The greenhouse effect is well known to anyone who has entered his or her greenhouse (or car for that matter) amidst a blazing sun: interiors heat up considerably more than their exterior surroundings. The reason being that the energy of the sun’s rays heats the soil and plants within the greenhouse – plus the structure of the greenhouse itself – but fails to escape due to the heat-retaining design of the greenhouse. In this tutorial, we’ll show you exactly how to automatically cool a greenhouse with Eve Degree and a fan connected to Eve Energy. The same method can be used to circumvent the buildup of heat in attic apartments, sheds, or any other indoor space that is susceptible to heat retention.
Air exchange by ventilation
What is desired in a greenhouse during spring and autumn can be deadly for plants during summer, a period in which solar radiation exacerbates heat levels. Temperatures in excess of 30 degrees (86 F) damage or even kill most plants and, in a greenhouse, levels can reach upwards of 50 degrees (120 F). Usually, greenhouses equipped with windows and roof vents facilitate adequate ventilation when open. And plants save themselves from overheating by means of transpiration. However, on sunny days without wind, open windows and vents do little to facilitate air circulation. That’s why a fan, mounted one to two meters (3-6 ft.) from a roof vent, can mean the difference between luscious leaves and brittle twigs.
Measure and regulate temperature
With Eve Degree, we can measure the actual temperature in a greenhouse and keep track of fluctuating levels with the Eve app (the same can be done with Eve Room and Eve Weather). Now, with the help of two rules and two scenes, we can have Eve Energy automatically switch on a ventilator when Eve Degree senses a temperature in excess of 28 degrees (83.5 F), and switch it off automatically when the temperature drops below 23 degrees (73 F).
Two scenes for two rules
As noted, you need two rules with two scenes. For Eve Energy, create and set the scenes Fan On (activated by Power > On) and Fan Off (Power > Off). Test the two scenes manually to ensure that they work.
Rule for activating the Fan
To create the first rule, choose Scenes > Rules > Add rule. Select Add Value Trigger and Type > Temperature. Then activate Eve Degree. Under Value Trigger you will find Any and Specific. The easiest way is to set Specific, then More Than, and specify a value for the temperature, which in this tutorial is 28 degrees (83.5 F). Eve automatically creates a trigger with the value, Any, and the required value condition, which in this case is Temperature more than 28 degrees. Finally, select the scene, Fan On, and set a name for the rule, such as Ventilation On.
This workaround via a trigger (any change of the temperature value) with the value condition (temperature more than 28 degrees) is necessary in Eve because HomeKit currently does not allow value triggering with higher-/lower-than values in iOS 10. In the Apple Home app, such a rule cannot be applied at all. Eve makes it possible.
Rule for deactivating the fan
To ensure that the fan does not cool your greenhouse excessively, you need a second rule to deactivate it once the temperature drops to 23 degrees. This works analog to the rule for activating, in this case with Value > Specific, the condition Less than 23 Degrees, and the scene Fan Off.
Not only for your greenhouse
Anyone living in an insufficiently insulated attic apartment will also benefit from a similar setup, where windows are kept open or ajar, and a fan automatically facilitates air exchange for the purpose of cooling.
TIP: You can combine this automated setup with a humidifier to further regulate your indoor climate.
NOTE: Mobile air conditioning systems are not suitable for this setup as they require well over 3 kilowatts or power, which is beyond the load capacity of Eve Energy.
How it works
Eve Degree detects a (any) value change in temperature (in 1 degree steps) and notifies your iOS device or fourth-generation Apple TV. Your iOS device or Apple TV registers the notification and connects to Eve Degree via end-to-end encryption to ascertain the value change. Your iOS device or Apple TV then checks the value change to see if it affects a created rule with a condition (in our example, temperature exceeds 83 F). If this is the case, the corresponding scene – Fan On – is activated.
Still no HomeKit Notifications
HomeKit / iOS does not (yet) support notifications for temperature (nor humidity and VOC concentration), so you won’t receive a message on your iPhone from the Home app when your specified temperature is exceeded. We hope Apple will fix this soon. Until then, a workaround can be achieved by creating an additional scene that switches on a lamp connected to Eve Energy, or a Hue lamp, when your specified temperature is exceeded.
Will this method and the humidifier setting from your previous post also work with Eve Room and Eve Weather?
