Fridge power consumption

Daox · 09-23-10, 08:28 AM

I just stuck a kill a watt on my fridge for the first time. I was quite disappointed to see it using 10W+ constantly. I know it has a few fans in it that are on almost all of the time. Anyway, I checked it this morning and the power usage was up to .81kWh after 11.5 hrs. So, I can be pretty sure its using around 1.65 kWh per day. This seems a bit high, especially for a newer fridge (its only 2 years old). Does anyone else have power consumption numbers on their fridge?

RobertSmalls · 09-23-10, 10:06 AM

My fridge's consumption varies a fair amount from day to day, so the calendar on the fridge doubles as a notepad, full of KaW readings and times of day. It's about 1KWh/d in the summer, and I'd guess it's around 0.8KWh/d now.

That's an awful lot of power, but it turns out, it's fairly low among fridges. It doesn't say Energy Star anywhere on it, but it's probably thrifty enough to qualify.

Piwoslaw · 09-23-10, 03:50 PM

Mine uses 0.7kWh/day. read more here and here.

Daox · 09-23-10, 04:39 PM

I've even reduced my temperatures to 40F for the fridge and 5F for the freezer. I don't think there is much left to do besides adding insulation, and the wife won't like that one too much unless I can make it look nice and pretty. I did pull it a bit farther away from the wall when I put the kill a watt on it too, it was very close and it was pretty warm back there.

I'll try cleaning the coils.

NiHaoMike · 09-23-10, 09:49 PM

Chest fridge

Daox · 09-24-10, 06:34 AM

I'm aware of that, we had or own thread here and blog about it. I don't have room to do that unfortunately.

After 24 hrs the consumption was almost exactly 1.5 kWh.

RobertSmalls · 09-24-10, 07:37 AM

Quote:

Originally Posted by NiHaoMike

Chest fridge

It's not as impressive as it looks, unless you have the refrigeration requirements of a vegan. When you consider that his fridge is set very high, his ambient was fairly cool, and I'd need a second unit for the freezer, if I were to emulate that setup, I'd use 0.6KWh/day. Piwoslaw's fridge is almost there, and I'm hoping to get close with the vinyl shower curtain I installed in the fridge, plus some insulation that I'd like to add.

NeilBlanchard · 09-25-10, 07:06 PM

How big are your fridges? Our 27 cu ft (20 fridge 7 top freezer, for a family of four) is 18 years old and uses 1.6kWh/day. It may need to be replaced soon...

kd8cgo · 09-25-10, 07:07 PM

I just did a chest fridge setup to replace an old 14cuft Crosley we had that would suck up 1.6Kwh on a good (cool) day. I have to say energy use is good, but not great so far. I didn't buy Energy Star rated freezers as they were not available locally in the sizes I wanted, so the results could be better, but here's what I've noticed so far.

I bought a 5cuft for a freezer and a 7cuft for the refrigerator, both the GE models available from Home Depot. I used a Ranco ETC-111000 control for the fridge. This setup uses from .8Kwh to .9Kwh per day, depending on average indoor temperatures which has been between 71 and 82F since I started using these freezers. The freezer must be turned all the way down to try to achieve the 5F residential setting that I am looking for, and it seems to have a fairly large dead band at this setting, probably because it is adjusted to the lowest extent of the range in one direction. Fridge is set at 40F.

The hot coils are on all 4 sides of the exterior of these units, so additional insulation is not practical unless you just want to do the bottom and top. The wife likes them so far, which was one of my biggest worries, but it is actually easier to see and reach the food you use most often, without the "sideways fridge lean and look" commonly associated with top freezer designs. In hindsight, I could have waited and ordered a smaller ~3cuft freezer for our needs, the fridge size on the other hand is just about right though.

The Ranco unit is nice in that both heat or cool can be selected, and temperature set point and dead band are adjustable in 1F increments. The Ranco unit is not ideal however - it uses 2W at all times and contributes to 5-6% of the total daily Kwh load, I will probably work up my own temperature controls for fridge and freezer both to gain some additional savings and control.

If you are going to do a chest fridge, don't get too hyped up about super energy savings unless you don't need the freezer component like in those articles you've all read. I've not measured the units separately yet to see how much each unit is contributing to the energy cost, but that's on the to-do list.

NiHaoMike · 09-25-10, 11:19 PM

Has anyone tried replacing the capillary tube with a TXV? Or maybe even replace the compressor with an inverter drive type, add some more condenser area, and (for the freezer) use a low boiling point refrigerant like R-410a.

I suppose it could be possible to start with a very well insulated cooler, add even more insulation to it, and divide it up into two parts. The evaporator will only directly cool the freezer part, while a small 12V fan is electronically controlled to circulate cold air into the refrigerator part.

