Automating Windows with Solar Smart Window Operators

Four years ago, we began a journey to create as close to a net zero operation as possible at Cinevate. We purchased an empty warehouse, gutted it, and installed new mechanical, electrical and serious envelope efficiency updates. It was also windowless, so we did solar modeling to maximize interior natural light, and installed various features, like a central clerestory to bring in light, and help with natural convective cooling.

The building was missing essential automation components which is where the Vera Edge, EVL4 (for security system integration), and nine Ecobee3 thermostats came in over the last few months. Vera's free security system and Ecobee plugins have worked flawlessly for us on the Vera Edge. We've dropped our natural gas use for heating 25%, and electrical costs another 12%, from levels already less than 50% of what a typical 9000 sq/ft building would use.

Here a few related reviews of HVAC projects in the building:

Nine Ecobee 3 Wifi thermostats in a net zero(ish) building.

Smarter HRV control using CO2 sensors

The issue with a very efficient building is that once temps start hitting 55F outside, we need to think about cooling. We try and stay off AC as much as possible, so natural cooling becomes important. Opening main floor windows turns off the Ecobee3 cooling modes, based on triggers read from the window security sensors, controlled by the Vera Edge controller.

We've been using a very cool solution for the clerestory windows using Solar Smart Window Openers. These devices are solar charged, have a wireless remote and can be controlled by temperature levels programmed on the wireless remote. Windows can be zoned in up to 9 groups of nine windows each. The new models include a rain sensor so you can attach them easily to skylights etc. If your windows or skylights use manual cranks, you remove these and replace with the opener unit. It uses a chain drive to push the windows in or out...up to 60lbs of load. Because they are solar charged and wireless, retrofitting them means no wires to run!

I've been using two of them for the last four years with zero problems in our clerestory to make use of convective cooling. The on board lithium cell has kept itself charged up, and the windows have required zero service since installation. You can zone windows and therefore control them independently or in any groups you desire.



This is what's in the box.



This crank will be removed and replaced by the Solar Smart operator unit.



Connections for the included solar panel and rain sensor.



An end cap hides the replaceable lithium power pack, and connection block.



You can check on the Solar Smart Opener lithium onboard battery level, solar charging rate, and remote battery level of any of the operators.

This the current charge rate (from the plug in transformer to top up the cells).



Remote battery status.



The lithium on-board battery level, just installed. Once charged, the solar panel tends to keep the lithium cells at 100%.





This is the clererstory we added in to the new office space. We modified a few trusses and extended the roof to create this south facing feature..my favorite in the building.

The Solar Smart Window Openers are used to operate these windows.



We've been using the temperature driven open and close feature present in the wireless remote units. You can set up the remote for example to open the window at 75 F, and they automatically close at 5 degrees cooler (70 F in this case). The temp sensor is in the remote itself. This however may not be ideal when using AC, or when outside temps are much higher. I spoke with the company 4 yrs back about this and noticed recently that they engineered a solution, a new remote, pretty much designed to integrate automation. This remote looks very much like the standard Solar Smart wireless remote, but it requires 9V power (they provide a plug in transformer). I have the ECI remote set up as a "slave" remote leaving a handheld wireless unit that can be used anywhere to open/close the windows.



I ordered up two more Solar Smart window operators after testing the effectiveness of night time pre-cooling of our building, about 9000 sq/ft. Pre-cooling dramatically drops our AC requirements. Now that the building has a Vera Edge automation controller ($129!), and integrates both security and Ecobee 3 stats (nine of them) I can finally make this process quite intelligent, and completely automated. In early manual control tests I froze the staff in early mornings by going too far with the night cooling.


The board below is installed in our equipment room and to control both our HRV, and the window operators. The LFM20 relay on the left allows control of our commercial Venmar HRV ventilator located right above it. It's a simple Zwave isolated relay. The MimoLight units are also relays. One is used to open the windows, the other to close them. Each MimoLite has a signal input so I'm using this to indicate the windows current state (open or closed). Mimolites are often used to control garage doors. The ECI remote for the windows uses simple dry contacts (open/close) to send wireless commands to the windows. Fortrezz has a new product, the Mimo which is not available yet, but has dual relays..perfect for this job.



