Who's fresh air cooling your equipment and how are your temps?

[hwy17]

I commissioned my system in April, so this is my first summer. I have an XW+ and MPPT 100 600 in a utility room with 2 external walls and no insulation, imagine basically the temperature of an unconditioned garage with the windows open.

My intention, so far, is that I will only provide ventilation and not air conditioning. And so far that consists of 2 open windows and a 120mm exhaust fan that sits above my equipment's exhaust, to try and suck that hot air out of the room.

Currently at 1pm, 89f/31c outside, inverter is pulling 4.3kW, and intake air temperature at the bottom of the inverter is 93f/34c.

It feels disconcerting, the body of the inverter is hot, and it makes me want to jump to add more ventilation. But, there's only a 3c difference between outdoor and indoor temps so what's more ventilation really going to do without cooling.

Doesn't help that I understand internally this inverter's got a paralleled pair of maybe 4awg wires between the fets and transformer primary that are pulling like 150+ amps under that load! But I'm not supposed to worry about that, those are internal wires that follow chassis wiring rules, and they have active chassis ventilation running over them.

I'm still continuing as planned, but I'm going to be operating closer to my inverter's derating charts. In a stronger heatwave of 104f/40c+ pulling more like 5kW for A/C I could even be looking at violating the threshold. So maybe I do need to start considering a window A/C backup for that event.

 

[ksmithaz1]

I'm stuffy, er fresh air cooling all my stuff. Highest temps I've seen ~ 130F. I have a big fan, equipment is in a storage room off the garage.

 

[B-Mod]

This is the reason I put my equipment in my basement, everything is cool all year long, never hot, never cold, just the right temp. And what heat gain there is in winter is a good thing for my basement.

 

[hwy17]

This is the reason I put my equipment in my basement, everything is cool all year long, never hot, never cold, just the right temp. And what heat gain there is in winter is a good thing for my basement.

No basements here but I thought for a moment today about pulling air up from our crawl space to feed the inverter.

 

[LydMekk]

Same here, basement ^^. More or less the same passive temp all year round without any heating or cooling, 21c.

 

[hwy17]

93 outside now and 98 degrees at the air intake on the equipment.

Ventilation might carry it to 40c/104. But we've got to 45c/113f and it just wouldn't work then. So a window A/C will be needed for backup in a true heat wave. Could still stick with it, theoretically a ton of ventilation, keeping intake temp at 45C, would retain 5kW output power, but I"ve got a natural draft water heater in this room too and I'd be worried that massive air intake and exhaust could spoil it's draft.

 

[pvdude]

Mine is mounted on the West wall of a concrete block shed.
Setting Sun heats up the wall.
I put a shade outside to keep the wall cooler.
Insulated the doors, which the thermal camera identified as a heat source.
Put a large box fan blowing on the system from across the room
The best thing was to put in a "through the wall" 14,000 BTU, 240vac air conditioner,
powered by the inverters. I leave it on all Summer. Works.
Photo of heat before all the modifications:

 

[SilverbackMP]

I put a 9k Mitsubishi mini split in my power shed. It’s only 12x12 but I have have 3x Sunny Boys, 4x Sunny Islands, and it will be somewhat of server room too.

Also provides heat/freeze protection.

Foam and rock wool insulation.

 

[hwy17]

Mine is mounted on the West wall of a concrete block shed.

Same, west wall but T-111 and wood frame, it really bakes in the afternoon.

The best thing was to put in a "through the wall" 14,000 BTU, 240vac air conditioner,

Yup, I just measured and the window I want to use is too small for a window unit so I think I'm of to find the cheapest split that I can find.

 

[Lt.Dan]

I have an uninsulated garage (or atleast 3 uninsulated walls, because the wall meeting the house is insulated), with a 12k BTU Mini Split to cool my garage. Today is 106*F, and the garage is a cool 78*F. It's not uncommon to see 115*F days here in the summer.

I chose this because I work in the garage a lot, and it's a bonus to be able to work and not sweat to death. I also wanted to make sure the batteries and Inverter stay nice and cool and live a long happy life.

From my limited research, LiFePO4 Battery calendar aging can be accelerated very quickly from high temps.

 

[timselectric]

My system has its own room in the center of the house.
Because it's the happiest in the same environment that humans are.
I already have (but not installed yet) a dedicated AC unit that will be directed to each unit for winter. When we are heating the house.
Not married, so my system is all that I have to keep happy.

 

[hwy17]

From my limited research, LiFePO4 Battery calendar aging can be accelerated very quickly from high temps.

Luckily my batteries do ok. With all their thermal mass and very low internal heat generation they stay probably 70ish.

 

[JRH]

93 outside now and 98 degrees at the air intake on the equipment.

Ventilation might carry it to 40c/104. But we've got to 45c/113f and it just wouldn't work then. So a window A/C will be needed for backup in a true heat wave. Could still stick with it, theoretically a ton of ventilation, keeping intake temp at 45C, would retain 5kW output power, but I"ve got a natural draft water heater in this room too and I'd be worried that massive air intake and exhaust could spoil it's draft.

I do that ..it works great in my set up…… I only run it when it’s hot enough to start affecting output..July / august.. +/-…… you can see it happening if you sit and watch the outputs…vs the temp…
And then only during the few hours of the day its hot where I’m at…

It’s a Midea 5000 btu ..draws about 450 watts when compressor runs…that’s about 25% of the time when it’s on… ……stays about 68 - 70 inside the equipment area…...Cost about 160 bucks at Walmart last summer.

When it cools off outside I revert back to ambient air and fans…morning and all night is no problem with just fans…usually 1:00 pm to about 6:00 pm in my area can get upward in temp.

