Electrical Usage Puzzle in Gardner, MA

[sloeffle]

And no to the Kids and Cryptomining! They actually live nearby(age 34-special need twins). Son only stops in when there is food offered and daughter stops in too much!

I LOL'd too hard at that.

Great thread BTW, I'm learning a lot. I'm probably going to order a couple ( two panels in my house ) Emporia's myself.

 

[Potluck_Crew]

So you can see that the TC shows heat produced so at 45 dedgres wet bulb temp outside you and get 22.2 k btus (at 70 degrees inside temp) consuming 1.6 kw. At 5 degrees wet bulb you get half of that 10.3 k btus using 0.87 kw. I’m not sure why they use wet bulb outside.

With out any frost comment I assume is meaning no ice on the outside coil causing the unit to defrost.

And you said you have 5 of those 1.5 ton units? Even at at 15 degrees you have over 60,000 btus of heating capacity. And could consume 6kw. Now they all might not runn at the same time or at full output.


Here is a similar chart for my unit. Outdoor temps on the left column indoor return temp is along the top.

View attachment 291397

We have two of that size, and one smaller. Total of 6 cassettes inside.

Thanks for the explanation. I am beginning to grasp it.

 

[woodgeek]

The choice of wet-bulb outside is bc of condensation/frosting. Under dry conditions, the outdoor coil runs a few degrees cooler than the outdoor air (dry-bulb) temp. If its humid outside, such that condensation forms, the outdoor coil runs warmer, at the wet-bulb temp, rather than the dry-bulb temp - Delta T. With the heat of condensation contributing heat to the coil.

That is, my HP puts out MORE BTUs at 45°F when its raining than when its sunny. Bc when its raining, the outdoor coil is at 45°F (wet-bulb), whereas when its sunny, it is probably more like 38-40°F (dry-bulb-5-7°F). I can tell by measuring the temp of the air coming out of the registers.

 

[Potluck_Crew]

The choice of wet-bulb outside is bc of condensation/frosting. Under dry conditions, the outdoor coil runs a few degrees cooler than the outdoor air (dry-bulb) temp. If its humid outside, such that condensation forms, the outdoor coil runs warmer, at the wet-bulb temp, rather than the dry-bulb temp - Delta T. With the heat of condensation contributing heat to the coil.

That is, my HP puts out MORE BTUs at 45°F when its raining than when its sunny. Bc when its raining, the outdoor coil is at 45°F (wet-bulb), whereas when its sunny, it is probably more like 38-40°F (dry-bulb-5-7°F). I can tell by measuring the temp of the air coming out of the registers.

Thank you for this explanation on wet and dry bulb. That was something I was surely not clear on!

 

[Potluck_Crew]

So you can see that the TC shows heat produced so at 45 dedgres wet bulb temp outside you and get 22.2 k btus (at 70 degrees inside temp) consuming 1.6 kw. At 5 degrees wet bulb you get half of that 10.3 k btus using 0.87 kw. I’m not sure why they use wet bulb outside.

With out any frost comment I assume is meaning no ice on the outside coil causing the unit to defrost.

And you said you have 5 of those 1.5 ton units? Even at at 15 degrees you have over 60,000 btus of heating capacity. And could consume 6kw. Now they all might not runn at the same time or at full output.


Here is a similar chart for my unit. Outdoor temps on the left column indoor return temp is along the top.

View attachment 291397

So, I thoroughly enjoyed working the math and formulas(Retired Middle school Math Teacher) .

I learned about COP, Coefficient of Performance and used the formula and steps I found on this website: https://www.pickhvac.com/faq/heat-pump-cop/

Here is a chart of our particular system. In the spec sheets, it does list a COP of 4.11

I know this is a very simple interpretation of the system.

 

[Brian26]

The choice of wet-bulb outside is bc of condensation/frosting. Under dry conditions, the outdoor coil runs a few degrees cooler than the outdoor air (dry-bulb) temp. If its humid outside, such that condensation forms, the outdoor coil runs warmer, at the wet-bulb temp, rather than the dry-bulb temp - Delta T. With the heat of condensation contributing heat to the coil.

That is, my HP puts out MORE BTUs at 45°F when its raining than when its sunny. Bc when its raining, the outdoor coil is at 45°F (wet-bulb), whereas when its sunny, it is probably more like 38-40°F (dry-bulb-5-7°F). I can tell by measuring the temp of the air coming out of the registers.

