Basic insulation versus non insulated container stats..

Following one method / material however you get the gist, precisely why I insulate, less grid stress, less cost, less environmental damage, lower bills for cooks, faster heat up time, less element cycling through retention.

The grist of the info is this…

Energy efficiency

I ran a series of tests using a TP-Link Kasa Smart Plug to measure energy expenditure. For each test, I brought 7L of water up to 66°C and then started measuring after the water reached temperature.

Wrapping the container in blankets is a bit annoying (and ugly) but it uses less than half the energy as when unwrapped. If you are doing long multi-day cooks, it is definitely worth making sure your container is insulated. For example, a 48-hour cook without towels would take 7.2 kW, whereas it would only take 2.9 kW with the towels.


Good data. I have a dedicated cooler I use for sous vide.

Yeah, I have a few, i’m just afraid that “insulation” is too low a priority for many folk, these stats (if read) may wake a few folk up, the anova has been heavily sold on the pan-o-water principle with not enough in your face detail as to marketing it as a LOW energy cooker following a simple principle, or the cooler principle (of which coolers differ in terms of no / some / crap insulation, marketing means that a non insulated “cooler” can be marketed as one based on inside / outside temps with little to no data, commonplace crap sold at music festivals as “dual wall” (an inner moulding inserted into an outer moulding) …in fact I have seen plenty of coolers sold but not ICE, / ICE BLOCKS.

Low energy cooking is another string to a stick wands bow if utilised properly (& an add on for the container market) …look at the air fryer market for instance.

Measured data, of which there is not much in that link, but plenty of difference between insulated energy use versus uninsulated should be eye opener enough.

One of my anova’s was tripping out when I used an energy meter with it, I really need to try again with a variety of containers & insulating material specs.

My gripe with the insulated coleman coolers I have (not cheap in the uk) was the energy p155ing HOLE & lack of concern with solid product design around the can insert points on the lid which became thermal chimneys for letting cool out / heat in etc due to no barrier being present, which I had to bodge fix myself. (& it made a big difference to retention / food safety potential.

2.9 kWh hours energy consumption versus 7.2 kWh (kWh being the correct usage of terminology)

It’s a given that using an insulated container will allow you to heat more efficiently and hold temperature more efficiently. How much, while nice to know, is rather irrelevant to me. I’m not going to go out of my way to add additional layers of insulation to my sous vide tanks.

I already utilize commercial neoprene insulation blankets on the exterior of my tanks and also utilize a lid on my tanks. Could I buy bulk neoprene and make it thicker? I’m sure I could. Would it save $$$'s over time. Definitely. Will it save enough to make it worth the trouble? That is the question that would bear answering.

Happy sleuthing!

Neoprene gets stinky as it gets wet & dries, use on sigg bottles years ago bore that one out, it’s good & figure hugging but not my favourite material due to it being somewhat specialist material not off the shelf (though ebay makes this simpler nowdays, the amount of folk with a sewing machine capable of stitching properly various materials has gone down, making it out of reach for many, unless commercial scale production is utilised for an unknown market size.

The location of an SV in a kitchen may draw in odours & stains which result in less mindful folk simply trashing it (not having a clue how to wash, dry, maintain neoprene) …it’s location close by the pan a likely influencer.

(I use neoprene on my grainfather brewing kit, it helps but is overpriced in that instance)

The malaise in many an approach is not knowing to any degree, there is a law of insulation cost versus performance versus point of diminishing returns.

The common phrase for stuffing insulation in voids being “something is better than nothing” yes it is, though knowing may affect material choices.
Years ago I insulated my bath void in the same manner, in a hurry, these days I’d employ a better thought out slab layer approach & side wall infill, suffice to say the bath did stay hotter with less heat leaching & top ups necessary.

You need to know the insulation value of the material you are using.
From there you can make a call as to effort versus payback (or even the environment)

The type of insulation across the various types of cheap polystyrenes then beyond into the foil faced insulation board material is there to be seen if people bother to look (& in many house renovation skips for the taking)

Phenolic foil faced is my favourite for cheap diy improvements.

Finding for comparison both EPDM & neoprene insulation values is tougher, & best taken from the manufacturer, though is out there.

