgrade, I was able to reduce my overall power usage from 120W to 95W.  I use the term "overall" because the power usage is not just the PC itself. I have the following additional equipment:
1)  Network switch for multiple ethernet using devices
2)  HDPVR to record TV off the cable box
3)  Crappy Cable Box from Time Warner Cable
4)  Signal Booster because I have to split the Cable TV signal 4x
5)  HDHomerun tuner to record my local QAM TV

I also have a remote frontend unit (think mini-computer) that allows me to stream everything from the main HTPC to the downstairs TV.  That unit is small and only uses 19W.   I had already setup this frontend to 'sleep' when I shut off.

Well...of course, for me, 95W running 24x7 was not acceptable.  So I emarked on the next level of upgrade.  Luckily, this was a software upgade, not hardware.  With significant help from my Dad, we setup the HTPC to shut down between recordings.  So, once a recording is finished and it's been commercial flagged, the system reviews when the next recording is upcoming.  If its a long enough time (20 mintues), it will shut down the PC.  It will not shutdown the PC if (a) someone is logged in (such as when I'm using it) or (b) if the downstairs frontend is running.  So it's not going to shut down right in middle of someone watching a recording. 

It took a lot of tweaks to get everything operating right, but it seems to be running well. I have since grabbed a smart power strip to shut down as many accessories as I can when the PC shuts down.  This is mainly the HDHomeRun and the HDPVR.  I tried to use the signal booster, but I found out that if the Cable Box reboots, then it can't connect/fully reboot until the signal booster is on.  And it takes frickin' 8 minutes to boot!  So if I want to start recording something right away, I can't do it because I have to wait for the box to finish booting. 

So, what has this done for me?  Well, I just plugged in the Kill-a-watt meter and I've gotten some preliminary results.  They are as follows:

HTPC Running with all accessories:  95W
HTPC Off with all accessories:  41W
HTPC Off with some accessories off:  29W

Accessory Power Usage:
Signal Booster:  3W
Network Switch:  3W
Cable Box:  23W

Before I go on a rant about my #$*&# cable box, this is showing a 67% reduction in "always on" power usage.  More than likely this will end up being bigger when we factor in operational time and start talking killowatt-hours.  I just started collecting data so I don't have official results...but let's talk about some theorectical values (not counting the frontend since its the same usage regardless):

Before (Operating 24x7):
95W x 24 hrs/day * 1 kWh/1000W = 2.28 kWh/day

After (Assumes used 4 hrs/day:
95W x 4 hrs/day * 1 kWh/1000W + 29W * 20 hrs/day * 1 kWh/1000W = 0.96 kWh/day. (58% Energy Savings)

What did this cost me?  Well...i did have to buy a new solid state hard drive (SSD) for my frontend so I the system could shutdown instead of 'sleep'.  This also significanly sped up the reboot to something like 10seconds and allowed me to write some code that when the frontend turns on, it 'pings' the HTPC to turn it on.  After it waits for the HTPC to boot (that takes 10seconds), then it connects and starts Mythtv. That cost me $57. 

1.32 kWh/day savings * $0.10/kwh * 365 = $48.18/yr.  So my ROI is 1.18 years.  Yeah, I'll take that. 

Now for that &*#$& cable box.  I can't believe it uses 23W!  And the sad thing is that when you 'turn it off', it doesn't save any energy.  Seriously!!!! I checked it with the kill-a-watt meter!  Not even 1W.  Why is this device sucking down this much energy?!? And to top it off...why the heck does it take 8 minutes to boot?  I TIMED THIS!  In the age of superfast computers that use little energy this is ridiculous!!!  My frontend computer uses less energy (19W) and is equipped with a 30GB SSD, a dual core 1.8 GHZ processor, and boots in 10 seconds.  And it probably decodes HD TV faster.  It certainly makes you wonder what the heck is going on with these companies.  I know my TWC service blows and I'm just waiting for the day that there is sufficient competition in NC so they will come out of the dark ages.  My only real alternative is AT&T and their "digital" internet service is nearly half the speed of TWCs.

OK...*pant pant*...calm down boy....off the soap box.

The long story short...this was a fairly painless upgrade that'll knock off some kWh's.  With my new fridge knocking off about 0.5 kWh/day, I'm reduced my baseload usage by ~1.8 kWh/day.  My 'always on' energy usage is down to about 165W (3.96 kWh/day).  There's a couple things I can do to get this down a little futher, but not much.   At least 85W of this power is the upstairs and downstair geothermal systems on standby (~30W each) and then the frickin' cable box (23W).  Then there's things like the alarm clocks, the internet cable modem, and the router.  Yeah...these are staying on.  However, it would only take 500W of solar capacity to completely negate this energy usage.  We'll see when that happens....

December 2012 Energy Results

(I felt like the blog posting was boring so I tossed in a pic to liven it up.  Here my recent TED5000 Monitored Usage)

Hello Readers-

I hope y'all aren't still not choking down thanksgiving turkey.   Not me...but my dog is eating like a King.  Although I still think there's some gravy left in the fridge.  And let me tell you....Gravy tots....MMMmmmmmm....just saying...try it.