This Leviton Z-wave switch allows both manual and automated control of our workshop exhaust fan. It moves 1500 CFM or so, and works well when run at night to force cool air through the building.


This is the fan, normally used to depressurize our work room. In winter, a removable door on the inside cuts heat loss when not in use.


The end result of all of this is the ability to open windows, run the building fan, run the HRV, run any of the air handler fans (connected to Ecobee stats) and control them via the temperatures indicated at the 15 or so Ecobee3 temperature sensors at night when temps here are almost always below 68F. It sounds complicated, but really it's pretty simple. The brains behind this is a tiny Vera Edge controller which uses a Zwave wireless network to talk to all of the various bits.

Re: Automating Windows with Solar Smart Window Operator

In case you are planning to automate the windows beyond the options present in the wireless remotes, here are few notes with respect to using a Vera controller and MimoLite Zwave relays to control them.

I was stumped on a few of these so had to make a few calls. Remember that these operators would work pretty much on any crank out skylight or windows. I've removed the window manual cranks, and installed the Solar Smart openers in their place.

Step one is to install the free Mimo plugin on your Vera box:

Go to Apps -> Install Apps
• Login if needed
• Search for "MIMOlite" and install it
• After the plugin is installed a new generic device will be installed

You can go ahead and include the MimoLite Zwave devices to your Vera hub now, adding them as a "Generic Device". Then fire up the plugin and enter the MimoLite device ID's. You can find the device IDs by checking the MimoLite (will show up as an On/Off switch) devices under the "Advanced" tab. The device ID on UI7 will show up at the top of the screen. Once you enter the device IDs into the plugin, (save, and wait for a few minutes) it will create child devices as shown below. The extra child devices monitor the Signal Input on the MimoLite relay...this is what makes the MimoLite as versatile as it is. Many use this input on a garage door sensor for example so you know when it is closed or open.





These parameters configure the MimoLite relays to act as momentary switches, staying open for .5 seconds. The ECI Solar Smart window remote in turn needs its dry contacts operated in this manner to open and close the windows. By default the MimoLite relays "latch" on or off...and this won't work for garage doors, the ECI remote etc. Mimolites are often used to automate garage doors.

Impressive use of technology all around. Nice job.

DC

Thanks DC I still find it surprising that these window openers don't get more attention.

I did a less intense treatment at home using Smarthings with ZigBee LED bulbs and a few motion sensors and cut 38% from our hydro bill just focusing on lighting. Family of four, zero behavior changes. Seems like low hanging fruit in terms of efficiency

Do they make a automatic closer for horizontal sliding windows?

That's a good question. I'll email Jim at Solar Smart and find out.

Mine isn't solar related but I wanted to close the window before commuting hours

Denwood said:

Thanks DC I still find it surprising that these window openers don't get more attention.

Click to expand...

That's because even the manually controlled operators are expensive. If you need them, you need them, but schools and the like have been getting by just fine with extension cranks.

PoorOwner said:

Do they make a automatic closer for horizontal sliding windows?

Click to expand...

By the time you get something to work properly you will have spent enough money to install an awning or hopper window and place a remote operator on it. Remote operators use a motor and gear reduction to turn the operator stem. It's almost as easy as clipping the thing on. But, you need power to that and that's another main reason more aren't in use because no one thought to run a circuit to each window location when the walls were open.

BTDT.

Zeke, tha is for those comments . The wiring issue was exactly why I chose the Solar Smart product. Other than mounting the small solar panel and connecting it, there is no wiring for either power or control. Other than replacing the remote's AA batteries once a year, they have required zero attention in four years of use.

It was also important that they open and close based on temperature. Now that I have the ECI remote, we can be smarter yet with respect to co-ordinating with our building night cooling strategy. Automating their operation is the key to efficiency.

Wonder how long it'll take you to get a return on your investment, rather than just as close to zero for your bills as possible.