Point as explained before is that folk who insulate their pots to a decent degree are few & far between, look at the energy savings potential in operation across the board thus, if a switch were made by the majority.
In the uk we have access to the half hourly carbon cost of our energy as various forms are utilised to keep the lights on, this helps those with a damn to give ascertain simple things like when to turn the dishwasher on (typically set to 1 am …low carbon / energy cost time) the same principal can be effectively applied to savings with a bit of insulation for most folks cooking containers

No idea if North american grid system displays the same value types for general consumption?
Here is one of ours…

But if you put 2+2 together with regards to reducing your overall carbon footprint, then an insulated sous vide cook makes sense as a contribution to that low carbon intensity effort, …without going to extremes it is likely close to a modern day hay box cook as modern society will get, ie it can be very efficient without any discernable effort or self flagellation with a hair shirt, also, therefore good for off-grid potential, cabin / van camping where energy is limited or needs a modicum of frugality in use.

That makes it excellent for anyone simply trying to keep the bills down in general, (ukraine war / russia’s energy war has for europe meant that oven’s are in the main turned off, we are now I estimate 2 years into not having used ours at home, instantpot / airfryer combination, sous vide wand, single hob use & a microwave are what we use to cook with without even a pause for thought, many others are doing the same but without the advantage of a sous vide.

Do any coolers actually list thermal performance specifications on their products based on insulation used & walls? …few & far between I imagine yet essential knowledge for assured performance under duress, this often shows up the commercial BS output of a marketing dept who big up a product but haven’t a clue as to base performance unless they get the numbers from elsewhere / conduct there own tests & promote the results compared to that of the competition, but likely not given that most folk remain oblivious even if a cooler is a mainstay of so many homes, the thermal performance of a fridge / freezer that is going to sit in a home for a decade, quietly turning over.

Many folk in the world are sadly not even aware of the differences in insulation between XPS & EPS in general let alone when buying an insulated drinks bottle or similar that is used across seasons, they just go on the word “insulated” for which a gap between layers of construction material is in effect “insulated” …but by how much, & that is the annoyance that makes the link & subsequent energy reduction usage over a long cook stick out.

When you lay down insulation in a room, building or whatever the perception is that of a permanent layer that saves money assists comfort across climates & seasons for decades to come, so to measure the cost in materials alone (ie without payback time) is wise to be avoided.

If you construct via offcuts something useful in SV tank instances yourself then the cost is likely nothing but time & sealing tape (for instance) for the rest that is why the energy reduction is there as a starter for ten for the various forms of materials around,

Price of 7 units of energy in your area versus 2.5 (e.g) can be calculated into short cooks etc, as ever it depends on how little or how often the item is used (sv stick) …likely here that is 3+ times per week for many old hands.

But, I’m not going to wipe arses for folks.
I do have various energy monitors but they are on long term use or I don’t agree with intrusive requirements of the software to a phone (for instance) thus the above link gives an insight in this area.

I’ve just moved my SV rig, & the temperature it is able to hold with a wall behind it (less draught)!? means it is in my estimation holding better temp without anything bar counter top reflective insulation, it is holding another 2-3c (estimated) better than before when in cool down.
Thus I am in the middle of cutting & sealing a new mix n’match of PIR foam foil sheet insulation offcuts which won’t be even thickness all round, but plenty is better than some.

Base is still 60mm PIR foil faced board (the original piece)
Side wall 1 is 100mm.
Rear wall (with cut outs to allow for serving hatch (which I should have simply removed the handles) is 50mm.
Side wall 2 anticipated 90mm PIR foil board.
Front wall will be 50mm.
Top sheet will be 50mm (overlaying the silicone cover) … I have no idea how much cooling is required by the head unit electronics, so will not take it any higher lest it restrict the units ability to self regulate & stress components within the head unit.

Gaps around the pot will be filled with rolled insulative packaging.

(In essence what I am doing here is the same as how I have filled out the cupboard space where our indirect hot water tank is located, but on a smaller scale)

I am trying to resist buying that Ikea 10 litre tub people have converted, in which case another insulation hack job is imminent.

NB whilst I have dedicated insulation saws (cheese blade type) for 100mm thickness PIR foam foil insulation boards cutting & trimming, you cannot beat an Ikea steak knife, it really excels, wish I had used that years ago, doubtless sped my cut & trim time by 50% compared to regular knife assortment used.

Q. Why isn’t it all even thickness?
A. Custom fit to a back corner of the kitchen room, whilst re-using the original base protecting insulation, due to the amount of offcuts this can be swapped out if needed.

(Insulation boards are all edge to edge sealed with aluminium foil tape to keep the gases used in the foam sealed in where possible, prevent foam dust, not good for you, migrating onto work surfaces, into food, being ingested et al)

Whilst it is not neat, the energy savings are there to be had.