Yeah. There is a noticeable difference in heat output with high wet bulb temps. I'm on the shoreline that has constant high outdoor wet bulb temps. Right now its in the upper 40's with 100% humidity and I just turned on one of my splits and its incredible how much heat it putting out at its minimum capacity using only 200 watts. I often see my outdoor condenser coil with a steady stream of water from the basepan. Its incredible how much that huge outdoor coil can sweat in high wet bulbs.

 

[Potluck_Crew]

We need some creative minds. New owners of old home since July. We have Solar System that generates between 350 to 600 per month. We are on net metering through National Grid.

Our electrical/heating profile
Solar Panels Size: 5.04 kWdc, Monitoring Site: https://www.solrenview.com/SolrenView/mainFr.php?siteId=522
5 mini splits 15 years old
Appliances are mostly 10 years or older, so not as efficient.
Heat: Harman Accentra insert from 2008-we've tested it for electrical draw-pretty much as expected.
Oil Burner that runs both radiation steam heat and radiant heat. Both on programmable thermostats.

Sounds totally awesome right??
Things were moving along great in July, Aug, Sept, Oct .Total KWh usage of 10 to 50 per month(with the Net Metering). This translated to monthly bills of under $25.

Then in Nov/Dec...everything changed and it was huge. Our bill for Nov (which didn't arrive until Dec 20) showed 930 Kwh usage(Net). Then the next bill arrived with a 1500 Kwh(Net) usage.

We IMMEDIATELY shut down the mini splits, which we were already using sparingly, relying mostly on Pellet stove and some oil based heat.

Fast forward till late January, next bill showed 1000 Kwh usage.

We asked National Grid to come investigate if the net meter was working correctly. No finding.View attachment 291153

We had a virtual Home Energy assessment with Mass Saves. Main finding was need for more insulation, which would not have increased the electrical usage except in oil burner and pellet stove use.

We purchased a Kill A Watt measuring device to test pellet stove as use was added in Nov.

The pellet stove may account for some KWh increase but not the huge one. Averaging a draw of between 120watts (lower settings) and 180watts (full power). We thought perhaps the igniter was stuck on, but not the case!

I report the Solar Generation each month to Mass CEC, so I know it is producing.


Where do we go from here? Any ideas on things we should check?


View attachment 291154

We have electrician coming tomorrow(2/8) to install the Emporia Vue to our main panel. Hubby could do it, but we also have a few other electrical jobs to be done. Looking forward to unravelling our puzzle.

 

[Potluck_Crew]

Getting closer to the answer. Installed a Emporia Vue2 on the main electrical panel, and the electricians are coming back to install a 2nd one on the sub panel that holds HWH, Mini Splits. We have been trying to chase down the various circuits on the main panel. They had changes over the last few years apparently and are not labeled correctly. More sleuthing! We do see that our Fridge is not very efficient by today's standards....This snapshot is just of the last hour's electrical use on the main panel(Warm day, not calling for boiler, no laundry going right now....)

 

[Potluck_Crew]

We think we have the answer...finally. One of our 3 split system outside units is malfunctioning.
We finally had the 2nd vue energy monitor installed on the 2nd circuit panel.

Measuring the two units, both with the inside units OFF, one used .03 Kw in an hour, the malfunctioning one, .5Kw in the hour. So we will get a tech over to take a look. Both of these outside units are raised off the ground and have good circulation.

In regards to the heatpump hot water heater, only 2 days in with the energy monitor. We set it a month ago on HEATPUMP only. In two days of monitoring it used average of 3kWh a day. (both weekend days with lots of activity!)

I am so appreciative of all the help this forum has given. I have found a new thing to study in my retirement...energy use!

 

[Brian26]

We think we have the answer...finally. One of our 3 split system outside units is malfunctioning.
We finally had the 2nd vue energy monitor installed on the 2nd circuit panel.

Measuring the two units, both with the inside units OFF, one used .03 Kw in an hour, the malfunctioning one, .5Kw in the hour. So we will get a tech over to take a look. Both of these outside units are raised off the ground and have good circulation.

In regards to the heatpump hot water heater, only 2 days in with the energy monitor. We set it a month ago on HEATPUMP only. In two days of monitoring it used average of 3kWh a day. (both weekend days with lots of activity!)

