Energy usage

[Harry Bloomfield]

that might be the theory, ours was under the window, with the curtains closed the warmest prt of the room was behind the curtains next to the cold glass where heating loss is greatest.

I moved them to another part of the room and it made a notable improvement to how the room felt, certainly made the room warmer.

We used to have floor to ceiling thermal curtains in the bay, with the radiator behind the curtain - pre-DG. I changed that to shorter curtains, inside the window recess, which made a big difference to warmth. Post DG, I've found curtains unnecessary, I just have decorative curtains up which are never drawn and vertical blinds, for those days when the sun stream in through the bay. I am not over-looked, so no need for privacy curtains.

 

[winston1]

I'm sure an individual with your wherewithal could put a CT clamp on the relevant circuit?! Quite a few Raspberry Pi projects around the web will do multiple simultaneous clamps..

CT clamps measure current not power. Useless for any load with a less than unity power factor.

 

[Harry Bloomfield]

There chimes the forum pendant again.

 

[winston1]

There chimes the forum pendant again.

If you don't understand the basics don't insult those that do.

 

[Harry Bloomfield]

It's about what is important and relevant to the original question the OP posted. Limiting the complexity to the matter which was being discussed. The more technical amongst us are well aware that a measure of current is not the same as power, but for the purposes of the discussion it is near enough.

A rough measurement of current is all that is needed to satisfy the needs of the OP. Why constantly interrupt discussion with your unnecessary pedantry? Rather than demonstrating how clever you are, you are demonstrating quite the opposite, as well as being insulting with your mention of 'not understanding the basics'. Keep in mind - That there are many taking part in this thread, much brighter, much cleverer, and far better qualified than you - the thing is, they are bright enough to bite their lip and control their inclination towards being pedantry.

In other words - Do yourself a big favour, and take a day off.

 

[winston1]

It's about what is important and relevant to the original question the OP posted. Limiting the complexity to the matter which was being discussed. The more technical amongst us are well aware that a measure of current is not the same as power, but for the purposes of the discussion it is near enough.

No it isn't. A washing machine, fridge, in fact anything with a motor will show a inflated reading.

A rough measurement of current is all that is needed to satisfy the needs of the OP.

Only because he may not know the error.

Keep in mind - That there are many taking part in this thread, much brighter, much cleverer, and far better qualified than you -

Maybe. I'm AMIEE. Interested to know about the many.

 

[DetlefSchmitz]

There chimes the forum pendant again.

Surely a pendant is something that needs hanging?

 

[Harry Bloomfield]

Only because he may not know the error.

Does he really need to know the error - answer is no.

 

[Harry Bloomfield]

Surely a pendant is something that needs hanging?

Quite

 

[jacko555]

And ideally 240v run through it

 

[ericmark]

CT clamps measure current not power.

Don't need to know current for the oven, what is needed is time, I can look in the over manual to get power used by rear, side, and top elements, the fan is not enough to worry about, but I need to measure the time each element is used for, and without a cooker sized energy meter which would need hard wiring in, can't really measure the time, well I suppose could rig some thing up to record how long the red lamp is on for with oven, but the times are far too short to measure with the hob, and your comment about power factor is likely valid for the induction hob.

Because the air being cooled by the window convects down, and the air being warmed by the rad convects up, the two meet at around windowsill area and mix, funnelling out into the room.

I have two diagrams not sure I agree with either, since my house living room two radiators at 90° to each other, but the comment pre-double glazing is valid, as I remember my first house, gas hot air central heating, warmed the house fast, but also cost a lot, because the fan moved the air around so no cold or hot spots, but noted first with mothers house, within her living room recorded in winter at same point of time 16°C and 24°C in her case it was down to bay windows catching the sun, but today in my living room 2 x TRV heads and a baby alarm all showing in my bedroom the living room temperature, 17°C, 18°C and 16°C some days there is more of a difference within the same room. All recorded low down, and this is a problem as the body hight temperature is much higher, my hall is often showing even more now showing at TRV 16°C and at Nest Gen 3 18.5°C the warmer the day, the less the difference, and showing 13.4°C outside at the moment.

There must be air movement possible as the diagrams show, but with such varying temperatures within the room, this must be very slow. In the old days, the cold air entered the room under the door, and hot air left up the chimney, I did see one house with vents by the fire so combustion air was drawn into the room local to the fire, but this was not very common.

Today we have extractor fans over the cooker, but no ducted air from outside to replace it, and as said any electric power used, ends up as heat in the home anyway, the largest loss of energy is likely the gas cooker, as one needs extractor fans with the gas cooker to remove the waste products from burning gas, in the main water, with electric we only run the fan on a hot day to remove the heat, and since induction hobs put less heat into the room, not needed much.

I have plug in monitors, three in all, and I have tested most plug in devices, plus a meter which does whole house, provided years ago by Scottish power, but that meter too general and the CT is too big to fit inside consumer unit, and the others only work with plug in devices.

So alerted to a fault freezer, and also realised how much a Sky box costs as it powers the LNB 24/7 to pick up program changes, and I use them to see when the car battery has finished charging and if my home brew is reaching set temperature, but in the main they are toys, one even records the power factor, but what is the point in it all.

Simple fact, if I don't need the device unplug it, and if I do need the device, I am going to use it however much it uses.

I will look at one item the fridge/freezer, when new we are told the annual energy consumption, around 250 kWh, so divide that by 365 and we have 684 Wh per day, the manufacturer always seems to under estimate what it will use, so 700 Wh per day is around what we expect. So we stick the energy meter on it, and it shows 800 Wh per day, so what are you going to do? To re-gas will likely cost £100, and it may not be short of gas, the insulation may have started to fail, so costing 36.5 kWh per year more than it should, so what is that in money? Around £10 so not worth doing anything.

Now at 1560 Wh per day, that's more of a worry, motor when running used 65 watt, so clearly not turning off, so is the unit needing serious work, or is it simply the thermostat failed, so next step is measure the freezer temperature, if -18°C or higher some thing wrong with gas or insulation, if however -24°C it is not regulating temperature.

But where do you find a thermometer to check it with? Well -18°C is freezing point of brine, so mix some salt and water heat it so sure saturated, then put it in freezer and see if it freezes, if it does likely thermostat problem.

So I have shown one use for the energy monitor, but would it not be far easier to buy a thermometer instead, or just try freezing brine? So as said the energy meter is a toy.

 

[robinbanks]

that might be the theory, ours was under the window, with the curtains closed the warmest prt of the room was behind the curtains next to the cold glass where heating loss is greatest.

Yeah, you're supposed to tuck the curtains down behind the radiator and have their thermal/air trapping qualities isolate the window from the room, rather than use them to create a small, warm pocket right next to the thermally worst part of the room..

 

[robinbanks]

I'm AMIEE

Hi Aimee! Always good to meet fellow tradeswomen

I need to measure the time each element is used for

That's the part where you have something like a Raspberry Pi sampling at regular intervals over a period, no? Of did you literally mean you want to profile each individual heating element?

 

[ericmark]

The question is, once you get the information, what will you do with it? Unless the info can save money or energy what's the point? Energenie do make a CT which can connect to my PC and record the time as well as power which is what the plug in device does, but can't see how it would save me more than £10 a year, so what's the point?

 

[pcaouolte]

No it isn't. A washing machine, fridge, in fact anything with a motor will show a inflated reading.

We were discussing cooking methods, I would expect an electric oven to have a power factor close enough to 1 that it makes no difference to the task in hand. For items that have a plug it is easy enough to get the PF as well as the current. In fact my CT setup also shows me the power factor.