Back to business...I got my latest Duke Energy Bill in and the results are posted below.  It's another year of savings which is good! 

To the numbers...

December 2011 Bill
Total Energy Usage:  963 kWh
Days:  30
Average Daily Usage:  32.10 kWh/day
Billed Amount:  $92.00

December 2012 Bill (Nov 1 - Dec 3)
Total Energy Usage:  970 kWh
Days:  32
Average Daily Usage:  30.31 kWh/day (5.57% reduction from 2011)
Billed Amount:  $98.52
Absolute Savings versus 2011:  - $6.52 (you can easily see the rake hike:  7 kWh total difference is not at $0.93/kWh)
Rate Adjusted Savings versus 2011 @ 0.1056/kWh):  $10.84 (lower winter rates now).

Overall, there has been a savings, albiet small.  One thing to note is the totally different temepratures between 2011 and 2012.  It was definitely colder this year than last.  To address this I looked up the heating degree days (HDD) for 2011 versus 2012.   I used NOAA monthly climate data for Charlotte, NC posted here.

For the same time period (Nov 1 - Dec 3) in 2011, we had 446 HDDs.  This year we had 533 HDDs which is a 87 HDD increase.  To put this into perspective, let's compare the energy usage to the HDD.

For 2011: 
Energy Usage = 32.10 kWh/day
HDDs = 446
No. of Days = 30
Heating degrees (HD) = 14.87
Energy Usage per HD =   2.16 kWh/HD

For 2012: 
Energy Usage = 30.31 kWh/day
HDDs = 533
No. of Days = 32
Heating degrees (HD) = 16.66
Energy Usage per HD =   1.82 kWh/HD  (15.7% reduction)

Overall, the climate adjusted energy reduction is around 15.7%.  This isn't uber-accurate given that I'd need to subtract out non-temperature related energy usage to get a more accurate representation...but I don't have that data.  Thus, I've made the assumption that my lights/TV/cooking/etc usage has not significantly changed since 2011. 

November 2012 Energy Bill...Second lowest usage ever!

I'll tell ya...if I knew that changing out my hot water heater was going to make this big of a difference, I would have done it a long time ago.  Below is my energy usage information for the November 2012 Duke Energy bill:

November 2011 Bill
Total Energy Usage:  734 kWh
Days:  29
Average Daily Usage:   25.31 kWh/day
Billed Amount:  $73.20

November 2012 Bill (October 2 - November 1)
Total Energy Usage:  509 kWh
Days:  30
Average Daily Usage:   16.97 kWh/day (32.97% reduction from 2011)
Billed Amount:  $58.14
Absolute Savings:  $15.06
Adjusted Savings for Increase in Rates (@ $0.114/kWh):  $24.94

Recall in my October post, I noted that my previous low was in June 2011 where we used 526 kWh which equates to an average daily usage of 17.53 kWh/day.  So our November usage was again, lower than I previous low.  And last month, we had the heat on for at least half the month.

As for new projects, I posted about installing the Ecobee last month.  Following the data online, the system is certainly is maxing out the first stage, which is more efficient, as I want it to do.  

We also just bought ourselves a new fridge.  That will be installed next week and should reduce our energy usage by about 0.43 kWh/day.  Yeah...not a lot, but my fridge will bigger (it'll finally fit a platter) while still reducing usage.  And we got it $1500 cheaper (New @ Sears outlet + Energy Star Tax Weekend). I'm OK with that.

And I need to get back on the HTPC project.  I can get the PC to shutoff...but turning back on is an issue I'm still working on.  I did get myself a new router that'll allow me "wake-on-LAN"...which means it'll allow me to turn on the PC remotely when I want to say...set a new recording.  Again...this will take a while to figure out and I'm sure I'll require help from my Dad and Brothers as they are much more astute than I at Ubuntu Linux.

Ecobee Thermostats Installed!

Ecobee Thermostat Installed on my wall

I finally bit the bullet and bought the Ecobee Smart thermostats.  They were $260 each which wasn't too bad.  Installation was a little bit of a hassle. It was difficult because the instructions were not clear for my geothermal installation.  To me, it was not clear what Power went where. Below is a pic of the former Honeywell thermostat.

Pic of the wiring from the former Honeywell Prestige IAQ Thermostat

 Luckily, the Ecobee support team was great. I emailed them and they were very prompt in their response. We went back and forth a couple times (thank you Gus!) and eventually we found out that I only have 1 @ 24V power supply while the diagrams listed two supplies.  So I needed to run a jumper wire from one 24V input to the Ecobee to the other side of the control board.

Ecobee Control Module Installation.  I did clean the wiring up more after the pic was taken.

Once that was determined, it was a breeze.  The upstairs unit includes the flood sensor (the thick red wires on the bottom left in the above picture).  If the flood sensor registers a flood it will shut down the air handler AND will send me an email.  Pretty cool, huh?

Final Installation of the upstairs Ecobee Control Module.

