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 

Repost: Tankless Hot Water Heaters

I read this today and found it interesting.  The key take away point...the way they measure "EF" (energy factor) for hot water heaters is very unreaslistic.  So if you think you're purchasing a tankless hot water heater that is has an EF of 0.95...you may be in for a surprise as real world measurements have shown this to range between 0.62 and 0.89. 

http://www.greenbuildingadvisor.com/blogs/dept/musings/are-tankless-water-heaters-waste-money

Here's a link to the published data too:

http://www.mncee.org/getattachment/7b8982e9-4d95-4bc9-8e64-f89033617f37/

April Bill

Hey all-

The April Duke Energy Bill just got in...results are posted below:

April 2011
Total KWH = 593
# of Days = 29
Avg consumption = 20.45 kWh/d

April 2012 (4/3-5/2/2012)
Total KWH = 609
# of Days = 29
Avg Consumption = 21.0 kWh/d
Savings versus 2011 = -2.7%

No...that's not a typo folks. I actually used nearly an indentical amount of power this year as last year. Seriously...what are the odds of that? I guess I'm consistent! My gut says that cold spell in April is probably to blame...for 2 days morning temperatures got down to the low 30s which required us to turn on the heat.

FYI, I'm sure you may have noticed that blog has some updates (size and data). I'm just getting it all setup for the eventually addition of the "Live Power Usage", per my previous post. We're almost there...we just need to get through a couple more kinks.

Publishing TED Data

Sorry I've been away.  We've been working hard on try to create a system to automatically download all my TED data into a Google document and then post it to my blog.  Cool stuff huh?  Below is an example of me trying it out...

Eventually I'll be creating some graphs and those will be posted hopefully in a sidebar.  So if you come back and you see some funky stuff...well...we're in beta testing, so bear with me, OK?

The April measurements will be coming out soon!  I don't think we did as well as last year due to that one very chilly week we had (we had freeze warnings!)

March Energy Bills

Last Months bills are in and the results are below:

March 2011
Energy Usage = 984 Kwh
33 Days
Usage= 29.8 Kwh/D

March 2012
Energy Usage= 704 Kwh
32 Days
Daily Usage = 22 Kwh/D
26.2% Reduction

Great, huh?  Even with the geothermal, we had a 26% reduction.  I'm Chalking that up to the unusually warm season we've had so far.   Next month will be interesting as we've needed to use the heat 2x (now 3 as my wife reaches for the thermostat...64 is Ok right?) due to the last 3 chilly nights (30 s!)

Solar Panels - Got a quote - Do I? Or Don't I?

OK...so this afternoon I met up with Greenspring Energy to discuss the idea of putting up solar panels on the roof.  I don't have much area...about 215 sf, by my estimate...so the system would not be large.

Anyhow, so this is the system sizing they came up with:

DC size:  2 kW
 AC/DC de-rating factor:  0.93
AC rating:  1.9 kW
Type of Panel:  Sunpower E20/327 panels
(E20 = 20.1% efficiency; 327W)
# of Panels (@~61.5" x 21.2"):  6

Expected annual output:  3194 kWh (based on PVwatts with an annual average solar rating of 5.07 kWh/m2/day).
Expected annual energy value:  $329 assuming 0.103/kWh
Estimated Price:  $12,262
Subtotal minus 30% federal and 35% state tax credits:  $4,293

Estimated ROI without any increase in dook Energy rates:  13 years
 Estimated ROI with a 5%/yr increase in dook Energy rates:  10.5 years

If I do the buy-all sell-all option, the ROI ends up being the same even at the higher $0.15/kWh due to the increase dook Energy monthly "facilities charge" of $16 vs the current $9/month.  Leave it to dook energy to spoil all the fun.  So, net metering would probably be the best option.

The system would produce roughly 28% of my annual power usage:

Feb 2011 - Feb 2012:  11,470 kWh or 947 kWh/month
Solar PV as % of Household usage:  3194/11470 = 27.8%

On some months the PV would account to roughly 54% of my usage (May-June) while during January it would only be 17% of my bill.

Overall...I'm not too thrilled about their ROI.  Having an ROI of 10-13 years is too high.  Plus, I know I won't get my state tax credits until at least 2014 because the State still owes me the second half of my geothermal tax credit.