I am so appreciative of all the help this forum has given. I have found a new thing to study in my retirement...energy use!

Thats probably normal for the mini splits to draw some power when they are off. The compressors have an electric heat wrap to keep them warm. When its cold liquid refrigerant will settle in the compressor and can damage it if it tries to run when its cold.. I have the Emporia vue as well and you can actually see the heater come on.

 

[Potluck_Crew]

Thats probably normal for the mini splits to draw some power when they are off. The compressors have an electric heat wrap to keep them warm. When its cold liquid refrigerant will settle in the compressor and can damage it if it tries to run when its cold.. I have the Emporia vue as well and you can actually see the heater come on.

I can see it is normal for the cycling on/off and defrost cycle. But the one we feel is malfunctioning used about 15x the electrical draw in the same time frame. Love the Vue, wish I would started months ago with it. Would have saved us some buck with our 27 cents per kwh!

 

[semipro]

I have found a new thing to study in my retirement...energy use!

Have you started looking at parasitic draws elsewhere yet, for fun you know?
Certain devices found in entertainment centers are particular culprits (e.g satellite and cable boxes).
I ended up putting our entertainment center on a smart receptacle to address these losses.

 

[Potluck_Crew]

Have you started looking at parasitic draws elsewhere yet, for fun you know?
Certain devices found in entertainment centers are particular culprits (e.g satellite and cable boxes).
I ended up putting our entertainment center on a smart receptacle to address these losses.

Yes, likely, now that we found the big draw! In one month our usage went up 300%! This vue energy monitor is amazing! We have on order a new fridge. Current one works, but is about 20 years old and not very efficient. Dining room outlets reflect pellet stove draw.

 

[fire_man]

Oh, the joys of heating a house through the New England winter!

Your electric usage does seem high for non-electric resistance heat.

Not a great referene for comparison... but in our 2500 sqft, poorly insulated house which is also in MA, we used 800 kWh in December. That was with 1 mini split running, a bunch of christmas lights, electric stove baking, 2 wood stoves, gas hot water. An average month for us is closer to 500-600 kWh. We don't have solar.

I believe that with a bit of patience and deductive reasoning you will find the culprit, and I would bet it's a resistive heating element somewhere.

Here is another reference for comparision:

We have a similar setup (2300 sq ft house, not great insulation) in the same climate. Two woodstoves, Oil fired hot water heater, Large Fridge (25 years old) , Basement Freezer, Electric Dryer, Electric range . My usage was 423 KWH Dec 15-Jan 15 which included christmas lights compared to your 800 KWH . Eyeballing my chart it looks like my monthly average is around 500 kWH. No Solar. My usage does seem kind of low especially considering I have such an old Fridge and a separate Freezer.

I'm guessing you are not using the 2 Woodstoves as much as me and your Minisplit made up most of the 377 KWH difference in December. My Summer spike is due to a dehumidifier and AC.

 

[Potluck_Crew]

Here is another reference for comparision:

We have a similar setup (2300 sq ft house, not great insulation) in the same climate. Two woodstoves, Oil fired hot water heater, Large Fridge (25 years old) , Basement Freezer, Electric Dryer, Electric range . My usage was 423 KWH Dec 15-Jan 15 compared to your 800 KWH . Eyeballing my chart it looks like my monthly average is around 500 kWH. No Solar.

I'm guessing you are not using the 2 Woodstoves as much as me and your Minisplit made up most of the 377 KWH difference in December. My Summer spike is due to a dehumidifier and AC.

View attachment 293581

Yes, the

Here is another reference for comparision:

We have a similar setup (2300 sq ft house, not great insulation) in the same climate. Two woodstoves, Oil fired hot water heater, Large Fridge (25 years old) , Basement Freezer, Electric Dryer, Electric range . My usage was 423 KWH Dec 15-Jan 15 compared to your 800 KWH . Eyeballing my chart it looks like my monthly average is around 500 kWH. No Solar. My usage does seem kind of low especially considering I have such an old Fridge and a separate Freezer.

I'm guessing you are not using the 2 Woodstoves as much as me and your Minisplit made up most of the 377 KWH difference in December. My Summer spike is due to a dehumidifier and AC.

View attachment 293581

Yes, we only have one pellet stove. It is undersized for whole house heating so when it is cold, it runs full force.(about .25kw per hour) That eats up some electric. I do appreciate the comparison. We have a basement freezer we have not plugged in yet. Trying to see if we can get by without it.

