Slow cooker v oven - energy consumption

[Harry Bloomfield]

On the news this morning, an item about the energy saving advantages of slow cookers, versus an oven. I've heard it said before, but I am really not convinced there is that much advantage, especially when comparing cost of an electric slow cooker, versus a gas oven.

Yes, I do have a couple of slow cookers, which I tend to only use for food best cooked low and slow. My two (without investigating), seem to use a fixed wattage settings, rather than thermostatically controlled for temperature. Consumption seems to be around 100w, so 6 hours = 0.6Kwh in total. I wonder what a typical oven might use, cooking a similar meal?

 

[motorbiking]

900w for 45 mins? The issue with the oven is you are heating a larger area. An Air fryer is basically just a small fan oven.

An air fryer would cook pie and chips for example in around 2/3rds the time of an oven, for about the same power.

 

[Harry Bloomfield]

An air fryer would cook pie and chips for example in around 2/3rds the time of an oven, for about the same power.

I bought a cheap air fryer, but was rather disappointed that it cooked only the items at the top, so needed lots of attention to shaking up the contents and the 'none stick' basket was impossible to get clean after use. I tend not to use it much now, or add a cooking foil, in the bottom.

 

[martygturner]

900w for 45 mins? The issue with the oven is you are heating a larger area. An Air fryer is basically just a small fan oven.

An air fryer would cook pie and chips for example in around 2/3rds the time of an oven, for about the same power.

Well the average uk single electric fan oven at 180c/200c uses between 0.71kwh and 0.91kwh

eg https://ao.com/product/bi64211pb-hisense-electric-single-oven-black-93370-45.aspx

A dual basket air fryer typical uses 2kwh on max +200c as does a single and 1.7kwh on low @180c

https://ao.com/product/hd928091-philips-essential-xl-connected-fryer-black-94452-97.aspx

A slow cooker on low is at around 0.075wh and on high 0.1kwh. But is only any good with wet foods.

So really the argument is how long do you need to cook the food you want.

eg. a family of four Chicken and chips :

Air Fryer. - it takes just as long to cook a chicken at 180c as an oven, there is no magic the chicken is still being cooked at 180c, so it takes 40 mins for a small one and then 20 mins for some chips @ 200c . average time 1 hour for the meal. so 1.8kw in total. (40mins at 1.7kw @ 20mins and 2.0kw)

Oven - again the chicken will take 1 hour mins @180 and the chips 35 mins - but you can cook both together so its 1 hour. Oven to temp is 10 minutes so all in all 1 hour 10 minutes....oven therefore uses 1.038kw

Air fryers were not sold as being energy efficient they were sold as being healthy...then all of a sudden.......

Unless you are cooking small batches of food that has a short cooking time why bother , if you want less fat in your diet then bring it on.

The average time for a stew in a slow cooker is 8 hours on low so 0.75wh x 8 hours is 0.6kwh used.

 

[crystal ball]

Sliced Bread - Air Fryers - BBC Sounds

Air fryers - can they save you money?

www.bbc.co.uk

 

[Harry Bloomfield]

A slow cooker on low is at around 0.075wh and on high 0.1kwh. But is only any good with wet foods.

That is what I always understood, but I saw one being used for dry food recently, so had in mind to try it with dry. I have yet to get around to that.

 

[Mr Chibs]

A dual basket air fryer typical uses 2kwh on max +200c as does a single and 1.7kwh on low @180c

https://ao.com/product/hd928091-philips-essential-xl-connected-fryer-black-94452-97.aspx


Air Fryer. - it takes just as long to cook a chicken at 180c as an oven, there is no magic the chicken is still being cooked at 180c, so it takes 40 mins for a small one and then 20 mins for some chips @ 200c . average time 1 hour for the meal. so 1.8kw in total. (40mins at 1.7kw @ 20mins and 2.0kw)

Oven - again the chicken will take 1 hour mins @180 and the chips 35 mins - but you can cook both together so its 1 hour. Oven to temp is 10 minutes so all in all 1 hour 10 minutes....oven therefore uses 1.038kw

Air fryers were not sold as being energy efficient they were sold as being healthy...then all of a sudden.......

Just curious about this... if the air fryer is a small fan oven, why does the energy usage you've quoted assume that it is using full energy consumption for the whole cooking time?

Conventional ovens don't go full pelt for the whole time, so wouldn't the air fryer do the same?

 

[martygturner]

Just curious about this... if the air fryer is a small fan oven, why does the energy usage you've quoted assume that it is using full energy consumption for the whole cooking time?

Conventional ovens don't go full pelt for the whole time, so wouldn't the air fryer do the same?

Errr what - they both measured by their stated energy consumption per hour...

Take a standard a+ rated fan oven with a 3kw heater, - that will run full tilt for say 10 minutes to get the oven up to 180c - so its used 500w but then as its at temp it cycles down off and on for the next 50 minutes using a further 500w , its energy usage per hour is 1 kw or 1 kwh

An airfryer might use a 2kw heater and need to be heating for 30 minutes in a hour to keep to 180c...result its usage per hour is 1 kw or 1 kwh.

Energy consumption is measured by the total work done to achieve a task ie it takes 1 calorie of energy to heat 1ml of water by 1 degree c. its not a measure of how that energy is applied.

By the way the most energy efficient is a microwave as it only heats food not space.

 

[Notch7]

an electric uses around 1kw per hour from what I’ve found online…it’s rather hard to be accurate as it all depends on amount of heat being absorbed by the food and the rate of heat loss

recipes which are just heating through like say baked potatoes can be put in when oven switched on, then turn oven off 10 mins before taking out.

 

[big-all]

what i used to do was cook on a lower setting and cover with a doubled up thick bathroom towel
of course never do it near a naked flame or leave unattended until you have done it several times
dont fill to the top as the towel can soak up anything that bubbles past the lid into the rim

 

[Dork Lard]

I bought one of these : https://ninjakitchen.co.uk/product/...ith-smart-cook-system-7-5l-ol750uk-zidOL750UK

Then bought one of these : https://www.tapo.com/uk/product/smart-plug/tapo-p110/

The first time I slow cooked beef at 60deg C for 6hrs . . . . The taste of that beef was worth every penny.