My IotaWatt installation.

[Shimmy]

With 4 units however the higher price of iotawatt is hard for me to justify. If you only need 1 unit, the iotawatt seems much better.

I started with one and added as time went on. My main panel was the first one, which got the PV, the three mini-splits, the incoming utility, and the two sub panels. It gave me a lot of useful information that helped me save a bit of money (mostly lighting retrofits that weren't rocket science, but now easy to quantify the savings). Then I added the one on the kitchen sub panel, which gave me information I needed to replace door gaskets and clean the condenser on the fridge which saved me about 1kWh/day. Then I could easily justify adding the one on the laundry sub-panel which got me consumption data for the EV charger and my office... which was a huge energy hog.

I haven't figured out any way to save energy in my office, at least not in a meaningful way without reducing functionality... but the information I got from the monitoring system at least gives me good data on what I can do to improve backup power options for it.

I've been a fan of branch circuit monitoring for a long time. The various types of graphs that @MurphyGuy used are exactly what I started out with to evaluate my system and various loads. It does get a bit addictive, and there are still a few circuits I want to meter that I don't have yet.

 

[svetz]

Tell me more. Higher SEER? Every mini I look at online seems to be north of 18 SEER with some up in the mid 20's or more. So your unit isn't just an air conditioner, it's also a heat pump?

Are you looking at SEER or SEER2 numbers? The country is now divided into 3 parts, each has their own minumum standard.
Ratings dropped a lot with the new standard. EnergyStar has ratings for most models.

Linking @Supervstech for the really big guns.

 

[MurphyGuy]

Are you looking at SEER or SEER2 numbers? The country is now divided into 3 parts, each has their own minumum standard.
Ratings dropped a lot with the new standard. EnergyStar has ratings for most models.

I'm not knowledgeable enough on how consumer rated appliances measure up in that way. I just know that the higher the SEER rating, the less energy it uses and the more it costs.

Linking @Supervstech for the really big guns.

Huh? I don't understand this at all.

 

[svetz]

...Huh? I don't understand this at all....

He's a pro at AC, anything I flubbed up he can set straight ; -)

 

[Supervstech]

Are you looking at SEER or SEER2 numbers? The country is now divided into 3 parts, each has their own minumum standard.
Ratings dropped a lot with the new standard. EnergyStar has ratings for most models.

Linking @Supervstech for the really big guns.

SEER was an easy metric for many to get a grasp on manipulated efficiencies.

It was geared towards specific conditions to make equipment appear efficient.

SEER2 is a broader efficiency standard that should get closer to real world use consumption.

All those 20+ SEER units likely are going to struggle to show over 17SEER2

 

[MurphyGuy]

SEER was an easy metric for many to get a grasp on manipulated efficiencies.

It was geared towards specific conditions to make equipment appear efficient.

SEER2 is a broader efficiency standard that should get closer to real world use consumption.

All those 20+ SEER units likely are going to struggle to show over 17SEER2

What do you recommend for a unit? I think our current system is 2.5 Tons and it has always struggled when temps go above 90°.

 

[Supervstech]

What do you recommend for a unit? I think our current system is 2.5 Tons and it has always struggled when temps go above 90°.

Id need to perform a load calculation and blower door test on your home before recommending any equipment changes.
You might just need attic ventilation, or insulation improvements.

 

[MurphyGuy]

Id need to perform a load calculation and blower door test on your home before recommending any equipment changes.
You might just need attic ventilation, or insulation improvements.

Can you just assume I need 2.5 Tons of cooling capacity?

What I'm looking for is a recommendation on brand and SEER rating vs Cost. I'd probably install it myself and I have a guy who can take care of charging it for me. He'd probably be the one I go through to purchase it as well since he works for a large local place and does this for a living.

He used to rent a condo from me.

 

[Supervstech]

Can you just assume I need 2.5 Tons of cooling capacity?

What I'm looking for is a recommendation on brand and SEER rating vs Cost. I'd probably install it myself and I have a guy who can take care of charging it for me. He'd probably be the one I go through to purchase it as well since he works for a large local place and does this for a living.

He used to rent a condo from me.

If 2.5 ton unit you have now struggles at 90, and you are increasing the efficiency, a real load calc could point you as to why it struggles.
Keep in mind, higher efficiency equipment often has a different sensible vs. Latent capacity.
Thats why a load calc with a manual S equipment evaluation is a good idea.

To keep it from struggling, attic sealing with deck insulation, and a dehumidifyer may keep your current system from struggling.

Or proper roof ventilation with air sealing.

Where the ductwork is makes a difference as well.

Also duct leakage makes a huge difference in a home.

 

[zephyranthes]

Tell me more. Higher SEER? Every mini I look at online seems to be north of 18 SEER with some up in the mid 20's or more. So your unit isn't just an air conditioner, it's also a heat pump?

Yes it’s a heat pump. Put it in the room to hunker down in and run on reduced electric when the grid goes out. Keep us cool or warm no matter what.

I was looking at the LG

LA090HYV3​

Also I had it swapped. My current one only heats down to 17 F outside temp but this one heats down to -13F outside temp.

 

[pmccut]

I've been using IotaWatt for a long time too. Had one running for a couple years, added a second one about a year ago to monitor more circuits. I dump all the data into prometheus so I can use grafana. I'm not a big fan of influxdb so I just modified the code and re-flashed the units to work with prometheus.