Programming the Ecobee was very easy.  For the most part I kept the default settings that were recommended by Ecobee for a geothermal install (that was a menu option in the Installer Setup).  The only things I changed were the delta for when the system turns on/off and the Stage timing.  For the delta, I set it to be 1.5F instead of 1F.  For this I'm just sacrificing a little bit of comfort for more energy savings.  For the Stage timing, I set Stage 1 to run for a max of 2 hrs before Stage 2 turns on.  Stage 2 will run for 3 hrs before it calls for the emergency electric heat.  Thus, my system would have to run for 5 straight hours before it will call for the expensive, inefficient heat.  In addition, the system will stay on the most efficient stage as long as possible.

The web interface is pretty cool.  A pic of it is below.  I can pretty much change any setting I want from the portal.  And its generally much easier to do it here than on the thermostat.  Below is a pic of the thermostat settings.  The dark blue is "sleep", orange is "awake", green is "away", and light blue is "home".  So for Monday-Friday, the vast majority of the time is "away".  Then on weekends, I have more "sleep" and "home" time.

Ecobee Web Portal

 The only cool thing is that I can check out graphs on how my systems are operating.  I can see the setpoints, the indoor and outdoor temperatures, humidity and the system run time.  It's very cool.  The Ecobee site also produces monthly runtime reports and lets me know how my system is doing compared to other homes of a similar size and geographical location.  Since I've only had it installed for +/- a week I'll have to wait to show y'all the results of the report. 

Downstairs Themostat Operational Information

Upstairs Thermostat Operational Information

 The Operational data is all downloadable.  What would  be VERY COOL would be if I could link this system data with my TED5000 home energy usage data.  This would allow me to track exactly my energy usage from HVAC.  That's probably a task for someone smarter than I.

There's also a Android App that I use on my phone.  It essentially lets me change the temperature, turn the system on/off, check the weather or set a vacation schedule.  Below is a screenshot from the phone. I can easily switch between thermostats too.

Screenshot from Ecobee Android App

 What would be really cool would be if I could look at the Operational information from the App.  Right now the only way to to do it is to login to the website from my phone.  It's a little bit of a pain...but not too bad.

October Bill - Lowest Month Ever! - 39% Reduction

Hi All!

I've been excited to see what this month's results would be and it really blew my socks off.  It was my lowest energy usage month EVER in the new house.  It even compares to the days when I was living in my former townhome (which was built in 2005 with gas heating, cooking, and water heating).   The results are below:

October 2011 Bill
Total Consumption:  771 kWh
Days:  32
Average Daily Usage:  24.09 kWh/day
Bill:  $79.75

October 2012 Bill (September 4 -October 2nd)
Total Consumption:  409 kWh
Days:  28
Average Daily Usage:  14.61 kWh/day
Bill:  $49.91
% Reduction in Energy:  39.4%
Bill Savings (based on current average rate of $0.113/kWh) = $37.36

So this bill breaks the previous record set in June 2011:

Lowest bill:  $49.91 vs $53.54...and this includes a hike in rates!
Lowest Monthly Consumption:  409 kWh vs 526 kWh.  While June2011 has 2 more days in the billing month, if we tack on another 2 days at ~15 kWh/day I'd STILL be way under (439 kWh vs 526 kWh).
Lowest Average Daily Consumption:  14.61 kwh vs 17.53 kWh

I mentioned my previous townhome which was building in 2005 (1,300 sf, gas heating, cooking, and hot water).  If I compare the usage there in the "swing months" where I wasn't using any HVAC, I averaged 14.3 kWh/day (~414 kWh).   Recall...my current home is 2,700 sf built in 1984 with electric everything.  So needless to say, I'm thrilled that I've done so great.

Kudos to the GE Geospring ASHP Water Heater which was no doubt, responsible for helping me significantly reduce my consumption.  And to think that half the month was without it too...

Next up...I ordered my new Ecobee Smart Thermostats.  Once those come in and I set them up I'll have my HVAC system as fully optimized as I can get it along with monitoring.  I'll give y'all the low down in about a week when they arrive and I install them.

Also, I'm working on getting the HTPC to shutdown and wake up.  I can do it manually, but I just need to figure out how to get it going automatically.  I'm not a big linux guy so it'll take a while for me to figure it out. This task alone should save me an additional 1.84 kWh/day (13%)

New Hot Water Heater - Preliminary Results

TGIF  Readers!
(At least for me at the time of my typing..)

I've got some exciting preliminary energy reduction results!  Recall that about a week ago I installed the GE Geospring hot water heater.  Well, I've been watching the days closely and tracking energy usage and wow has the new hot water heater (and combo crawl space dehumidifier) making a difference.  Below are the graphed results:

As you can see above after turning off the HVAC system and before installing the hot water heater, energy consumption was around 20 kwh/d.  If I was to go further historically, you'd see this a lot.  Even during my lowest month (Spring, No HVAC, vacation for a week), I averaged 17.5 kWh/day.

After installing the unit, my average has plummeted to 14.5 kWh/day.  And me and my wife are still at home...no vacations...doing the same things we do every week (laundry, cook, clean the dishes, shower, watch TV, etc).  That's a 6 kWh/day or 29.4% reduction in energy usage.

Note that this average ignores the day we actually installed the unit (9/8) because the unit had to reheat all the water so that's why there's that big bump (when it first turns on, the startup cycle uses the electric elements to get up to temperature fast).  Also, I needed to make sure everything was OK with the desuperheater/piping/preheat tank so I bumped on the A/C for a short period of time.

