April Bill - Good and Not So Bad?

Howdy Readers-

Another month has passed (roughly) since my last post.  Time sure flies by doesn't it?  Well, it's been a COLD spring so far down in the Southeast US.  Only in the past week has it finally been above 60F consistently.  I say this as I glance outside where its supposed to be a high of 48F, gloomy, and rainy all day.  *UGH* 

Although the forecast does call for sun this weekend with temperatures in the high 60s.  Yippie!

So...let's see where we ended up this month, shall we?

April 2012
Total Energy Consumption:  704 kWh
Number of Days:  32
Average Daily Consumption:  22.0 kWh/day
Heating Degree Days:  117  (note:  only 14 days actual had HDDs)
Energy Consumption per HDD:  2.63 kWh/HDD (based on 14 days)

April 2013 (Mar 4 - Apr 2)
Total Energy Consumption:  737 kWh
Number of Days:  29
Average Daily Consumption:  25.41 kWh/day
Changed versus previous year:  -15.5%
Bill Savings vs 2012 Consumption:  -$0.52
Heating Degree Days:  444  (note:  28 days actual had HDDs)
Energy Consumption per HDD:  1.60 kWh/HDD 
kWh/HDD Savings vs 2012:  39.1%

OK...so at first glance, I did worse than last year.  I used about 16% MORE energy, but luckily it only cost me a whopping $0.52 more.  I think I can deal.  However, when you factor how cold it was this year as opposed to last year, then I'm doing just fine.  If I include the HDDs, I was roughly 39% MORE EFFICIENT than last year. 

 I will say that this was tricky to look at because I had to make an "executive decision" on how to quantify days that had zero HDDs.  For the month of April 2012, if I included all 32 days in my calculation, then it would have said I used ~6 kWh/HDD.  Yes, that's a valid number, but its highly skewed because for nearly most of the month had no heating was needed so it's only looking at my "base" consumption at the time.  So that doesn't give a good indication.  So instead I only used the number of days an actual HDD was recorded.  I did the same for my 2013 values.  This brought the values more in line for as shown below:

2011-2012
12/2011 = 2.16 kWh/HDD
01/2012 = 2.45 kWh/HDD
02/2012 = 1.90 kWh/HDD
03/2012 = 2.14 kWh/HDD
04/2012 = 2.63 kWh/HDD

2012-2013
12/2012 = 1.82 kWh/HDD
01/2013 = 1.75 kWh/HDD
02/2013 = 1.73 kWh/HDD
03/2013 = 1.45 kWh/HDD
04/2013 = 1.60 kWh/HDD

OK...so this makes sense to me.  I'm trending as expected.  So I'm going to consider this a "minor" victory. 

I really don't have any energy efficiency projects in the near future.  Closest that once could even consider may be new window shades in the upstairs.  As we prepare the nursery for the arrival of our twins, I would like to put in some nicer shades than the cheap versions (old school pull down things that I can never get it to stay when I pull it down).  I was thinking about window films.  I tossed in an example link.   I get a little security benefit from it (you can't just smash a window anymore as the window film holds the glass in place...at least for a little while) not to mention some privacy too.  An then there's the potential energy savings too.  We'll see...I contacted my local firm to see how much it would cost.  I'm just curious right now...but if the price is right, I may do it.    I'll let y'all know... 

 

Updated (Non-Official) HERs Rating

Unofficial HERs Index for my House

So the other day I was bored and came across my former HERs rating report completed last May.  The report showed my house had a rating of 71 which meant that it was ~55% more efficient than a typical existing home (HERs rating =130) and ~29% more efficient than a standard new home (HERs rating = 100).   Since I've done a whole bunch of projects since then (most notably the attic radiant barrier and the GE Geospring), I was curious what my new score would be.

So looking through the report, in the footer it noted that the report was completed using the "REM/Rate - Residential Energy Analysis and Rating Software v12.99".  Using Google, I input the information and found the website for the software.  As I hoped, they provided a download for the software.  So I downloaded v14.1.  It's a 90-day trial version that's full featured except I can't print anything.  That's fine by me...I'm just playing anyway.

Luckily, my previous energy auditor, AltruEnergy, had sent me the REM/Rate file for my house (*.blg).  This was great because it meant I didn't have to re-enter all the information from the report!  Time saver!  After opening the file and doing the all-important "Save-As", I verified that my previous HERs rating did not change (it didn't) and then I started updated.   I added the following:

• Added in R-5 to the foundation walls for the XPS I added this winter.
• Added in R-5 to the Rim and Band Joist via the XPS I added this winter (1^st floor only).
• Note:  I have not added ventilation to the crawl space yet.  I’m waiting for my spring tune-up.  At that time, my HVAC guy is going to install the new vent in the crawl space.  So I didn’t update that in the file.
• Added in Radiant Barrier to the ceiling (all except the small vaulted part in the bonus room) which I installed last fall.
• Updated water heater to be my GE Geospring (EF=2.4) which includes an extra R-10 blanket I added myself.   It also runs in series to maximize desuperheater production.
• Updated the geothermal system such that only 1 unit has a desuperheater (only the downstairs unit has one).
• Added in my new fridge.  I got one of those French door fridges.  Not only is it bigger than my old one, but it uses nearly half as much energy per year.
• I updated the dishwater information to reflect the actually kWh/yr via the Energy Guide.
•  I updated the dryer to have moisture sensing which it has.
• I updated the clothes washer with the actual information for my unit via the Energy Guide.
• I updated my lighting to be 100% CFL.  It’s really more like 80% CFL and 20% LED.  But there's no option for LED in the software.  My exterior and garage fixtures are all CFL also so I put those to be 100% compliant.
• I updated the ceiling fan CFM/watt to ~92 CFM/watt.  We have 5 ceiling fans in the house, all of which are energy star.  The old file said we only had 1.  I actually replaced the one in my master bedroom (which we use nearly every night in the summer) with one of those DC motor ceiling fans.  It uses 327 CFM/watt…which is about 3x better than other energy star ceiling fans!  It’s still on clearance at Home Depot online (Hampton Bay Winfield).

The results are below (it's also in the pic above if you were paying attention)...drum roll please....

Unofficial Home Energy Rating (HER) Certificate  Note:  The NO PRINT is because I'm using the trial version.

My unofficial revised HERs rating is a 54.  Sweetness!  So I'm nearly 50% more efficient that a new standard home.  And by energy star standards, my house is house is ~30% more efficient than a new standard home...assuming an energy star home is 30% more efficient than a standard home which would give it a HERs rating of 70.  In case you're wondering from the certificate above, I don't actually use $1,379/yr for energy.  I'm much below that ($1,091).  The above number is scaled for a family of 5.  There's only 2 of us now, although soon we'll be close with twins on the way.

Side note:  I'm not advocating that anybody else do this...I'm just an Engi-nerd that enjoys tinkering.  I did send my file back to my Auditor for a QA/QC check...so I will say these results are preliminary.  Although I'm not sure he'll say anything definitive just because he probably doesn't want to advocate for folks to use this software who don't know what they are doing.  Being a modeler myself, I understand that when it comes to models,  "junk in = junk out".  So if you don't know what you are doing, you could just producing useless numbers.

One of the nice things about having the software is that I can run some scenarios for projects that I was contemplating.  These include:

• Replacing the siding and including R-5 XPS insulation (continuous barrier)
• Replacing the windows with new Low-e, Argon filled windows
• Install Solar Panels

Replacing the siding and the windows is an expensive proposition.  The siding itself would be ~$15k while the windows would probably be another $10k. Well, the software essentially told me not to bother.  Adding in the extra R-5 on the outside walls only saved be $50/yr!  The windows were another $50.  Obviously, doing it for energy saving purposes does not make sense.  Maybe for the windows installing a window film would make more sense because its significantly cheaper and would reduce the solar heat gain in the summer and the heat loss in the winter.  The return on investment would be significantly better while providing a similar benefit, although definitely not as great.  But it would be a fraction of the cost...if you believe the websites it's 10% of the cost.  So $1k vs $10k.  That could be palatable for my wallet.

The only thing that did make sense was the solar panels....but I pretty much already knew that.  The panels lowered my HERs rating to a 43.  However, that's a $4-5k investment.

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.

Initial Energy Savings! 30-40%!

Probably for the first time....I was super excited to get my Duke Energy bill.  This is one of the first bills to really show all my energy efficiency work.  What was the results?

Last month I used 526 kWh.  That's lowest we've had since moving in and equals 17.53 kWh/d.  That's even lower than the previous month (593 kWh) when we didn't use the HVAC at all.

How are we doing compared to last year?

March 2010 vs 2011:  34% less <---some heating until late in the month
April 2010 vs 2011:  4% less <---didn't use HVAC at all
May 2010 vs 2011:  41% less <---cooling started late in the month

Just awesome!  I'm thrilled...it's showing all that work is cashing in.

I also decided to compare my energy usage between this home (built 1986, 2700 sf) versus our old townhome (built 2005, 1300 sf).  Note for the "old" townhome I had to convert natural gas usage to electricity equivalent because both hot water heater and cooking used natural gas.  It's an easy conversion...if you want to know...ask.    OK here's the total energy consumption between the two places:

Feb 2011 vs Feb 2009: 26% less
Mar 2011 vs Mar 2009: 39% less
Apr 2011 vs Apr 2009:  22% less
May 2011 vs May 2009:  26% less

How awesome is that?  Our older, larger home is more energy efficiency than the newer, smaller, townhome.  Frickin' awesome.  I'm excited to see what the next bill shows...until July!!!