[DebF_EONNext]

I am really enjoying reading this thread @wizzo227 this is a great experiment and it's really interesting reading the results. I myself use an airfryer, although I haven't tracked the kWh it cooks the food in much less time than my LPG oven so by default I would imagine it uses much less energy too, also saves some pennies which is always a bonus!

[Mailman]

If I can just add that with the IHD I have has a useful metric that I can pull up which is 'Usage Now' so it will display the actual watts being used. A smart man's energy monitor if you like. 😉

[retrotecchie]

@Mailman

Ah, but that will only give 'Usage Now' for the entire house...not an individual appliance.

Unless of course you disconnect any intermittent loads and then calculate ΔP from the difference between two readings...

[wizzo227]

@DebF_EONNext
Thanks for encouragement. Any chance of a recipe suggestion for the air fryer and power used? They advertise on energy-saving, so like-for-like comparison with reheat bolognese on an electric hot plate cooked stacked could be useful, because that could discover the exaggeraticity number describing the truthfulness of air fryer advertisers. Anything which you are eating anyway, and preference for one which plays to the strengths of your air fryer, and I'd try to work out how I'd cook the same quantity of the same food here. Please also say something about quantity. For example my standard size for a plate of spagetti bolognese makes 500g finished cooked food, and I count that as one full sized hot meal.

Do you know the "calorific" constant of what goes into your LPG burner and is the quantity metered? I'd expect a blend with more propane to slightly increase from 39.2 MJ/(m^3) at 15C 1.0bar, which is for methane from my gas bill and which works out at 11.13 kWh/(m^3).

[Mailman]

Originally Posted by retrotecchie

@Mailman

Ah, but that will only give 'Usage Now' for the entire house...not an individual appliance.

Unless of course you disconnect any intermittent loads and then calculate ΔP from the difference between two readings...

Sort of.

Whenever I've checked the draw of a single appliance I'll see what the usage now reading is. If baseline draw is steady, connect up the appliance and yes calculate ΔP from the difference between two readings.

I agree that it is no going to be accurate as a dedicated plug for power consumed between 2 time periods but I find it useful to see stuff like, the difference in draw between FF compressor on/off , the difference in power consumed when CH pump on/off, the extra draw when the heat pump tumble dryer is being used and so on. I can get a ball park figure for the total usage if say I run the dryer for 30 mins. Obviously not so good for something that is on for a very short time like a kettle although easy enough if you look at the difference in the kWh consumed so far today metric on the IHD.😁

[wizzo227]

Test Case 01-Mar-23 Two Slices of Cheese On Toast,
cooked in the smallest type of Belaco Mini Oven
used 0.196 kWh

Identical food to 23rd Feb, even going back to the same shop for the same plain white bread. This time I weighed everything.
170 grams = two slices of generously cheesy toast with a spoonful of tomato-based 'red pesto'
So a snack; about 1/3 of the bolognese test meal. By comparison to using the main oven, the mini-oven used less than 1/4 as much electricity.

Carbon emissions improved more than that because 'some' of the electricity used was from local solar. The mini oven, advertised as "650 Watts" was using 725 Watts, possibly due to the mains here being a little over 242 Volts rms, and not the European 220 Volts which some appliances get tested with.

I'm not going to tell anyone to throw away their full sized oven, because this mini oven is the right size only for a hot snack for one person. For example half a ten-inch pizza is 200 grams, and that really fills up the mini oven compartment. Where it excels, is in being the 'right' size for a snack and being inside rooftop solar generation surplus more often than a full sized oven.

https://belaco.co.uk/product/belaco-...ble-oven-650w/
Comparing to the manufacturers' claim, it is Not capable of 250C. The dial goes up to "230" and it cooks soggy pizza rather like my proper oven would at 170C. It was slower than the normal oven/grill doing todays' cheese on toast, and never did pre-dry the tomato layer as would the proper grill. It is Not powerful and further limited by its maldesigned cost-reduction thermostat. To prevent people like me from unscrewing the case and bypassing their defective thermostat, the manufacturer riveted the case on instead. Next time I'll use it for something which plays to its strengths, which is to bake a two-egg Victoria sponge cake in an 8" x 4" baking tin at minimum kWh.

If you are a penny-pinching office manager and you really hate and need to demean your workforce, buy one of these for the office common room and command the minions to form an orderly queue at lunchtime.

[DebF_EONNext]

How is the experiment going @wizzo227?

I don't know the actual kWh used as I have nothing to measure. I do have my IHD however I have this hidden away (I was becoming obsessive!) I don't know if you're able to work anything out with the following info?

Example: Mini Roast Potatoes

750g baby potatoes 🥔, washed, coated in garlic butter and rosemary and seasoned. Placed in the airfryer whole & raw at 200c for 22m.

Airfryer: 2400 watts / No preheat required. (this is dual drawer so I am unsure if this changes anything if only using 1 drawer)

V.S

750g baby potatoes 🥔, washed, coated in garlic butter and rosemary and seasoned. Placed in the LPG oven whole & raw at gas mark 6 for 47m

LPG oven: We use Butane but I have no idea how much is used each time, according to supplier we get 35h per cylinder however this usually lasts us 6 months 🤷‍♀️ I have to add that using the cooker the oven also needs to preheat for 15m too to get to temperature.

Airfryer: Total time 22m
LPG Cooker: Total time 1hr 2m

Take from this what you wish...I don't know how useful it will be but hey-ho I tried 😂

[retrotecchie]

@DebF_EONNext

If it's the red/orange Calor bottles, it'll be propane. Butane in your blue bottles (patio gas or Camping Gaz) doesn't like low temperature environments, so isn't so good in winter for cooking or heating. The different gasses regulate at different pressures too and need completely different burner profiles and air/fuel ratios.

Mind you, even propane regulators freeze up in really cold weather. If I needed the gas hob in minus outdoor temperatures, I used to have to pour a jug of warm water over the regulator until you heard the springs ping.

[DebF_EONNext]

@retrotecchie it's defo butane we use as it's the only bottle that fits the regulator ( it's 20mm, it's an old odd size that doesn't fit Calor and is in the process of being discontinued which is great news 🤦‍♀️) , we have a purpose built safety fire cabinet thing to house the canister indoors so it has to be butane to meet safety regs apparently, so it means we don't usually have to worry about the regulator freezing generally, but yes you are correct it's usually used for patio heating 😊

[retrotecchie]

@DebF_EONNext

Ok, definitely sounds like butane then. If indoors, that gets round the freezing problem. 👍