OK...so what does this all mean? 

Well, 6 kWh/day x 30 days = 180 kWh/month x $0.113/kwh = $20.34/month in savings or $244/year.  I'll take that.  It's not quite the 9.33 kWh/day of energy reduction I had anticipated, however, this is at a hot water temperature of 130F while the former HW heater was set at 120F.  Why so high?  Well, I read in the Geoexchange forums that if the desuperheater/preheat tank increases the HW temperature to above the Geospring set temperature (which it can in the summer), the Geospring will error out and need to be reset.  With summer behind us and the HVAC off, I'll put the temperature back down to 120F.  I should have done this earlier (since I turned off the HVAC even before hooking up the Geospring!), but I was trying to be conservative to start.  

So, here's another thing...even with the Geospring temperature set so high, I'm still seeing significant savings.  Overall, I'm recording energy usage days at all-time lows (10.7 kwh/day!) even though I'm home.   At the current rate, it's looking like I'll only use 534 kWh for this month (17.8 kWh/d).  My all time low is 526 kWh/month (17.5 kWh/d) and that was during the Spring of 2011.  Note that most Springs I'm around 500-600 kWh while during the fall I'm typically around 700 kWh (~24 kWh/d).   

So what's next on the chopping block?  Well, installing the Ecobee thermostats will wrap up my optimization of the heating, cooling, and hot water systems.  I'm not going to do that until temperatures drop and I actually have to use my HVAC system...so that'll be mid- to late-October, probably.

Then after that I'll start looking at my next two biggest energy users...the HTPC and the Fridge.  From my latest Kill-a-watt readings that Fridge uses about 1.9 kWh/day.  That's about 11% of my current daily usage.  At best, a new fridge will knock that down to about 1.2 kWh/day (0.7 kWh/day savings).  I'm not rushing this investment because the ROI is just not there.  However, I'm not fond of my fridge (too small...even for only 2 people!) so that's why its on the chopping block.

My Mythtv HTPC.

Then there's the HTPC.  One average the HTPC (and all its accessories) is using about 1.6 kWh/day.  I'm looking into how to get the HTPC to 'sleep' between recordings and then 'wake up' when I watch TV.  I'll need a new Wireless Router for this ($100), but besides that it's all software and time to get this going.  Once I figure it out, I should be able to reduce average daily power consumption by around 80%. My ROI?  About 2 years due to the cost of the new wireless router.

Combined the fridge and the HTPC could knock off another, roughly, 1.98 kWh/day...or 11% reduction.  That would put me down to about 15.5 kwh/day average daily usage (currently).  That's pretty dang good for a house that uses all electricity (no natural gas).  Getting lower than this will be very tough (stop using the dryer??)

Then there's looking at solar panels...but that's a whole another story...   

Repost: Ecobee Smart Plug

 Wow...this is sooo cool.  I'm totally going to have to loook into getting one of smart plugs when I get my Ecobee Smart thermostat.  Of course, I'd have to figure out what exactly I'd plug into it first.

Kudos to Chris @ mapawatt.com for this review:
http://mapawatt.com/2012/08/12/ecobee-smart-plug-review/

New GE Geospring Hot Water Heater!

My new GE Geospring hot water heater in series with a preheat tank (not shown)

So I finally put in a new hot water heater.  As I had discussed in previous posts, I wanted a GE Geospring air source heat pump (ASHP) hot water heater.  Well, that's what I got.

Why am I so hyped about this?  Well for starters...

1)  The Geospring is rated at an energy factor of 2.5 which saves roughly 63% of the energy as compared to normal electric hot water heater (which I had).  On an annual average basis, my former HW tank was running 0.8 hrs/day @ 4.6 kW for 3.7 kWh/day.  Thus, this is expected to be reduce to 1.37 kWh/d.  

2) I had mentioned in some of a previous posts, that the geothermal supplemental hot water generator (desuperheater) really is not optimized when using one tank.  I'd read some forums that even claimed it could be costing me energy with calls for geothermal system manufacturers to remove the 1 tank setup from its installation procedures.   Well, this new hot water tank was connected in series with my "old" hot water tank (now un-powered).  The "old" tank will act like a preheat tank allowing for maximum hot water generation via the desuperheater.  This preheated water will feed the GE Geospring.  So overall, the energy required for hot water generation is cut substantially.

3) The Geospring is so efficient because its an ASHP hot water heater.  Essentially that means its an air conditioner connected to hot water heater.  So it will "condition" (remove heat and humidity) the air and instead of discharging the heat outside, it takes the heat and pumps it into the hot water tank.  Why does this benefit me?  Well, recall I've been using a dehumidifier in my crawl space to reduce moisture...and its been a fairly large energy consumer.  Well, the Geospring will now take the place of the dehumidifier by simultaneously conditioning the air (removing moisutre) as it heats the hot water.  Thus, I'll hopefully be able to negate using the dehumidifier entirely! That should save me somewhere around 7 kWh/day alone.