What's interesting is that when I use the solar-estimator.org site, I get a 6 yr ROI.  I notice that the solar calculator includes the Duke Energy RECs ($82/yr) and the NC Greenpower incentive ($264/yr)....both of which are not included in Greenspring Energy's calculations.  The solar estimator also only has a 3.78% dook energy annaul inflation rate vs their 5%.   The ROI goes to 7 years if I set the inflation rate to zero and then set the electricity rate to 0.0929/kWh.  While it's not 1-2 years (like my latest mortgage Refinance)...6-7 years is still a pretty good ROI.

So...what do y'all think?  My gut says I should at least wait until Fall 2013 for the tax credits...that's assuming the tax credits survive the upcoming election...to minimize the amount of time I have to wait for the tax credit return.

Also...solar technology is evolving quickly.  New multi-junction concentrated solar panels are achieving 30-40% efficiencies: http://cleantechnica.com/2011/02/17/high-efficiency-solar-cells-getting-more-efficient-cheaper/

Who knows...in a year these bad-boys could be selling thus allowing me to get even more power from my small roof area (yes...most likely at a premium price...but if the ROI is right...)

March Bill ~40% reduction in energy use

OK OK OK....yes I've been slacking.  And by slacking...yeah, it's been a LOT.  There's no good excuse for me, so sorry! 

I will say that ever since we switched to e-billing, I don't get to see the bill when it comes...so I have to bug my wife to let me know what it says.  So there...ha!  I can somewhat blame my unresponsiveness on her, right?

We got March's bill on the 6th and here's the results:

March 2011 Bill - 953 kWh over 28 days or 34.04 kWh/d
March 2011 Natural Gas Bill- 24 CCF  over 28 days or 0.857 CCF/d -->converted--> 25.9 kWh/d
Total March 2011 = 59.91 kWh/d

March 2012 Bill = 1051 kWh over 29 days = 36.24 kWh/d
% Savings = 39.51%

Comparison to March 2010 (Townhome) = 71.10 kWh/day
% Savings = 49%

So the savings keep adding up.   Since March 2010 was when we first moved into our new home, the comparison against the Townhome is over.  On average the Geothermal system has reduced my energy consumption enough (in the 2700 sf single family house) such that our energy usage is ~16% less than the former 1300 sf townhouse.  That's pretty cool.

Below is a figure showing our home energy usage from when we moved in to date  (Note:  April 2012 is just an extrapolation from the TED data to date).  You can see that our energy usage used to varied greatly with the seasons especially in the summer and winter.  Afte we did all our housework and installed the Geothermal system our energy usage is significantly lower...one average 33%...and it would be higher except that during the spring and fall (like what we're doing now), we turn off our HVAC system because the house stays comfy day and night with simply opening up the windows. 

Money wise its not as significant thanks to the latest Duke Energy increase in rates.  But it could be worse, that's for sure.  Below is how our total energy bill has compared.  I like the fact that our bills are much more reasonable (again...the April Bill is just an extrapolation of the TED data).  Since installing the geothermal, our largest bill was the January bill (aka dated in January...but actually for December). 

I guess now the question is...what do I do next? 

I certainly do plan on installing a new HW heater in series with my existing to optimize the Geothermal dessuperheater.  Eventually I'm going to add in a Nyle Geyser ASHP to the new HW heater. 

And today, I'm meeting with Green Spring Energy to talk about solar panels.  That'll be a discussion on another post...maybe tomorrow?

February Bill - 64% reduction

We got the Duke Energy Bill for February a couple days ago...drum-roll please:

Feb 2011 Electricity Bill:  1967 kWh
Number of days:  28
Average:  70.25 kWh/d
Natural Gas Usage:  19 CCF (108,722 BTU/d) = 31.9 kWh/d
Total 2011 Usage:  102.11 kWh/d

Feb 2012 Electricity Bill:  1075 kWh/d
Number of days:  29
Average:  37.1 kWh/d
Savings = 63.7%

Comparison to the former townhome:  51.1% reduction

I'm not celebrating too much.  Last month was unusually warm here...not to say that we didn't have our cool nights...but still...some days were in the high 60s/low 70s.

Savings are savings, right?  I'll take it...