TK, there are two approaches to that question. We already have reduced our operating costs vs a similar building to the tune of about $10 000/yr savings. Hydro rates here jumped 25% (peak) in January. The larger issue is what's happening globally, in which case the expenditure with respect to the big picture is not so much The contribution I have to make is to present the tech, provide some expense feedback, and be a good example for my kids, and work team

We're talking about a 9000 sq/ft space with 6 zones, 5 AC compressors and 1 mini split. The savings pile up quick.

We managed a surprising 38% reduction in average hydro use at home this month (using a comparative 2 month average), with zero behavioral changes. The focus there was just turning lights, and other consumers off when not in use.

I've always thought it would be nice to integrate automatic window control into a climate system. Ideally something would monitor outside conditions for temperature, wind, humidity, etc and appropriately open/close windows and turn hvac on/off automatically when it makes sense. So when it cools in the evening, switch off the AC and open the windows automatically but not if it's too humid still for example.

Looks like you're fairly close to that sort of setup, but just not quite as slick/integrated as the system could be (ie you had to piece this together).

ItsNemo, I agree completely. That said, the Ecobee 3 thermostats are capable of managing "free cooling" which runs a ventilator based on inside/outside temps and humidity. The stat fires up the AC only when the free cooling can't keep up.

At least for now, you pretty much need an automation controller to do this. The nice thing there is that a Vera Edge hub is $129, and you can mange a lot more than HVAC with it.

Night cooling with window control and building automation

Here's an update of how well the automated windows and night cooling is working. Basically I have been working with a plugin called "PLEG" on the Vera automation hub to manage when the windows should be open or closed, and when the night cooling routine should run.

Basically I've found that these variables work best to decide when to open or close the windows, as well as when (or not) to run the night cooling routines.

1. Ecobee3 thermostat current set point (target temp) vs outside temp.
2. The next day forecast high temperature
3. Whether the system is in heat or cool mode
4. The difference between current inside temperature and outside temp.

PLEG lets you create logic using these variables as well as do some pretty impressive control without learning complex code.

We managed a drop from 24.5C to 19.5C (about 10 degrees F) over 7 hours controlling one exhaust fan and the windows. The space cooled is about 7000 sq/ft...so a large area. The graphs below from one of the Ecobee3 stats shows the drop from 11pm, to 6am...when night cooling is scheduled to start and stop. Night cooling will stop before 6am if the temps reach their targets early.





A few of the PLEG pages from the VERA automation hub. It looks complicated, but really it's pretty straightforward. You define various inputs and schedules as shown in the first screen grab. In screen grab 2, the four conditions are either true or false. Each has a corresponding action when the statement becomes true...open the windows, close the windows, fire up night cooling, and stop night cooling.

To simplify things a bit, the night cooling ON logic really only checks two things. Are the windows open? Is the time between 11pm and 6am? Night cooling OFF checks only two things. Did the windows close? Is it 6am? In turn, the windows open or close logic looks at the various inputs and setpoints to make sure windows are open or closed based on how the inside and outside temps are tracking to each other. The challenge comes in that while we want free cooling when outside temps can provide this, we also want to make sure windows are closed when outside temps rise, and AC is called for.

If anyone is interested in more details, PM and I'll be happy to share whatever I can. The night cool strategy lets us stay off AC until 1 or 2pm in the building...so definitely works.

Wow, that's really cool, Dennis! And no pun intended. As you might guess, this project speaks to me.

I didn't quite fully grasp the system you were describing when we chatted about it in my workshop build thread -- I understood, but perhaps didn't really appreciate the scope of the project. Now that I see a comprehensive description of it, I'm even more impressed.

Having done something similar (though MUCH smaller scale) in my workshop, I've had it in the back of my head to do some low-impact climate automation in the house. The above write-up gives me both inspiration and a couple of solid ideas. Thank you for that.

Jess, the system continues to work very nicely. I've added a few more bits in there integrating the security system (simple EVL4 interface) with the Vera box. This puts the Ecobee3 stats into "away" mode when relevant zones are armed, and also turns AC off on the main floor if any window is opened...in which case the building cools convectively.

Arm/disarm events also cut power to all of the non-essential printers, monitors etc. which cut nearly 800 watts of parasitic drain. That and a full lighting update to 4" LED (about 300 lamps) have cut our peak power use over 30%.