Pylontech fan cooling setup

[Jatho]

Hey guys

So I've been busy during lockdown installing my Victron system with the help of Jaco from Go-Solar and what a breath of fresh air it has been dealing with him he's super helpful and knowledgeable and always happy to offer advise.

Anyhoo, I'm taking delivery of my Pylontech batteries tomorrow which are going into a 15U wall mount cabinet installed in my garage, in winter the temps will be mostly ideal but in the heart of the Cape summers the temperatures get up to around 39 degrees in my garage, not terrible but also not ideal so I want to integrate some smart cooling.

I've configured a nodemcu with a relay and temp sensor which I'll mount inside the network cabinet and have setup an automation in home-assistant to switch the fans on when the ambient temperature is above 25 degrees so my question(s) which I suspect will draw a lot of varying opinion is the following.....

1.       Is 25 degrees a good start range for the fans to kick in? I've got it set to switch off at 23 degrees although I think this is mostly a non event.  

2.       In terms of mounting fans, I know (think) ideally it would be best to mount some fans at bottom blowing in and then at the top sucking out but the fans I've got don't seem to have huge sucking power although they will make a difference I suspect, so really just looking for some input / advise from guys that have possibly done this type of thing. I'd prefer not to run them 24/7 they pull a lot of dust and need ongoing maintenance.

Thanks in advance......

 

 

[GerhardK83]

22 minutes ago, Jatho said:

Hey guys

So I've been busy during lockdown installing my Victron system with the help of Jaco from Go-Solar and what a breath of fresh air it has been dealing with him he's super helpful and knowledgeable and always happy to offer advise.

Anyhoo, I'm taking delivery of my Pylontech batteries tomorrow which are going into a 15U wall mount cabinet installed in my garage, in winter the temps will be mostly ideal but in the heart of the Cape summers the temperatures get up to around 39 degrees in my garage, not terrible but also not ideal so I want to integrate some smart cooling.

I've configured a nodemcu with a relay and temp sensor which I'll mount inside the network cabinet and have setup an automation in home-assistant to switch the fans on when the ambient temperature is above 25 degrees so my question(s) which I suspect will draw a lot of varying opinion is the following.....

1.       Is 25 degrees a good start range for the fans to kick in? I've got it set to switch off at 23 degrees although I think this is mostly a non event.  

2.       In terms of mounting fans, I know (think) ideally it would be best to mount some fans at bottom blowing in and then at the top sucking out but the fans I've got don't seem to have huge sucking power although they will make a difference I suspect, so really just looking for some input / advise from guys that have possibly done this type of thing. I'd prefer not to run them 24/7 they pull a lot of dust and need ongoing maintenance.

Thanks in advance......

 

 

Hi Jatho

I would only mount fans in the top of the cabinet sucking hot air out of the cabinet. On the inlet side I would put a filter to filter out dust. A fan which suck air out of an enclosed area is much more efficient than a fan which blows air over an object.

The filter does not need to be a filter which is specially made for the purpose I would look at Fram or GUD air filter or pollen filters that you can buy @ a car spares shop. Fram and GUD have online catalogues available where you can search according to application and size. http://www.fram.co.za/index.php/filter-query or

 http://www.gud.co.za/index.php?option=com_wrapper&view=wrapper&Itemid=109 or you can download the GUD catalogue with pictures and install it then you can view the filters as well.

What I would also do is use multiple outputs of the nodemcu and a couple more relays and switch more fans in if the temperature rises in stead of all the fans running even at a low temperature.

If the fan cooling is not sufficient I would look at the fan which they use for the blower in a car with the resistor pack then you can also control the speed of the fan according to the temperature inside the case or an electric radiator fan that you also buy @ a car spares shop.

Do not be scared to alter or modify the cabinet to suite your needs, after all you want the batteries to last as long as possible and keeping them cool @ 25 degrees Celsius would be a good idea to extend their life by a year or 3 or even more.

I would also look at insulating material to insulate the sides of the cabinet on the outside, a good insulating material that I found are these carton trays which they use for the eggs (as per the attached picture). 