Many may disagree, but it works for me…but then I don’t live in a really hot area…

J.

 

[Dooug]

Im just debating how to proceed with temperature control in my mexico place during the offseason.

Current battery storage is a large garage, lead acid and they sure get warm even in may while charging.

Debating leaving the system live all summer and running a small portable AC unit during daylight ours of ac out#2 in the multiplus. Have batteries in there own conditioned space inside the garage. Garage space is to large to air condition. Probably build a small battery box in the corner or maybe use a steel toolbox for them (firesafe!) and run the portable AC hose into it.

Will talk to other locals in the area when i get back down about how they manage it.

 

[Lt.Dan]

Luckily my batteries do ok. With all their thermal mass and very low internal heat generation they stay probably 70ish.

You would be amazed. I rarely saw my batteries within 10*F of ambient. I'm guessing because of self heating.

If it was 80* outside, the batteries were roughly 90-95*. Even worse when it was 110*F ambient.

 

[hwy17]

You would be amazed. I rarely saw my batteries within 10*F of ambient. I'm guessing because of self heating.

If it was 80* outside, the batteries were roughly 90-95*. Even worse when it was 110*F ambient.

I've got a sensor on a battery terminal and in the air in the battery case I'll check.

 

[Lt.Dan]

I've got a sensor on a battery terminal and in the air in the battery case I'll check.

Very nice to have! I should add I was just reading cell temp based on the temp probes from the BMS.

 

[greasemonkoid]

Glad I came across this thread, I'm about to put together a system that will provide power to shipping containers, and probably a well pump in the future. The components are enroute, but I've had to back up and think about this. So it looks like I'll need to build an insulated room inside the container housing the equipment, probably to have a small window AC in the wall. Just wondering, how many square feet should a dedicated equipment room be? Or is it realistic to think enough cfm of fresh air could do the job? It never gets over 100* here.

 

[hwy17]

Glad I came across this thread, I'm about to put together a system that will provide power to shipping containers, and probably a well pump in the future. The components are enroute, but I've had to back up and think about this. So it looks like I'll need to build an insulated room inside the container housing the equipment, probably to have a small window AC in the wall. Just wondering, how many square feet should a dedicated equipment room be? Does it need to have ballast mass to help regulate the temp or is that overkill?

I would do 1/3 or 1/2 of a twenty foot container if you're thinking like <100kWh battery and <20kW inverter.

Ballast mass won't change the overall thermodynamics, but if you're interested in it I would look at outsulating the container instead. Otherwise just inside box and the batteries will give some mass.

 

[SilverbackMP]

I would do 1/3 or 1/2 of a twenty foot container if you're thinking like <100kWh battery and <20kW inverter.

Ballast mass won't change the overall thermodynamics, but if you're interested in it I would look at outsulating the container instead. Otherwise just inside box and the batteries will give some mass.

I’d almost consider a full 20 ft container. I’m out of room in a 12x12. Granted there’s a man door and one wall is garage door (but a shipping container would still have an end wall door). I also have my server/switches stuff in there but it’s just two wall mount short depth racks with the smallest Husky adjustable height workbench (the kind that crank up and down) underneath them. And my Sunny Boys take up more room than SCCs. And my MidNite Solar Battery Combiner box takes up more room than a regular bus bar. And I have another small box that has MidNite Solar Lightning Arrestors for the incoming lines from the panels.

 

[hwy17]

Very nice to have! I should add I was just reading cell temp based on the temp probes from the BMS.

Yeah turns out it's higher than I thought. 30/31c 86/88f for battery and ambient inside battery case. I'm not necessarily uncomfortable with that, not counting on more than 5 years out of these cells, but it is higher than I guessed.

 

[Luk88]

This is the reason I put my equipment in my basement, everything is cool all year long, never hot, never cold, just the right temp. And what heat gain there is in winter is a good thing for my basement.

How big is your basement?

I have a small 2.2x4.5m cellar (not under a house) and I decided to install my inverters in the stairwell to provide fresh air cooling (there is a pvc curtain between the stairwell and the cellar to prevent condensation of hot air on cold walls). I decided it this way, because I thought the inverters will heat up that small cellar very quickly and I'll have to add fresh air cooling anyway so I may as well preserve that cold for the batteries.

I'm still building my system so I can't say what temps will be like. It is an insulated building and there will be a 100mm extraction fan(inlet through an existing gap under the door). Outside temps can get up to 35C / 95F so I hope inside will not exceed it.

 

[hwy17]

It looks like F45 is the Schneider error for caps over 105c that actually causes a temperature shutdown, and so far I have not found any reports online of anyone having encountered it.

There's a big delta between 40-50c ambient and 90c caps that could still allow for a considerable amount of cooling.

I'm thinking now this derating chart from the manual might actually be quite conservative. It's more like a guarantee, should not ever be getting an F45 within these bounds but there may be a lot of leeway outside of them too, just don't go complain to Schneider if it doesn't work.

So maybe I will stay the course with fresh air cooling and see what happens.

 

[ThaiTaffy]

So I live in east Thailand ambient temps this spring have been hitting 44°c/111°f on my shaded balcony I only fitted my larger system a few weeks ago and it's currently monsoon season so it's a lot cooler but summer will be a interesting test.
I'm automating large floor fans to try keep the inverter cool when the temps rise and I thought long and hard about the battery before purchasing and went with flooded hoping it was less likely to go boom but the online marketplaces here are filled with home made lithium batteries neatly constructed in chipboard boxes.

I have a feeling as the prices of solar drops here and the price of utilities goes up mixed with the lack of knowledge there will be a dreadful amount of solar induced house fires in the coming years.

 

[ThaiTaffy]

first one that popped up