Overall, I'm hoping this work will reduce my overall power consumption by about 9.33 kWh/day.  It could be higher including optimization of the desuperheater, but I have not way to quantify this yet.  Even at 9.33 kWh/day this is about 280 kWh/month!  If you consider that in the last year (Sept 2011 - Sept 2012), I've averaged 853 kWh/month, then the 280 kWh/month will result in a roughly 33% reduction in consumption!  That equates to roughly $31/month.    This project cost me about $1200 to install, so that's a 3.19 ROI (not assuming any rate increases).  I'll take that... Only time will tell what I actually achieve...   

 

August Energy Savings = 18.5%

The August Dook Energy Bill is in.  The results are good!  See below:

August 2011
No. of kWh Used:  941 kWh
No. of Days:  31
Average Daily Energy Consumption:  30.35 kWh/d
Bill:  $90.95

August 2012
No. of kWh Used:  816 kWh
No. of Days:  33
Average Daily Energy Consumption:  24.73 kWh/d
Energy Savings vs 2011 = 18.54%
Bill:  $91.17
Bill Savings (converting 2011 Bill to 2012 rates) = $13.97

Still Looking great!  My 2012 average savings is 26.10% (36.7% not looking at the fringe seasons)

July Energy Bill - 20.33% Savings over 2011

Update:  I just noticed this was labeled June, not July.  I've updated this post with the correct information.  Sorry for any confusion!

My dook energy bill came in yesterday and below are the results:

July 2011
Total kWh:  888
No. of Days:  28
Average Usage = 31.71 kWh/d 
Bill = $86.97

July 2012
Total kWh:  758
Days:  30
Average Usage = 25.27 kWh/day
Bill = $85.62

% Reduction from 2011 = 20.33%
Bill Savings:  $1.35

While this looks great, I need to preface that I went on vacation for 10 days so there's no doubt that has an effect on my total usage...especially since June was VERY HOT. 

Y'all may have noticed that I put in the bill savings too, but that isn't a good indicator given that rates have increased over 2011.  The way to think about the difference is rates is to do the simple math:

2012 Cost per kWh:  $85.62/758 = $0.11295 (say $0.113/kWh)
2011 Cost per kWh:  $86.97/888 = $0.0979/kWh
Increase in rates:  15.4%

July 2012 Bill if still at 2011 Rate:  758 kWh * $0.0979/kWh = $74.21.  Savings compared against 2011 if still at 2011 Rate:  $12.76. 

OR 

July 2011 Usage at 2012 Rates:  888 kWh * $0.113/kWh = $100.34.  Savings compared against 2012 based on 2011 Usage = $14.72

I'm sure we could play with the math more and create other ways to look at it, but I'll stop here.  To-the-Point:  We saved energy and money. 

Radiant Barrier



Radiant Barrier in the attic

 So last weekend, I teamed up with one my friends and installed a radiant barrier in both our attics.  It was a fairly easy project.  His attic has gables and a single gable mounted attic fan (no soffits), so we put the radiant barrier directly over the insulation.  In my attic (has soffits and attic fan), I had a contractor install  ridge vent and then I stapled the radiant barrier to the joists except for the small attic space over my bonus room, where I installed the radiant barrier over the insulation.
 
Like I said...it was an easy project.  Luckily, it was cool outside so we didn't kill ourselves, although I did sweat up a storm.  Above the attic duct work (which is high) we "tented" over it to keep the heat away.  I used atticfoil.com for the radiant barrier.  It was a good product and i have no complaints.



Looking at the top of the attic.  You can see my high duct work and the "tent" over the top

 I can't say for sure how well it is doing, although today when I came home after a hot day (sunny and a high of 91F),  I noticed for the first time since I can remember, the attic fans  were not on when I walked upstairs and the temperature was 82F (thermostat set at 84F).  Nearly all summer when I came home the upstairs temp was 84F and the HVAC was cycling.    We'll see after August and September.

June Energy Usage

Sorry for the delay!  My wife getting the ebills and not a paper bill means I don't get the energy data as fast as I'd like.  Not to mention I went on vacation.  Below are the energy results from June

June 2011
Total Power =  1086 kWh
No. of days = 33
Avg Power/day = 32.91 kWh/day

June 2012
Total Power = 663 kWh
No. of days = 29
Avg Power/day = 22.86 kWh/day

Savings compared to 2011 =  30.53%

So, it looks great.  However, I'm not getting too excited given that that May was fairly cool and so far we've been sweltering this month.  

LED light bulbs

OK, so I'm finally fully LED or CFL in the house.   Due to the energy efficiency lighting grant, I got myself some MR16 and candelabra bulbs among the other bulbs i ordered for the neighborhood.   So i gotta say...they look great!  I thought i might be disappointed...but no!

I posted some pics below.  The MR16 are Slyvania 5.5w bulbs (from Lowe's) which replaced 50w bulbs.  So that's 27.5w instead of 250w or a 89% reduction.  One issue is that these are non-dimmable apparently because they buzzed something awful until i replaced the dimmer switch.

Our kitchen light with the 5@5.5W LED bulbs, an 89% energy savings

Now the other lights are using the candelabra bulbs.  I put these into the chandeliers in our breakfast nook and dining room as well as our entry light.  Combined those used 620W through a combination of 11@40W and 3@60W bulbs.  They were replaced with Utilitech 3.5W bulbs (dimmable!) which now total 49W or 92% savings.  They were easy to install, even though removing those individual little light shades on the chandeliers was annoying.  Pics are provided below.

