207 replies to this topic

[Duncan Werner]

So I'm pretty sure we've figured this out. It's basically what I described above, except for the dodgy part about environmental temperature. Here is what is happening:

(1) As I said above, it's a small amount of water boiling at the top of the heater. This happens when the heater can't transfer heat into the water fast enough. There's some steam generated as well, but this can be hard to see.

(2) Heat transfer is more efficient when the water is at lower temperatures. It's easier to heat up water at 25C than 63C. That's also why it takes longer to heat from 40C - 60C than from 20C - 40C. And it takes longer when there's more water.

So the reason that it was happening is that the water temperature was already pretty high, and you had a lot of water. I'm guessing that that cooler is 16 quarts. When it was trying to heat up to 63C (or maintain that temp) and it had to run full power, heat transfer was less than efficient so there was some residual heat, boiling the water at the top.

When the power level dropped down, it was able to transfer more efficiently - hence no boiling and quieter. We normally don't notice this because while it may happen briefly at high temperatures, it's only temporary while the heater is running at 100%. In your case apparently there was more power required to heat the water (and probably the cooler insulation as well) so it ran making noise for some time.

I can't quite account for why your stopping and starting made it go away - that might have been a coincidence, but we're still tinkering. However while it might be annoying (sorry about that), it's not going to cause problems except for additional evaporation.

One resolution might be to impose a limit on the heater of say 75%, but that would slow down heating so I'd rather not do it if we can avoid it. We will keep investigating.

---

Thanks again for the thorough testing and analysis!

[Chris Hennes]

I can't quite account for why your stopping and starting made it go away - that might have been a coincidence, but we're still tinkering. However while it might be annoying (sorry about that), it's not going to cause problems except for additional evaporation.

Well, it seems that the unit's logic to figure out how much power to apply was messed up: when I reset it and the unit saw that the water temp was perfect it settled itself down nicely, with minimal further noise (but also never having to go above three bars of heating).

When I used the unit again today in a much smaller vessel, again with water preheated mostly, but not completely, it again made significant noise whenever the heater was at three bars or above. I need to try it again starting with room temp water like I did the first time when it was silent, to see if it goes back to being quiet then or if I've done something permanent to it.

One resolution might be to impose a limit on the heater of say 75%, but that would slow down heating so I'd rather not do it if we can avoid it. We will keep investigating.

I really don't think you want to do that: 300W is already a bare minimum, and at 75% output mine still makes plenty of noise at the moment.

[Chris Hennes]

I need to try it again starting with room temp water like I did the first time when it was silent, to see if it goes back to being quiet then or if I've done something permanent to it.

I don't know why I bothered writing this when I could have just gone into the kitchen and done it. Thankfully, when starting from 18°C water back in 5 liters of water, even at full blast it is back to being silent. Which makes sense if the noise is due to boiling water at the heater, I guess, since we're nowhere near boiling. I'm going to bring this batch of water up to 65°C to see what happens.

[Chris Hennes]

Duncan, have you operated the unit much in particularly hard water? I noticed that my heater had gotten a fair amount of mineral build-up on it and I am guessing that it's just from the water.

[Blues_Cookin]

Ok, so far I have made four meals with the SideKIC, along with a couple food-less tests to get a feel for how it can handle pushing up the heat etc. Here are my notes so far:

What I like

• Price point rocks
• Water circulation is aggressive - it means you have to occasionally monitor your food bags or secure them to prevent them from blocking the intake, but my temp measurements with my Thermapen in four different positions in the bath all read within 1/10th of a degree C for an hour straight. Impressive!
• Software is intuitive and easy to run.
• Once at temperature, has no problem holding temp within 1/2 degree C, even with 4 lbs of (dry aged :-) ) steaks in only 9 L of water. This was in a simple rubber maid tub with no insulation and no lid. In a 15 L cooler, also held temp no problem with 2 lbs of sliced potatoes.

