Building net-zero-energy home: need automation advice!

[energy_conscious]

Thanks.

Have you (or anyone) tried the enocean switches or sensors in a residential context?? How reliable are they, and how do they connect to home automation gateways?

We're also trying to future proof the house as much as possible, made the first floor handicap accessible, and are trying to set things up to accommodate future technologies or systems that aren't in our budget today. And we will have a website for the project!

As per above, our 1000/kWh budget for all energy use for the house is important, and all our lighting will be either florescent or LED. What I'm most worried about now is finding switches that are reliable and can dim the lights, be remotely controlled, don't use energy themselves, and are affordable...

 

[apostolakisl]

I see that as pretty much ruling out an always on computer. At 200 watts times 24 hours/day times 30 days per months that would be 15% of your budget. Even if you had a 100 watt computer that would still be 7%. And if you have 50 switches at 1 watt each that is 4%. The only way you are going to get this to work is with less than 100 watts total in your home automation setup and really more like 50 watts would be ideal.

 

[energy_conscious]

Yes - that's why I don't think I'd be able to use Lutron - after repeated attempts they haven't responded how much energy their repeaters and servers consume, but I fear it would be too much. However, Vera is ~5W and HomeTroller is ~10W, and those are viable. And I like the idea of the no-power enocean switches and sensors if they would work reliably in our setup...

 

[apostolakisl]

I have never heard of oceana home automation before so I don't know much about it. But any system that has switches with no vampire draw is going to have to be hard wired since nothing "listens" without consuming electricity. I would highly recommend you don't use any of the systems that run all of your loads to a central location where a switching box turns everything on/off. These are very proprietary, the companies are not diy friendly (pretty much diy impossible since they won't sell you anything), and once installed with drywall up you are stuck with it. There are some systems that run a signal wire (like cat5) to each gang box but otherwise wire the house like normal. I still thinks these switches have some vampire draw however and there is a lot of extra wiring that needs to be done. Plus, once the sheetrock goes up, it becomes very challenging to automate a gang box that originally you didn't' think you wanted to automate.

I would highly recommend you stick with systems that do not require any special hard wiring (Insteon and UPB). These systems work very well and can totally be removed/updated whatever. They are 100% diy friendly. Remember that 99.999999% of houses do not have special wiring and, even if every house built from today on had special wiring(which is not going to happen anyway), it would still be decades before the majority of people didn't have the "normal" wiring in their house. What this means is that there is a market for products that work with regular wires and there will continue to be for a very long time. So, in short, you will be able to maintain and upgrade your system without tearing out walls for the indefinite future. Plus, it would be good for resale not to have some system that only a handful of electricians can service.

 

[apostolakisl]

FYI. According to the ISY forum moderator, ISY unit uses less than 3 watts. That is very impressive considering what that unit is capable of doing.

 

[tmbrown97]

Lou - I've been seeing these EnOcean devices around for about a year or two I believe. The whole concept if you read about it is that the devices generate the electricity they need via a variety of methods; the switches get the burst of energy through the clicking action. Their motion sensors use tiny solar cells. There were a couple more in there too.

I didn't see nearly the number of options for dimmers and 3-way switches and all the nice things we've come to appreciate from a more established lighting protocol - but it looks like a good number of manufacturers have jumped onboard, including leviton and others. It may have potential; but only if they really pick up the pace to catch up with how for evolved ZWave and UPB are. Added benefit for them though is that they have a handful of relay switches that don't require neutrals - that could be big for people.

 

[apostolakisl]

I don't really get it. I downloaded the technical reference manual from leviton http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=26977&minisite=10025&ParSection=0&sitex=10025:22372:US for their line-up of enocean technology licensed devices.


I decided to start with the most basic item, a wall switch on page 13. If you read the spec sheet, it says it consumes something under 1/2 watt and that it has a range decrease if no neutral is present.