GerhardK83

[Jaco De Jongh]

12 minutes ago, calypso said:

As much as a like Home Assistant and such, is it worth the effort? I would just get AC fans and leave them on 24/7.

Hi, the home assistant is great combined with the Modbus service of the Venus. I do so much control using HA in combination with Venus. Its truly worth the effort and well worth exploring. 

[Jaco De Jongh]

47 minutes ago, GerhardK83 said:

What I would also do is use multiple outputs of the nodemcu and a couple more relays and switch more fans in if the temperature rises in stead of all the fans running even at a low temperature.

I think Jatho might be unaware of how nice the Venus with all his inputs and outputs are. He will be able to use the Venus itself to do most of that he needs, without any external NodeMcu other device. 

[Jatho]

Hey guys

Thanks for all of the input, Jaco actually gave me a call last night when he saw the post and suggested using the Venus GX I have to handle the temperature control, I should have put 2 & 2 together it has temperature sensors as well as relays

[jykenmynie]

On using fans to cool the system: Can’t fans just cool to a minimum of ambient (It just moves air around)? So if it is 35C ambient, you can’t get the batteries colder than that unless you use an AC like compressor (or more exotic cooling) so worrying about when to shutdown the fans seems to not really be a concern. You probably want to automate and never worry about it? In which case, just set it to shut down on a reasonable temp inside the batteries’ operating range.

What you could do to prevent dust buildup is to get some dust filters and create a positive pressure inside the case (all fans set as intake). Then you wouldn’t run the risk of pulling more dust in anywhere but at the fans’ dust filters.

If you use good quality fans, they can run for years without giving issues. My computers are running 24/7 (though often idling) and at least the CPU fans would be spinning all the time. Never had a fan give in on me before the computer needed replacement anyways. However, I always over design my cooling, so they spin at a very low rpm, typically around 600.

[___]

1 hour ago, jykenmynie said:

So if it is 35C ambient, you can’t get the batteries colder than that

Yup. But Newton's law of cooling says the rate at which the battery cools down is proportional to that Delta, so I suppose that's why you do it... you want to get the heat out of there and ambient air in, because that gives the greatest rate of cooling. But I also remember Google once stopped air-conditioning their data centers (or at least, not to very low temperatures) because they found out the AC costs more than the cost of hardware failures

Otherwise, absolutely correct. You'd have to use an AC if you really want to keep them cool on a hot summer's afternoon.

[Jatho]

7 hours ago, jykenmynie said:

On using fans to cool the system: Can’t fans just cool to a minimum of ambient (It just moves air around)?

I think its more about assisting with exhausting the hot air out of the cabinet to make way for cooler air, I'll do some playing around with it in the summer months for now the cabinet is adequately cooled. 

I could probably just leave the fans on permanently but if its running as it has been at around 19 degrees its an unnecessary waste of power albeit low amounts, if I run it on some sort of smart control I recon they'd be on for around 20% of the year so its worth the effort, I'd like to streamline my consumption as much as possible.

 

[jykenmynie]

18 hours ago, Jatho said:

I think its more about assisting with exhausting the hot air out of the cabinet to make way for cooler air, I'll do some playing around with it in the summer months for now the cabinet is adequately cooled. 

I could probably just leave the fans on permanently but if its running as it has been at around 19 degrees its an unnecessary waste of power albeit low amounts, if I run it on some sort of smart control I recon they'd be on for around 20% of the year so its worth the effort, I'd like to streamline my consumption as much as possible.

 

Yup exactly, you need to move the hot air, but you can expect it to run quite a few degrees above ambient probably even passively. Not sure about the heat generation of batteries, but during the daytime in summer you probably aren’t using them a lot so they probably don’t create too much of their own heat that you want to move.

Give the positive pressure thing a go, if you want. I’ve hears some good things about it with regards to computers. Same principles would apply. I haven’t tested it myself, because I’m much more OCD with noise than with dust, and don’t spin my fans fast. On the batteries, noise probably won’t be an issue, so spin them at half their rated rpm and you’ll get good mileage, at least in my experience. Just remember, if you are ever turning them off for extended periods, you’ll start to get dust buildup.