What I'd like to see considered

• Top Temp of 85 degree C - many starchy veggies need at least 89 C, so if the current 85 C limit is arbitrary, It would be great to see that pushed to maybe 95 C or so. (Can this be done with a software update??)
• The corrugated sleeve between the immersion unit and the controller is not very flexible - and is brittle enough to push the controller around. Would be nice if this was a bit more flexible and allowed you to place the controller where I wanted without the corrugated tube trumping my designs.
• The heater is not powerful enough to meaningfully HEAT water, though it is very capable of MAINTAINING temp. My tests at 10 qts show that it requires 10 min to gain 6 degrees C at 40 degrees C, but only increases the temp 2.2 degrees C in 10 min at 55 degrees C. You will definitely need to use an alternative source to heat the water bath to close to target temp - I quickly resigned to heating my water on the stove. However, this is not a major issue, I would rather heat the water separately than require a unit that cost twice as much simply because it included a more powerful heater.
• On a less important note, the length of the immersion limits the pots you can use. If there was a bit more depth, it would increase the options on the pot.
• Beeper when the bath hits the desired temp would be nice.

Overall, my initial impression is extremely favorable, especially for the hobby cook. I will certainly be getting a lot of use of my SideKIC, and have already recommended it to a few friends.

Edited by Blues_Cookin, 13 February 2012 - 09:58 PM.

[Chris Hennes]

Nice summary, Blues_Cookin, I think we're on the same page. Really, it can't be emphasized enough: the price point is sweet. Period. Yes, you can build the same device yourself for less. Minus the injection-molded plastic container that makes it look like an appliance rather than a science project. The Spouse Acceptance Factor is high with this one.

Have you done any work with it in an insulated container? I really think that with only a 300 watt heater, using an insulated, lidded container is key for the higher-temperature items. You can cook eggs and steak and chicken all day long in a stock pot, but if you want to cook veg, you need some insulation.

[sreeb]

I have an older lab style Polyscience immersion circulator. I think is has a 1200W element. It will readily boil water at the element if it is more than a couple of degrees low. I don't see it as a problem. If it is boiling water near the set point, then the coefficients may need a little tweaking although it may still work fine.

My rock hard SoCal water does leave mineral deposits. I suspect this is directly related to boiling water at the element.

I wouldn't be cooking any eggs in a bath with a circulator. One leaky egg and you will have an amazing mess. The design of the SideKIC looks particularly vulnerable and difficult to clean. If you must, bag the eggs in a ziplock full of water.

[sreeb]

What I'd like to see considered

• flexible and allowed you to place the controller where I wanted without the corrugated tube trumping my designs.
• The heater is not powerful enough to meaningfully HEAT water, though it is very capable of MAINTAINING temp. My tests at 10 qts show that it requires 10 min to gain 6 degrees C at 40 degrees C, but only increases the temp 2.2 degrees C in 10 min at 55 degrees C. You will definitely need to use an alternative source to heat the water bath to close to target temp - I quickly resigned to heating my water on the stove. However, this is not a major issue, I would rather heat the water separately than require a unit that cost twice as much simply because it included a more powerful heater.

The specific heat of water doesn't change significantly between 40C and 55C. You probably need to either use an insulated tub or lid to reduce evaporation.

I always use hot water from the sink to start (around 130F) to start.

I haven't done any higher temp cooking of vegetables though.

[Chris Hennes]

I cooked both lentils and carrots this evening at high temperature: without insulation or a supplemental heat source the SideKIC's heater had to work pretty hard just to maintain temp. I think that the product was clearly designed with lower-temp cooking of proteins in mind. You can use it for higher-temp sous vide (up to 85°C), but you're going to want to preheat the water and use a well-insulated container or supplemental heat source (a stove on low will do the trick, but also violate their "not for stovetop use" indication in the manual).