Having tech come look at one mini split which we believe is malfunctioning after putting an energy monitor on everything. It used 15x the energy as another split outside unit, same timeframe, temp and demand.

Other electrical savings steps we are/have taken: new pellet stove on order-sized for whole house heat. New fridge(energy star rated) on order that will hopefully cut that usage in half. We set the water heater on heat pump only and that is helping!

Finally getting some answers!

Thanks

 

[fire_man]

Yes, likely, now that we found the big draw! In one month our usage went up 300%! This vue energy monitor is amazing! We have on order a new fridge. Current one works, but is about 20 years old and not very efficient. Dining room outlets reflect pellet stove draw.

View attachment 293548 View attachment 293549

Would you mind sharing the cost for the Vue monitor including the cost to install in both panels ?
Had you researched other monitors as well? I really like the level of detail you get and the friendly easy to understand display.

 

[Potluck_Crew]

Would you mind sharing the cost for the Vue monitor including the cost to install in both panels ?
Had you researched other monitors as well? I really like the level of detail you get and the friendly easy to understand display.

I had not done much research on other monitors, but saw on this Forum the type of details that were available and that Vue was now a 2nd generation product. I went for it. The cost from Amazon..
Full "kit" monitor, and 16 circuit monitors was $150. A smaller kit with monitor and 8 circuit monitors was $110.
I bought full kit first, had installed. Then purchased smaller kit and it was installed later.
You do have to have a 2.4 GHz wifi available. (We had to add a wifi range extender in the basement.)

The first kit, with 16 monitors went into a jammed packed panel. It took 2 man hours of electricians doing it. The 2nd kit with the 8 monitors, I haven't gotten the bill for yet, but I think it was only 1 man hour. Our rates here in central MA are $85 per man hour. So all in all, my total cost for installation are likely about $270.

Depending on your basic electrical comfort level, you might be able to put in yourself. My husband preferred that the electricians do the work. There are some youtube videos that you can watch about the basic monitor and also installs. So all in, I have over $500 in the system. for 2 Circuit panels. But the savings will surely pay for itself. We went from a $20 electric bill to a $270 in one month.

For a 240 amp breaker, once you verify that both circuits are fairly equal, you can move one of the monitors to another breaker, and set a multiplier of 2. In my images in previous post, I have the boiler, water heater and dryer set up that way. It makes your 16 sensors go farther. I am totally comfortable in moving the sensors around to different circuits.

Here is the link to Amazon and the product: Amazon product ASIN B08CJGPHL9

 

[fire_man]

I had not done much research on other monitors, but saw on this Forum the type of details that were available and that Vue was now a 2nd generation product. I went for it. The cost from Amazon..
Full "kit" monitor, and 16 circuit monitors was $150. A smaller kit with monitor and 8 circuit monitors was $110.
I bought full kit first, had installed. Then purchased smaller kit and it was installed later.
You do have to have a 2.4 GHz wifi available. (We had to add a wifi range extender in the basement.)

The first kit, with 16 monitors went into a jammed packed panel. It took 2 man hours of electricians doing it. The 2nd kit with the 8 monitors, I haven't gotten the bill for yet, but I think it was only 1 man hour. Our rates here in central MA are $85 per man hour. So all in all, my total cost for installation are likely about $270.

Depending on your basic electrical comfort level, you might be able to put in yourself. My husband preferred that the electricians do the work. There are some youtube videos that you can watch about the basic monitor and also installs. So all in, I have over $500 in the system. for 2 Circuit panels. But the savings will surely pay for itself. We went from a $20 electric bill to a $270 in one month.

For a 240 amp breaker, once you verify that both circuits are fairly equal, you can move one of the monitors to another breaker, and set a multiplier of 2. In my images in previous post, I have the boiler, water heater and dryer set up that way. It makes your 16 sensors go farther. I am totally comfortable in moving the sensors around to different circuits.

Here is the link to Amazon and the product: Amazon product ASIN B08CJGPHL9

Thanks for the great details. I can imagine if the panel was already jam packed it might be tricky to install. I can see how especially in your case it would pay for itself quickly due to a defective appliance. I like that the sensors are magnetically coupled so no need to break any connections.​

On a similar subject, I have heard horror stories about people with outrageous water bills due to one leaky toilet.