For home assistant I just use the built-in plug that scrapes from one of the two units (the first one monitors the main lugs).

 

[OffGridInTheCity]

I just got my IotaWatt installed and integrated into my system. It's exactly what I've been looking for for quite a while. My goal is to monitor/record the output of my off-grid inverters - e.g. 2 x AIMs 12,000w inverters.

Here's a snap of VRef and power being consumed on each 120v leg (Red wire and Black wire) from one of my AIMS inverters.


A simple IotaWatt query ( https://docs.iotawatt.com/en/master/query.html ) like this: http://192.168.2.xxx/query?select=
[time.local,VRef,I2Black.Watts,I2Red.Watts]&begin=2023-01-31T21:14:00&end=s&limit=360&group=5s&missing=zero&format=csv returns 5sec granularity records in csv format starting at 2023-01-31 at 9:14pm with the Inputs values illustrated in the pic above - e.g. VRef, I2Black, I2Red...
2023-01-31T21:14:00, 115.5, 431, 1118.3
2023-01-31T21:14:05, 115.3, 527.2, 1121.4
2023-01-31T21:14:10, 115.5, 437.1, 1136.1
2023-01-31T21:14:15, 115.6, 413.6, 1151.1
2023-01-31T21:14:20, 115.3, 414.3, 1138.6
....

which is straight-forward to insert into a SQL Server database table....

.....

And a simple SQL query summarizes 5 second interval data into Kwhs over a range of time....
select isnull((sum(I1Red) / 1000) * 5 / 3600, 0) as I1RedKwh
, isnull((sum(I1Black) / 1000) * 5 / 3600, 0) as I1BlackKwh
, isnull((sum(I2Red) / 1000) * 5 / 3600, 0) as I2Redkwhs
, isnull((sum(I2Black) / 1000) * 5 / 3600, 0) as I2BlackKwh
, isnull((sum(I1Red) / 1000) * 5 / 3600, 0)
+ isnull((sum(I1Black) / 1000) * 5 / 3600, 0)
+ isnull((sum(I2Red) / 1000) * 5 / 3600, 0)
+ isnull((sum(I2Black) / 1000) * 5 / 3600, 0) as TotalKwh
from iotawatt
where DataDate >= '2023-01-29 06:00' and DataDate < '2023-01-30 06:00'


This lets me integrate the metrics I'm interested in to my 'live' dashboard ...

and the raw data is in the DB for future queries. At 5s intervals, I estimate about 1.2GB / year of database file space.

One issue (for me) with IotaWatt is the Voltage Reference requirement. When the off-grid inverters are off (low battery) the VRef goes to 0 and the unit doesn't like this. However, it resumes operations when the Inverter comes on. I get the impression it goes into a 0 value induced (infinite) loop which starves the processor until the VRef comes back. This causes issues such as the Logs dismount. A recent update to ALPHA 02_08_02 firmware might help this according to the IotaWatt forum. But even in the VRef = 0 case, the query (above) returns 0 values so it works for me.

Another issue is multiple voltage references. I want to record individual power on each 120v leg of both of my inverters. To do this 'best', one would need 4 x voltage references - one for each 120v leg. But it appears that having 1 voltage ref per inverter gets me close enough. I learned I can add a 2nd (and 3rd) voltage reference on inputs 13 and 14. Using 13 as a voltage ref will let me get reasonable power data from a 2nd inverter so I can track all 4 x 120v legs from both inverters. The 3rd voltage ref - I might use use to track the power coming in from a generator (to charge the batteries).

I totally Love this unit so far as all data is local, simple to access! One can upload to a local InfluxDB for amazing graphs - which was relatively simple to setup and all local - but I don't need this.

P.S. Shoutout to @MurphyGuy for pointing me here on a different thread and for quick responses on the IotaWatt forum @overeasy to get me oriented with my VRef issue

 

[Shimmy]

...which is straight-forward to insert into a SQL Server database table....

FWIW, a true time series database like Influx can make things easier than using SQL. The native uploaders also simplify the process and allow for good failure mode recovery.

But, if you are happy with your setup no sense in changing.

The IoTaWatt seems to natively track Watts and VA rather than amps, which might explain your vref issue. It leads to a few accuracy limitations, but generally is a logical choice.

 

[OffGridInTheCity]

FWIW, a true time series database like Influx can make things easier than using SQL. The native uploaders also simplify the process and allow for good failure mode recovery.

Ha... Early in my career I moved to the San Francisco bay area and got a job at Sybase in Emeryville. This is the company that created Sybase SQL Server and gave the code to Microsoft for collaboration (in early years to help with sales) who then expanded it to the MS SQL Server product in use today. Spent significant time in my professional career working with SQL and could do nothing but use a SQL Server!

 

[pmccut]

I think the biggest reason to use a time-series DB is just the easy integration with grafana. You can just use SQL as a data source of course, but where's the fun in that...

I had a similar setup before scraping the page but it's super easy to change their open source FW to fit your needs exactly. That's totally the reason to go with IotaWatt IMO. Good work!

 

[BlueMarblePA]

I just received PTO two weeks ago, and I installed Iotawatt the day it was delivered to my door -- yesterday! I can't wait to delve into the numbers like the rest of the folks here! I may need some help with some of the CTs, though. Mains and Solar seem okay, but my electric panel is a mess (I moved in five years ago, and I can't believe what a mess it is in there!)