Our breakfast nook chandelier (ignore the mess, please)

The dining room chandelier.  Looks nice!

Optimize Geothermal with new Thermostat?

So I've mentioned this before in previous posts, but I'm not too happy with my Honeywell Prestige HD thermostat.  It's pretty looking, yes.  But for being a $300 thermostat, it's control options are not all that great. 



Honeywell Prestige HD Thermostat

One of things that I'm most unhappy about is the inability to control how the unit calls for Stage 1 and Stage 2.  Why is this important to me?  Well, Stage 1 is more efficient than Stage 2.  And it seems whenever I walk by the thermostat, the unit is registering that Stage 2 is running. 

Let's take a closer look....

In Cooling mode, Stage 1 has an EER (Energy Efficiency Rating) of 26.8 while Stage 2 is 18.6.  So Stage 1 is 44% MORE EFFICIENT than Stage 2. (FYI..in terms of SEER, Stage 1 should be about a 31 and Stage 2 is 21).  However, Stage 2 has a greater capacity:  27,200 BTUh vs 21,500 BTUh.  So Stage 1 would have to run 1 hour and 15.9 minutes to achieve the same heat transfer as Stage 2 in 1 hour.  However, even if you factor in the longer run time, Stage 1 is still 31% more efficient than Stage 2.  So it's definitely beneficial to run Stage 1.  This assumes that the desuperheater benefit is the negligible, which in reality probably factors Stage 1 (longer run times means closer to steady state operation and higher heat transfer efficiencies).   And longer run times and means less Start and Stops on the compressor which is beneficial to maintenance. 

Now let's look Heating.  This benefit is no where near as great.  Stage 1 has a COP (coefficient of Performance) of 4.7 while Stage 2 is 4.2.  This translates to a HSPF (Heating Seasonal Performance Factor) of 16.05 for Stage 1 and 14.34 for Stage 2, so Stage 1 is about 12% more efficient,  Stage 1 has a heat transfer rating of 16,200 BTUh while Stage 2 is 19,500 BTUh. So Stage 1 would have to run 12 minutes longer to achieve the same heating as Stage 2.  Inclduing the extra run time, Stage 1 is still 10.6% more efficient.  Now, if I assume the desuperheater is running scalping 5% of Stage 1 (it automatically turns off for Stage 2), then the savings plummets to 5.9%.  But it's still a savings, albiet small. 

So what does this mean in terms of dollars? I create the following table below using the 2011 Cooling Bills.  The savings do not include the last 7% increase in Duke Energy rates for this summer.

2011 Summer Cooling Bills:
	Energy	Days	kWh/d	Bill	Rev Bill	Savings
06/01/11	1086	33	32.91	103.14	71.58	31.56
07/01/11	888	28	31.71	86.97	60.36	26.61
08/01/11	941	31	30.35	90.65	62.91	27.74
09/01/11	771	32	24.09	79.75	55.35	18.30	(Red by 25%)
					total	104.21	per year
2011 Winter Heating Bills:
	Energy	Days	kWh/d	Bill	Rev Bill	Savings
11/01/11	963	30	32.10	92	86.54	5.46
12/01/11	1318	33	39.94	121	113.82	7.18
01/01/12	1075	29	37.07	103.18	97.06	6.12
02/01/12	1051	29	36.24	107.9	101.50	6.40
					total	25.17	per year
			Estimated Total Annual Savings	129.37	per year

So during the 2011 summer months, there's a chance for about $100 in savings.  During the winter...not a lot at only $25.  I could roughly double the winter savings if I disabled the desuperheater in the winter.  Overall...even at $125/year that's not bad at all.  A HUGE decrease...no...but still measureable.



Ecobee Smart Thermostat.  It also has web-enable features too.

 So how can I fix this?  Well, I was looking at the Ecobee Smart thermostat.  This thermostat would allow me to set Upstage timers such that the system will stay in Stage 1 as long as possible as long as it doesn't violate any rules (such as...the temperature continues to rise or drop by X degreesd during operation or the timer doesn't "time out' before reaching the goal temperature). 
If I go with the Smart thermostat, then it could cost me about $600 ($300/thermostat).  Being conservative, the ROI would be about 5 years.  If I were to go with the Smart's new cousin...the Smart Si (not nearly as cool as the Smart, slighly harder to install, etc)...then the ROI would be 3 years as the thermostats only cost about $200 each.  I could also do one of each too. 

And all of that is before I talk about the really cool (nerdy) features such as reports that track the inside temperature, your setpoint, and the systsem run time.  And it's web-enabled so I can control it from anywhere (my wife will not be happy about that)

What do y'all think?  The downside is that my thermostats are brand new...however that could be a blessing because I could probably sell them to offset the cost of the new one. 

Energy Audit Results! HERS Index = 71

Well, I finally got my energy efficiency results in....drum roll please....

I got a HERS index rating of 71. 