Do you have a comparison table that compares the Room, Weather, and Degree products?
Thanks!
Hi Bruce! Yes, the setting will also work with Eve Weather and Eve Room. All three accessories feature measuring of temperature and humidity. Eve Weather and Eve Degree measure air pressure, Eve Room air quality (VOC). Best regards, volker
Good afternoon,
Earlier in the year I had asked when the eve energy (with wireless) was scheduled to be released (January after the CEs).
I was told that you had no idea yet.
However six months have passed, I have an interest and urgency in acquiring several products.
I’m thinking of change to the competition, which already offers these outlets with wireless (like for exemple tplink).
Homekit will be more flexible so that more players will enter the market,I like your products but you are taking a lot of time to give news about eve energy wireless and eve extend.
I would like to invest in a system centered on a single company just like I did in the case of lighting with the Philips Hue, but if you do not have any availability information I will seriously consider going to another alternative.
So can you please give me an idea if and when there will be news in the eve energy (with wireless) plugs?
Thanks
Fernando
Hi Fernando! You are probably talking about a WLAN version right? I can’t comment on future products or developments, sorry. One comment: iOS 11 will improve a lot in terms of HomeKit, Apple announced it during WWDC. Best regards, volker
Thanks for your answer.
Yes probably yes …. I thought that is going to be the same version but also with wireless but it makes sense (because of HomeKit) that probably are going to be a WLAN dedicated version.
Anyway thanks for your answer , I’m still waiting …. To be honest, not know for how long but still waiting for that version 🙂
Thanks
Fernando
Hello,
So if I got this right, the Eve Degree or Eve Room will notify my Apple TV about the change in temperature but only every 1 degree? So if the current temperature is 20.9 the Apple TV will be notified only at 19.9 or 19? I’m trying to understand how the trigger works as my Eve based system is not working properly. The rules don’t get activated at all. What about a time based condition? If the temperature triggered outside the time constrain it will trigger again at the next degree down? That means staring from my example it will be 18 degrees? Thank you!
Hi Mihai! If you set a rule in Eve with “Temperature change any” and condition “< 20 degrees" the trigger will be fired once the temperatur falls below 20 degrees, like 19,5. It will be triggered every time the temperature falls below, so again at 18 degrees, 17... Best regards, volker
Is this a limitation from HomeKit? Because if, in my case, the trigger happens just before the time condition, then the next trigger will activate at the next 1.5 degree , in the worst case, which may take another hour or two. One workaround is to disable the time condition but that will heat up the rooms even no one is there. I use an Eve Degree and an Eve Energy to control a pump for underfloor heating and I need the time condition as it takes about one hour for the heat to kick in.
Hi Mihai! What kind of time condition are you using? Best regards, volker
Is it possible with Eve Degree to define automatizations from Home App and not only from Eve app?
I can’t do it whereas with other products like Eve Energy, Eve Door I can. It’s an important issue.
Hi Carles! Using Eve Degree for automations, you have to use Eve, Home won’t do it as of today, sorry. Best regards, volker
I have a problem: in the trigger section I cannot set the temperature to ANY but only enables me to choose a specific temperature…
Hi Niccolò! That’s correct. This changed in Eve to avoid the triggering at any 1 degree step. Best regards, volker
Hi
I can’t get my rules working. I follow instructions for my fan & set fan on for T>=23 et fan off when T<=22 degrees. But it is not working. Manuelly it woks but not schelude with a trigger. Am I wrong some where?
Hi nikolo! You are using two rules, right? You need one for turning on and one for turning off the fan. Best regards, volker
Hi Volker. Yes I’ve made two distinctive rules. One for having the fan on and one for having the fan off. each one works individually. this is why I don’t get it.
my rule is
if T>=23° (trigger value & conditions) then switch on fan
if T= ou <=
I s there any way to send you as private message screenshots of each step so that u can see?
Hi nikolo! Please send me screenshots, could help to find out what’s going on. Please send to volker(at)elgato(dot)com. Best regards, volker
Hi. as Nikolo, I can’t get my rules working (last update of Eve on the last update of IOS)
Eve Degree doesn’t seem to act as a trigger.
Hi Yves! I am using Eve Degrees temperature as a trigger without any problem. Would you mind sending me screenshots of your rules to volker (at) elgato (dot) com? Best regards, volker