09-23-10, 08:28 AM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Fridge power consumption I just stuck a kill a watt on my fridge for the first time. I was quite disappointed to see it using 10W+ constantly. I know it has a few fans in it that are on almost all of the time. Anyway, I checked it this morning and the power usage was up to .81kWh after 11.5 hrs. So, I can be pretty sure its using around 1.65 kWh per day. This seems a bit high, especially for a newer fridge (its only 2 years old). Does anyone else have power consumption numbers on their fridge? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-23-10, 04:39 PM	#4
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I've even reduced my temperatures to 40F for the fridge and 5F for the freezer. I don't think there is much left to do besides adding insulation, and the wife won't like that one too much unless I can make it look nice and pretty. I did pull it a bit farther away from the wall when I put the kill a watt on it too, it was very close and it was pretty warm back there. I'll try cleaning the coils. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-23-10, 09:49 PM	#5
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Chest fridge __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

09-24-10, 06:34 AM	#6
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I'm aware of that, we had or own thread here and blog about it. I don't have room to do that unfortunately. After 24 hrs the consumption was almost exactly 1.5 kWh. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 09-24-10 at 07:45 AM..

09-25-10, 11:19 PM	#10
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Has anyone tried replacing the capillary tube with a TXV? Or maybe even replace the compressor with an inverter drive type, add some more condenser area, and (for the freezer) use a low boiling point refrigerant like R-410a. I suppose it could be possible to start with a very well insulated cooler, add even more insulation to it, and divide it up into two parts. The evaporator will only directly cool the freezer part, while a small 12V fan is electronically controlled to circulate cold air into the refrigerator part. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

09-23-10, 10:06 AM	#2
RobertSmalls Journeyman EcoRenovator Join Date: May 2009 Location: Buffalo, NY Posts: 344 Thanks: 3 Thanked 17 Times in 15 Posts	My fridge's consumption varies a fair amount from day to day, so the calendar on the fridge doubles as a notepad, full of KaW readings and times of day. It's about 1KWh/d in the summer, and I'd guess it's around 0.8KWh/d now. That's an awful lot of power, but it turns out, it's fairly low among fridges. It doesn't say Energy Star anywhere on it, but it's probably thrifty enough to qualify.

09-23-10, 03:50 PM	#3
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Mine uses 0.7kWh/day. read more here and here.

09-25-10, 07:06 PM	#8
NeilBlanchard Journeyman EcoRenovator Join Date: Dec 2009 Location: Maynard, MA Eaarth Posts: 383 Thanks: 78 Thanked 39 Times in 32 Posts	How big are your fridges? Our 27 cu ft (20 fridge 7 top freezer, for a family of four) is 18 years old and uses 1.6kWh/day. It may need to be replaced soon...

09-25-10, 07:07 PM	#9
kd8cgo Lurking Renovator Join Date: Sep 2010 Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	I just did a chest fridge setup to replace an old 14cuft Crosley we had that would suck up 1.6Kwh on a good (cool) day. I have to say energy use is good, but not great so far. I didn't buy Energy Star rated freezers as they were not available locally in the sizes I wanted, so the results could be better, but here's what I've noticed so far. I bought a 5cuft for a freezer and a 7cuft for the refrigerator, both the GE models available from Home Depot. I used a Ranco ETC-111000 control for the fridge. This setup uses from .8Kwh to .9Kwh per day, depending on average indoor temperatures which has been between 71 and 82F since I started using these freezers. The freezer must be turned all the way down to try to achieve the 5F residential setting that I am looking for, and it seems to have a fairly large dead band at this setting, probably because it is adjusted to the lowest extent of the range in one direction. Fridge is set at 40F. The hot coils are on all 4 sides of the exterior of these units, so additional insulation is not practical unless you just want to do the bottom and top. The wife likes them so far, which was one of my biggest worries, but it is actually easier to see and reach the food you use most often, without the "sideways fridge lean and look" commonly associated with top freezer designs. In hindsight, I could have waited and ordered a smaller ~3cuft freezer for our needs, the fridge size on the other hand is just about right though. The Ranco unit is nice in that both heat or cool can be selected, and temperature set point and dead band are adjustable in 1F increments. The Ranco unit is not ideal however - it uses 2W at all times and contributes to 5-6% of the total daily Kwh load, I will probably work up my own temperature controls for fridge and freezer both to gain some additional savings and control. If you are going to do a chest fridge, don't get too hyped up about super energy savings unless you don't need the freezer component like in those articles you've all read. I've not measured the units separately yet to see how much each unit is contributing to the energy cost, but that's on the to-do list.