[Shalmanese]

I cooked both lentils and carrots this evening at high temperature: without insulation or a supplemental heat source the SideKIC's heater had to work pretty hard just to maintain temp. I think that the product was clearly designed with lower-temp cooking of proteins in mind. You can use it for higher-temp sous vide (up to 85°C), but you're going to want to preheat the water and use a well-insulated container or supplemental heat source (a stove on low will do the trick, but also violate their "not for stovetop use" indication in the manual).

Have you tried using an electric kettle to pour some heated water into the pot and then bailing out some of the old water if it threatens to go above the water line? It's an easy way to add some heat to a beer cooler style setup.

[Blues_Cookin]

Chris - yes, I did use a insulated cooler for the 2 lbs. of potatoes. Not an entirely fair container to measure the SideKIC's ability to heat the water temp as it is 16 Qts. However, it did a fine job of maintaining temperature once it got to 85 C. And agreed, spousal approval is key to happiness!

[dcarch]

Some pumps last not too long at higher temperature. They are all intended for fountain/aquarium uses.

Althought I think the unit is safe for general use, it will not be legal unless it is electrically grounded or double insulated for UL approval.

dcarch

[Duncan Werner]

Althought I think the unit is safe for general use, it will not be legal unless it is electrically grounded or double insulated for UL approval.

Well this is very serious. I believe we are fully conformant, but I'll check with our consulting engineer to get an official position.

Some pumps last not too long at higher temperature. They are all intended for fountain/aquarium uses.

Actually these are intended for hot water/coffee machines, so they're rated 105C. (Edit: that's not to say that they will live up to the rating, but that's what they're rated).

Edited by Duncan Werner, 14 February 2012 - 08:56 AM.

[Chris Hennes]

Have you tried using an electric kettle to pour some heated water into the pot and then bailing out some of the old water if it threatens to go above the water line? It's an easy way to add some heat to a beer cooler style setup.

In my cooler setup, once the water is at temp the SideKIC has no trouble at all maintaining the temperature, I haven't needed to supplement it. But I'm using a decent cooler with a custom styrofoam lid, so losses are kept to a minimum.

[Duncan Werner]

Althought I think the unit is safe for general use, it will not be legal unless it is electrically grounded or double insulated for UL approval.

So here's where we are with this: I think the machine is safe, but it's likely that our power cord is underspecified. That is, it should be better insulated. Rather than fix that, however, I think we'll follow dcarch's line of thought and fully ground it.

To that end, we're going to put the machine on hold for a week while we can refit some inventory. We'll figure out how to handle the existing machines over the next couple of days.

Let me just reiterate that I think it's safe, but this is the right thing to do so we might as well do it now. Particularly for people who don't have GFCI in their kitchen, it's better that we err on the side of being extra cautious. Thanks to everyone for the kind words here, I'll update when I have some more information.

[Chris Hennes]

Particularly for people who don't have GFCI in their kitchen, it's better that we err on the side of being extra cautious.

Kitchens without GFCI scare the hell out of me. Nice move on adding the grounding line, though, that will be a good change.

[dcarch]

"---So here's where we are with this: I think the machine is safe, ---"

I agree. Let's put things in perspective:

The pump I think is meant for submerged use and so is the heater, therefore the device is logically safe.

However legally, ( I am not a lawyer) I think when you put them together into some kind of new unique use, that may be a different story.

Perhaps instead of a plastic injection molded case, what about a stamped metal case? you can just ground the case?

dcarch

[Chris Hennes]

Perhaps instead of a plastic injection molded case, what about a stamped metal case? you can just ground the case?

Sure, and add $100 to the price tag. Injection molding is much, much cheaper. Fundamentally this device is a glorified coffee maker, grounding the power supply is completely adequate.

[cbread]

Well, just getting over a cold which took me out of the game for a while. Now firing up the SideKic once again.
This time with a bagged piece of beef rather than a food-less trial run. Just a zip lock bag. Seems to be working fine. It will be a while till I could justify a chamber vac.