So, what does this mean?  Well, let's start with the basics...HERS (Home Energy Rating System) is the standard by which a home's energy efficiency is measured.  Here's a good explanation:  http://www.resnet.us/hers-index

From above my house is roughly 30% more efficeint that a standard newly built home in the US (HRES = 100).  As compared to "existing homes" (HERS = 130), I'm about 55% more efficient. 

Based on ASHRAE 90.2 (1993) Annual Energy Consumption Compliance, my home surpasses the minimum compliance by 22.1%.  For a house of my size, ASHRAE has an annual consumption score of 2,197 while my house has a score of 1,737.  My house also exceeds 2003 IECC compiance by 10.3% (IECC = 67.9 MMBTU vs 60.9 MMBTU).

The blower door test confirmed by infilration at 0.29 ACH (Natural).  This exceeds the ASHRAE 62.2 standard of 0.35 ACH. This also means that I need some mechanical ventilation because my house is becominng 'too tight'.  An Energy Recovery Ventilator (ERV) was recommended to maintain "healthy air".

What else was recommeded?  See below:

1) Radiant Barrier in the Attic to reduce radiant heat loads to the upstairs and to the upstairs HVAC system.  (I was planning on this, however, I need a ridge vent first so all the hot air can be directled out of the attic efficiently).
2) Tighten the ducts on the first floor (I already knew this and this should already be fixed when I HVAC taped the filter door shut.
3)  Install ERV (see previous comments).
4)  Seal all holes/cracks/ and seams @ the Garage to the House.  (I'm not sure what this means since we didn't find any cracks/seams with the garage).
5)  Block joists at rim band at bay windows (OK...I can probably do this with some polystyrene foam board)
6)  Block Floor Band at Bay Window with blue board and foam (Same as #5 as I can best figure)

7)  Conidtion Crawl space to improve HVAC performance.  (I was getting to this.  I just need to insulate the crawl space walls and I'll be ready to allow some conditioned air into the crawl space.
8)  Condition attic to improve HVAC performance.  (I have no intention of doing this.  At most I'm planning is the radiant barrier- #1).
9)  Replace windows to improve wall u-value.  Yeah...at most I'll probably just replace all my window shades to be the "light filtering" double wall cellulose shades.  These should increase the R-value of the window (with the shade closed) substantially.

What I found interesting was the annual energy profile:

 One note...due to RESNET standards (I believe), this is based on a worst case scenario (4 bedrooms + 1) Family of 5 living in my house.  So I'm not actually spenting ~$1750/yr on my home.  Last year is was only $1050.  And the "Family of 5" is what is pushing my Lighting and Appliances up so high.

This table is neat because it says what's contributing to heating/cooling. 

So ignoring lights/appliances for now since it's way overinflated...this essentially shows that heating is predominate followed by cooling and water heating.  To reduce heating costs, it appears I need to do the siding project which would reduce infiltration and add insulation to the above grade walls.  However...if you really think about it...that project doesn't save me such.  Let's say I can reduce the infiltration and wall costs by 50%...That only saves me $137 per YEAR.  The siding project will cost me at least $10k for an ROI of 73.3 years.  Yes, it will make my house look nicer, but it isn't the energy monster I was hoping for.

For cooling, I really don't have a big winner unless I can reduce the internal gains...uhh...how do I do that?  Stop the fridge?  No indoor cooking during the summer?  Sleep outside?

And then there's hot water.  If I install one of those air source heat pump hot water heaters (such as a GE Geospring) then I could probably reduce that number to about $90/year.  And if you count reducing the crawl space dehumidifer usage by 50%, then I get about $180 per YEAR savings.  Yes...again...not a lot..even with the further optimization of my geothermal desuperheater (using two tanks in series).

Going back to the lighting and appliances.  If I look at the months that I am not using any HVAC, I'm essentially using 610 kWh/mo (20 kWh/d) of electricity.  About 30% of this goes directly to the crawl space dehumidifier (6 kWh/day).   Then there's hot water which is currenly about 20% (4 kWh/day).  So 50% is going to two things. Best as I can tell...after that is the fridge (709 kWh/yr * 1/365 = 1.94 kWh/d), the HTPC (1.64 kWh/d), then the dryer (6 kW * 1.5hrs/week * 52 weeks/365 days = 1.28 kWh/day).  Then maybe we have cooking (who knows where this math pans out...maybe 1 kWh/d?) and then freezer at 0.7 Kwh/d. 

So if I really want to make a large dent in my energy usage, my next target really should be the Air Source Heat Pump Hot Water Heater which should save me roughly 2,000 kWh/year (5.5 kWh/d) if I assume a 60% reduction in hot water generation cost (using GE's value) and a 50% reduction in dehumidifer usage since the hot water heater is a glorified dehumidifer.   I'm more than liklely going to hold off on this project until November for the "Energy Star Tax Holiday" in NC where we get a tax free day for Energy Star appliances.  The total project cost will probably be about $1.2k.

May Energy Usage, Dehumidifer

Hello all, I'm back.