I find it very hard to believe that enough electricity can be generated by such low energy activities as pushing the rocker to power an rf signal that has a 900 foot range in the open or 150 feet in the house. What if the switch is in a dark room for a few days and nobody pushes it. How could it keep listening for rf signals without depleting any energy stores.

To me, this sounds too good to be true. Something must give. I would love to hear from someone who has actually installed this stuff. I also haven't come across how these switches would work with a home automation controller comparable to Home Seer or ISY.

 

[shern]

First poster but longtime reader on this site. Thought I'd throw my two cents in on the ZEH and lighting control.

My wife and I just finished our home June last year. We've gone half the way on a ZEH but not to the extreme that you are going. It's a story and a half home with 2500 sq. ft. conditioned downstairs and an unfinished attic with around 2000 aq ft. upstairs. We're conditioning the downstairs and maintaining the upstairs at an increased setpoint temperature. What I’ve seen is that the upstairs heat pump doesn't run during the winter but is used as a "buffer" from the hot sun during the summer. The home construction utilized 4-1/2" wall and 10-1/4" roof SIPS panels. The home is entire electric including well water. I work for a geothermal manufacturer so naturally installed a couple of our units. We live in the middle of the plains and constantly have 10+ mph winds and would love to install a wind turbine but with an electricity cost of $0.10kwH it doesn’t make economical sense.

What I can tell you from living in the home for a year is your goal of a ZEH you will really need to focus on other items besides hot water and space conditioning. Our base load for a couple months last fall (ie, very little space conditioning) with just the two of us, both working during the day was ~800kWh. This was the load from regular items such as oven, cooktop, lights, TV, electronics, refrigerator, freezer, washing machine and drier. As you can see, just basic appliances can push you almost to the 1000kWh/mo limit. I'm not saying that it can't be done, just very difficult. If we had any kids, as you mentioned, I imagine our base load would be higher yet. I'm really, really wanting to get a Brultech or equivalent to see what items I need to focus on to get the base load lower. You can also see this trend from some research homes done by ORNL at: www1.eere.energy.gov/femp/pdfs/tir_zeroenergyhouses.pdf.

Enough on that, now to your original question...lighting control. I installed all Levition Vizia and Vizia RF switches. After looking into all of the technologies it really came down to the look of the device and how they could match with the other switches and receptacles in the home. I'm not going to lie, they were expensive but I really like the look and have had not problems with them except a few glitches during initial setup. I'm running 24 different switches/controllers in critical locations mainly due to the cost of having them installed everywhere. I’m currently using ThinkEssentials to control the lights but am working on integrating them in with my Elk security system. I haven’t measured the vampire draw on these switches so I can’t comment on that aspect.

I agree with other posters that the ELK works great for security but it’s HA capability is limited. I haven't looked hard into Premise, Vera, or Homeseer to see how much better of an option they might be for HA than the ELK.

Also, if you are looking into lights I’m using some of the Cree LR6 LED’s and absolutely love them. They have dimmable version called the CR6 that you can get at Home Depot as well.

 

[tmbrown97]

Lou - the wired in switches will consume some power; it's the sensors like the motion sensors and handheld switches that generate their own power. Look at the early posting to the technology for information on how they harness power. The reality is they have motion sensors and remotes that don't hook to any power source and they do work... That said, it's expensive upfront, I can't find any good information about their dimmer capabilities; and I have yet to see a single home automation platform support it - so I think it has a long way to go to even be taken seriously. What would one more solar panel cost vs. spending roughly $50/device more? I wouldn't bother yet.

I'm most worried about now is finding switches that are reliable and can dim the lights, be remotely controlled, don't use energy themselves, and are affordable...

You should be worried - that's a pipe dream. Even a non automated dimmer switch with a remote will consume some amount of power. Either accept the power drain or give up on automated switches. I don't have my calcs in front of me but do the math - at .6 watts per switch, how many switches will you have, and how much does that add up to? Can you accept that or not?