Considering how crud the cooler wall foam has proven (ie lack of proper fill) i’m of the opinion that the foam is cheap stuff that does a job, no stated u-values, so, “meh” but better than nothing.
My wife would kill me if I had a cooler in the kitchen 24/7 thus an impossibility.

My other dilemma is when remembering about all the crud in plastics which is why I tend to use a stainless steel pot, I deal with remaining aware of prolonged times at high temps & avoid those wherever possible, but the whole amazon polycarbonate unit holding heat for hours is another qaundry that stops me finding a better fit within a kitchen corner (& hijacks my spare instantpot inner)

Anyone know of a 10 litre oblong s/steel lidded container made for the typical SV wand that doesn’t make you wince at the price?

For about five years i have been using this built in solution. I can use my bar sink as a builtin sous vide container. I need to stress that my sink is clamped under the counter and not simply glued. I insulated the sink with radient reflective wrap. The cabinet underneath stays cool. The two piece top is thick synthetic wood. Its a tight fit so very little heat or water loss. After water cools i just drain the sink. I usually use this for shorter cooks so im not tying up the sink for a couple days. Over night is ok though. For longer cooks i use a cooler with custom foam board top with a cut out for the APC. That way I still have a cooler with a lid to use as a cooler

That’s a nice looking set up, we live in the drought prone section of agricultural countryside within the uk, I could not bring myself to pull the plug after a short cook but I get why you do.

I tend to fill up my Anova vessel from water standing overnight run off into a 2 litre bottle (typically 1 litre per time) to prime the kettle for a fresh cup of tea, this keeps the energy & commodity use down,

I must admit to toying with the idea of cut outs for mounting both an anova SV & an instantpot in this manner, or simply a bucket mount (like for horses in a stable to eat at a raised level) that would mean It was not so high for the wife, daughter (& myself) …I might get there one of these days with a foldable mount piece of ironmongery, thanks for showing yours it is insightful seeing it done properly.

Hey, thanks! This is great info. I was going get a cooler or some sort of insulating container but at 12 cents per kWh in my area it’s definitely not worth the cost and effort. Most of my cooks will be under 5 hours so that’s just 5 cents per cook. Even a 48 hour cook is only 50 cents difference.

Mine is (as stated) for the energy bill cost as well as the carbon mix cost, the environmental damage is something I am as keen to avoid much like I don’t want to suck on tail pipe fumes whilst in traffic (car or push bike) …little things, chipping away at the bigger problems involved with life & meat consumption (of which beef is a heavy hitter of carbon cost)

Much like if I fly to Geneva (switzerland) with my family the carbon cost is several hundreds of kg per person of carbon emissions, by comparison a bus with a bunch of other passengers works out at around 28 kg per person to get to chamonix in france, so a bit of basic lifestyle juggling here & there keeps me sane without drama visiting the fast melting glaciers & at risk snow pack.

Even if the kWh energy cost were free i’d still do it frugally, it all has an impact somewhere down the line (transmission line losses, generation types based on season, national requirements, …more nuclear waste piles that no-one wants getting more expensive, & ditto the cost of tearing a nuc plant down & processing the crud that go’s with it. (ends up with more taxes on lifestyles & products purchased)

We all have to do what we think is right. In my case I don’t know if I’ll use it more than once per week (new user) so the carbon footprint of a new cooler might be greater than the extra carbon of no insulation. I’m still using my oven and stove, and once per week I wheel out my big smoker and do an all day smoke of a pork roast or some beef. If I find I use my SV a lot I’ll probably look into an insulating solution.

Beef is a heavy hitter for carbon? I didn’t know that. And here I just brought home a quarter beef (146 lbs) on Monday. Oh well, I guess I’ll take solace in the fact that it tastes amazing.

You know you could just skip that trip to Switzerland all together…

Nah, our lifestyle elsewhere allows for that, especially since buying a new BEV its just a 12 hour drive away.

1/3 of our annual electric will shortly come from a wind turbine investment (built overlooking / annoying a donald trump golf course in Scotland) starting imminently, & we have solar plus battery upgrade coming soon, pretty much negates our energy usage including driving 2 BEVs not including the fact we are already on a renewables tariff for energy.

The battery bank means that when not self producing you can generally choose to import when prices are low & optimise through storage compared to high demand tariffs for peak times, again benefitting times when you are cooking with a minimal draw such as insulated sous vide.

Chicken is the western commercially raised meats lowest footprint (depending on how it is raised fed etc) …any corn grain animal like a lot of your beef cattle is fed to induce faster growth is even higher in footprint, it is blander in taste to europeans typically grass fed beef but it is what they sell you in many markets unless you source the other yourself.