Below is my May 2012 Energy Usage numbers from Duke Energy:

Total KWH:  689  (TED measured = 696 kWh)
No. of Days:  33
May 2012 Average Daily Usage:  20.88 kWh/day
May 2011 Average Daily Usage:  17.53 kWh/day
Comparison:  -19.1%

I'm not surprised by these numbers.  It was a hot May and we were forced to use our A/C for at least a week.  In addition, in May 2011, I had not yet installed the crawl space dehumidifier.  That was installed on June 6, 2011 (exactly 1 year ago...look at that).  One thing I have found since then, is that the dehumidifer is an energy hog (and it's Energy Star rated!).  I plugged it into my Kill-a-watt meter and measured the usage for  a couple days.  I found out that the unit is using roughly 7 kWh/day.  Wowza!  That's 33% of my average daily usage during the 'fringe' seasons (when the HVAC is not in use).

So what do I do about it?  Well...I think the only thing I CAN do about it, is to go ahead with my house residing project.  When I do this, I plan to install housewrap (maybe even some polystyrene insulation).  The housewrap is supposed to help reduce air movement (and thus MOIST air movement) which should help significantly and reduce crawl space dehumidifer usage.

Why do I think that?  Well...here's my thoughts:  When I turned on the A/C (which dehumidifies) last month I did not notice any reduction in crawl space dehumidifer usage (and I was watching)...as my initial theory was that the rest of the house was responsible for the permeation of humidity in the crawl space.  To test this out,  moved the dehumidifer to the house and ran it.  Guess what?  The crawls space humidity increased to 65% (slowly) even though the rest of the house was at 55%.    So that wasn't it...so my next theory formed...the humidity is entering the crawl space from the wall cavaties.  This would make sense because the walls terminate at the crawl space.  Because I have painted walls (who knows how many layers), this creates a fairly impermeable membrane on the interior walls...so where does the humidity go?  Well...down to the crawl space where the dehumidifer is drawing air and creating a gradient.  Thus, by putting on the houswrap/insulation...I'll create an effective air barrier on the EXTERIOR walls...which should significantly reduce the amount of moist air entering the crawl space. And I'm certain air is entering the wall cavity beause most of my exterior lights have holes directly to the interior wall. 

That re-siding project is going to be pretty expensive ($8-10k), but at least it will help my house look nice while simutaneously increasing energy efficiency.  I highly doubt I'm going to emark on the project soon.  Maybe this fall at the earliest...

Energy Audit #2

OK...so I had another energy audit on Tuesday (it was free). This was one of those full-blown audits.  I got this as part of an energy grant I won for my neighborhood.

Essentially...if I did my math correctly...my house is fairly tight and is just above Energy Star 2.0 standards (ACH50 = 5.1; Energy Star 2.0 <5.0).  You certainly can't complain about this given that New Homes barely meet this standard with existing homes (like myself) are generally have ACH50's in the 10-20 range.  BTW...ACH50 is "Air Changes per Hour at 50 pascal".  That's the blower door test standard which simulates the pressure differential with a 20 mph wind.  I found this table online (I've yet to re-find it...if I do, I'll post the reference) which is a good description.

 

ACH50	Natural Air Change	Rating	% of Energy bill	% savings potential	Ventilation requirements
1.5	0.075	Super	2%	none	Requires constant energy recovery ventilation
3.5	0.18	Excellent	6%	1 to 3%	Will require occasional forced ventilation
5	0.25	Better	10%	2 to 4%	May require occasional forced ventilation
7	0.35	Good	14%	2 to 5%	Does not require additional ventilation
10	0.50	Fair	20%	3 to 10%	Start of excessive energy loss and over -ventilation
20	1.0	Bad	40%	5 to 20%	Excessive energy loss and over –ventilation.

The duct blaster showed my upstairs ductwork was better than energy star (3.69 CFM vs Energy Star <4 CFM) with the downstairs ductwork at 7.8 CFM****. 

**** We found after the test that the door to the filter at the downstairs airhandler was had some big gaps/leaks.  I have HVAC-taped over the gaps when I reinstalled the filter.  It's expected that these leaks were the cause of the unexpectedly high leakage...and now the downstairs ductwork should meet Energy Star standards. ****

 We'll see what the final results say...but I'm guessing it's going to say that my house is doing pretty well.

One thing I was hoping for, was that going through this exercise would identify my next project.  Well...it kind of didn't.

When we walked through the house with the IR camera (blower door maintaining -50 pa), we really didn't spot any significant air leaks.  That's good, right? There were some very small spots, but nothing to raise an eyebrow at.  And those small spots I can most likely fix with a small tube of caulking. 

So where does this leave me? 

Most likely I'm still doing the following projects:

1) Geothermal hot water heater.  This is adding in the second tank to optimize hot water generation
2) Insulate crawl space walls (R10) and make the crawl space part of the building envelope.  This should keep my downstairs wood floors warmer during the winter.
3)  Siding and housewrap.  I still want to replace my siding with Hardiplank really for looks.  But while I'm at it, I'm probably going to add in an air barrier.  Given my results...a simple housewrap will probably be sufficient (per my previous posts I was looking at adding in some rigid insulation).  From the Table above...I really don't have much % savings potential left.  So the simple housewrap should put me firmly in the ACH50 <5 catagory, if not approaching a ACH50 of 3.5. 

I should get the results of the audit next week...and of course, I'll fill y'all in on the details...

Happy Memorial Day1