Once again I'm impressed with how easy it is to use and find my earlier critique a bit too sharp. It seems to run a couple of degrees below my thermometer readings, but it's steady and I can adjust with no difficulty.




The controller unit is easy to comprehend and dead simple. I like it.




The whole thing is reassuringly undramatic to use. Temps seem very stable and consistent all over the cooking vessel.

It's just plain easy to use.

I can't wait to do a long slow tough tasty cut for the first time. Tonight is just a tender quick cooking steak and since it has the oddball title of "Sirloin Junior" at the bucher's I really don't know the proper time so I'm just winging it two hours 135F and then I will sear it.

Off to do veggies...

Edited by cbread, 18 February 2012 - 04:37 PM.

[rotuts]

cbread

you are on the right track with the 'beer cooler'

you do not need nor want a chamber sealer

you want a 'sealer' so that with 'pre-heated' water in that cooler you can do 10 or so packets

for the same amount of prep time

and the same amount of energy

Happy Sous Vide !!

[Blues_Cookin]

Bad news to report today. Had a pork shoulder in a insulated 16 qt cooler with an improvised lid starting at 5:30 last night. Held temperature fine all night, but this morning started slowly losing temperature. I figured the drop was equivalent to how fast the cooler would lose temp if there was no heater at all (10 degrees F per hour). Tried resetting it (pressed "Stop", unplugged for a few minutes and then plugged it back in and pressed "Start"). No change in behavior, continued to lose temp.

I checked the water level which was fine, and also made sure nothing was impeding the water flow, and that was ok as well.

I took the circulator out, let it sit for half an hour, and now have it in a small 2 qt sauce pan with the water at 62 degrees F. In 30 minutes with the heater indicator at full orange, it has only gained 2 degrees.

Any ideas?

[Duncan Werner]

That's terrible, I'm sorry. Honestly I don't know what might have gone wrong - although I don't think there's anything you could have done which would make this happen. It was probably defective hardware. Can I replace it? We have the rev 2 machines ready starting next week. I'd like to have a look at and see why it stopped working.

[dcarch]

I don't suppose you have an “amp clamp” electric meter to measure how much power the unit is drawing.

Typically a resistive electric heating element is either working or not working. In this case, if the water temperature actually was rising in the two-quart sauce pan meant the heater was functional.

What could be the problem?

Possibly the solid state “relay”, which is, as I understand it, a non-ZC triac. The digital control from the electronic logic circuit may not be delivering the correct signal to the triac, causing the heater to underperform.

dcarch

[Duncan Werner]

Typically a resistive electric heating element is either working or not working. In this case, if the water temperature actually was rising in the two-quart sauce pan meant the heater was functional.

If it just rose 2 degrees, that's probably coincidental, I don't think it's working. As you say it's almost certainly the controller. If you power cycle it, there's no state preserved for the PID so that would suggest it's hardware - either a component failure or faulty board connection.

[Blues_Cookin]

Duncan,

I was also thinking the temperature rise could simply be the pot coming up to ambient temp. Should I return it directly to you guys? Would be happy to replace with 2.0 :-)

Thanks

Tom

[Duncan Werner]

Let's talk about it off-list, I'll send you a note.

[dcarch]

To Blues_Cookin, Which electric outlet did you plug in the SideKIC?

Some refrigerators can send a big electric surge/spike when the compressor kicks in because of the motor is an inductive load. That can kill some sensitive electronics.

dcarch

[Duncan Werner]

It's an interesting thought. If we get it back in the lab we can check that out. There aren't many components directly on the line, and there's a MOV on there which should shunt surges, but the best way to know would be to look at the parts individually.

[dcarch]

"----and there's a MOV on there which should shunt surges, ---"

That's a good power supply circuit design.

dcarch

[cbread]

MOV???? You electronics guys...

I have to ask, what's a MOV?