I come from a farming family so it has been an interesting journey of the generations, I still enjoy the odd steak but my meat consumption in any large amount is likely once per week at most.

As for coolers, yard sales or being a “tip rat” at a recycling facility, or in the uk we have “freecycle” which is useful for things other people are disposing of, my other weber, coolers, insulation all sorts have come from there, a good resource.

(also good for home made home brew set ups in a variety of ways)

Today I ran my Anova SV through my energy meter to see how much I was using.

First up, I was experimenting with cooking eggs and trying to figure out the settings for eggs how I like them…with runny yolk. I ran the SV at about 146F for 45 minutes after warmup, then 148F for 45 minutes using the already warm water.

Following that I cooked a beautiful sirloin steak at 140F for 2 hours, with water starting around 120F.

I used a this stainless steel pot with no cover and no insulation. Ambient temp was 71F. With those parameters, I used all of 0.7 kWh, for a cost of 8.4 cents. More than I expected but still not enough to be worry about.

Interesting, thanks for posting, how many litres were you heating? (as 45 mins pre-heat seems excessive unless you wandered off & forgot! …like I too frequently do.

I did 30 mins cook 2 days ago, the water is still cooling (not quite at room temperature yet)

This is only partially insulated (forgot, busy with other things, lazy / stupid) the cost per kWh here is around 40pence per kWh so if you convert that into cents likely it would likely be an influence to improve it somewhat.

Using alexa converting pence to cents that is around 50 cents at current conversion rates give or take.

Currently i’m still using my s/steel pot as described above.

There were probably 4 liters of water in the pot.

The 45 minutes was AFTER the warmup. Sorry I didn’t make that more clear. The sequence was:

Initial water temp - 105F/41C (I used hot water from the tap but didn’t wait for it to get fully hot before filling the pot)

  • 10 minutes warm up time, estimated
  • 45 minutes at 146F/63C for the first egg experiment
  • 45 minutes at 148F/64C for the second egg experiment (my preferred result)
  • unknown amount of idle time
  • 5 minutes warm up, estimated, from 120F/49C
  • 120 minutes at 140F/60C for our steak (which turned out wonderful, btw)

kWh measurements were taken with my “Kill A Watt” model P4400 power meter

I did end up buying a silicone lid with a cutout for the SV, hoping it will dampen the audible whine but it will help with energy efficiency as well. You are correct, 50 cents for that cook would motivate me to insulate the pot better. I may anyway, though nothing elaborate.

Ha ha, no worries, I’m the edit king for attempting to fill in missing info upon re-reads, easily corrected compared to an overdone steak eh!

The tight fit will alter whine note, if it is close fitting & if there is a dampener from the pot to the kitchen surface, cork is neat & insulative, there may be a stash of wall tiles stashed away from the 1970’s & 80’s that never got thrown to play with, it’s pretty flexible should you want to play around & test yourself as a wrap.

Where mine is gradually tearing (I cut mine based on the originals removable plastic jet director / impeller cover) I will pad it out with something that doesn’t add to the sound, it’s been years in use & hardly a problem, likely an 8+ year lifespan before needing attention in my estimation (I did buy 2 when on sale as is)

I also spread the “pinpoint” with soft plastic & foam to help shift / dampen at the clamping point which also helps general grip of the newer clamp design, never really tested it as to noise / vibration reduction properly.

Must have been some chunk of cow steak, (context likely already written, but bears repeating for skim readers coming years later) …for a typical uk supermarket steak the anova app is USA orientated, & thus cook times / thickness are very different animals.

40-45 mins SV for atypical steak fare here unless it is advertised for fathers day steak “meat sweats” excess in which case your times are likely spot on (I have never eaten a steak that size myself)

With that lid, …not that you need telling, see that measured difference in that heat up & temp retention time.

A thought just occurred to me…any heat that escapes my SV setup ends up adding heat to our house. When you consider that, the actual cost for me to use my SV setup uninsulated when our furnace is on as it is actually less than stated since that energy “wasted” is dispersed into the room and use of our furnace is offset accordingly.

Granted, the difference is furnace run times is probably negligible, but still…it’s something to consider. Running an uninsulated SV setup it the summer is different equation, however.

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But escaped heat from a pot of water is mostly water vapour, (& plasterboard is a sponge)
IF lidded it’s different & IS heat (a mini thermal storage unit of sorts)

To really get to grips with it / what it does in different seasons you’d need the use of a thermal camera.