 

[apostolakisl]

Yes, as I looked at more descriptions of these switches I came to the conclusion that their usefullness is in adding another switch without wiring, or having occupancy sensing lights. Personally, I don't want occupancy detection in my home. Sometimes you don't want the light to turn on.

They are very expensive. It is only cheap if you are looking at adding a switch without needing to add wires.

And, as you said, I don't find where any HA controller communicates with them.

I'll stick with my Insteon at $40 and .25 watts/switch along with my ISY at 2.5 watts.

And Elk M1G is very HA capable, but it isn't my favorite programming interface. The ISY interface is much better. Elk is a little short on memory too.

 

[BraveSirRobbin]

Cocooner Shern makes a great point. You should also concentrate on how you are going to monitor all this spiffy low energy consumption plans you have and see if it indeed is meeting your goals! Also consider as he stated in actually turning off all unused appliances with the HA technology you choose as well.

 

[apostolakisl]

I just looked at my most recent electric bill. I used 1800kwh on a 6000sf all electric house (except cooktop/hotwater). And the bill was only $161.00 or 8.8 cents/kwh so I don't understand what California is up to. Last month the AC was on but it wasn't pushed real hard since most days were in the 80's and a number of days were only in the 70's. My average consumption appears to be something just shy of 3000kwh/mo with the worst month last year being August at 4100 (it was 105 degrees every day). I do have the a 2 year old highest end carrier infinity heat pump (I think seer 19 but I forget). I also have spray in foam and high end Pella windows. Plus an 800 foot well that watered for several hours every other day. I should replace more of my incandescent lights but I just am not satisfied with the current alternatives, especially on chandaliers. I'm waiting for the led's to take that next step.

 

[davidfay999]

Lou Apo: You're doing pretty well on energy consumption. The (very rough) average use of residential energy in the US is 50,000 btu/year/ft2 of conditioned space. If you're using 3000 kWh per month for 6000 ft2, that's (3000 kWh/month x 12 months/year x 3412 btu/kWh) / 6000 ft2 = 20,472 btu/year/ft2

That shows that good insulation and high efficiency equipment really make a difference.

For those wondering what's up with California electricity rates: it's a conscious policy designed to get people to reduce their residential energy usage. And, yes, it is social engineering, intended to help us avoid the armageddon of climate change.

For those that get electricity at 8 cents/kWh (I pay 13.5 cents/kWh here in MA), there's a good chance that is going to change. Electricity rates that low usually mean your utility is buying electricity produced by burning cheap coal. Almost everyone agrees that the only way to seriously reduce greenhouse gas emissions is to stop burning coal. The alternatives are all more expensive.

Shern: I don't think getting under 1000 kWh/month for electricity baseload is "very difficult". My wife and I averaged 385 kWh/month last year in a 2200 ft2 house. Having a good real-time electricity monitor really helps, as you suggest. II'd love to post the URL for mine, but as a new contributor, I am not allowed to post links. And careful choice of appliances is very important (e.g., avoid a gas oven ignited by a glow bar).

David

 

[Ira]

...

For those that get electricity at 8 cents/kWh (I pay 13.5 cents/kWh here in MA), there's a good chance that is going to change. Electricity rates that low usually mean your utility is buying electricity produced by burning cheap coal. Almost everyone agrees that the only way to seriously reduce greenhouse gas emissions is to stop burning coal. The alternatives are all more expensive.

...
David

I renewed my 12-month contract last week. It's for 100% renewable source electricity. I assume it is wind generated. The price was $08.7/kWh at 1000kWh. If I had not opted for 100% renewable, I could have gotten $08.2 from the same provider.

 

[tmbrown97]

Just for comparison... this is a 4K sq ft. home in northern california (we have hot summers in the 110+ range) - 5yr old home with decent appliances; gas hot water, conventional A/C with Gas furnace and the crappiest dual-pane windows in existence... We bought at the tail end of June last year (moved in mid july) and this is our usage and cost since. In Jan/Feb, I'd be willing to bet our gas fireplace accounts for much of the gas consumption - my wife loves having it on.