Loft Conversion with Inverter in loft

JimLad

Hi Guys!

Having my loft converted to add a couple of bedrooms so the solar inverter is now in one of the rooms. They have built a cupboard around it with a door.

I was wondering about ventilation of the inverter? It sometimes has a fan that runs. Is it going to die or something now its in a confined space?

I could put a little vent in the door to help?

Crowmann

It needs to be moved - they require free flowing air around them. You will kill it if you place in a cupboard / it will shut down due to heat.

in a similar vain my iBoost shut down the other week due to excessive heat - did not know they could. Kinda pleased as placing electronics handling high wattage (it serves a hot water cylinder and then a storage heater) in a warm airing cupboard has always struck me as risky.

pinnks

I guess the question is, is the inverter in a cupboard in the room, of in a boxed off part of the loft? The latter might get a bit hot but the latter is probably not too bad as neither room nor cupboard will get that hot (hopefully) without the inverter and they don't push out that much heat, well my SMAs don't.

I would suck it and see I think.

Crowmann

Thats the joy of a forum always folk talking - some nonsense however.

If your inverter has fins on the rear (it almost certainly does) then it requires the free flow of air behind from below and typically at least 300mm of headroom to a ceiling - if fitted.


The fan is their to give capacity in high temp periods when free flow is insufficient - high summer typically.

Do not box it in - it simply is not designed to function in that environment.

Take a look at the instructions - it will give install requirements.

pinnks

Don't disagree with the airflow point but it also depends on the size of the "cupboard". Inverter plus a few cm is clearly not good but one the size of a wardrobe? As Crowmann says, the installation instructions will set out the requirements but the point I was trying to make is that as long a that cupboard is unlikely to get as hot as the old attic space then you shouldn't have an issue.

The_Green_Hornet

It will all depend on what model of inverter you have and what minimum clearances the installation manual says you must observe.

Martyn1981

JimLad wrote: »

Hi Guys!

Having my loft converted to add a couple of bedrooms so the solar inverter is now in one of the rooms. They have built a cupboard around it with a door.

I was wondering about ventilation of the inverter? It sometimes has a fan that runs. Is it going to die or something now its in a confined space?

I could put a little vent in the door to help?

At the very least I think you need to add low and high vents for air circulation.

Have a look a t the inverter specs, also the efficiency - my older and smaller SMA's used to heat my downstairs toilet with a combined efficiency of about 95%, but the Solaredge at close to 99% efficiency produces almost 80% less heat.

I've also got a Solaredge inverter in my loft, but they have one of the best designed and enormous heatsinks I've ever seen.

But here's the key question, in converting the loft I'm going to assume that it will now have excellent insulation? In that case it won't heat up with direct solar gain on tiles/slates, but instead will follow the ambient temp. Also, of course, PV panels help with this blocking most of the direct sunshine. My loft with insulation, lots of PV and a Velux open an inch or two follows ambient temps, so no longer an oven up there.

That said, and taking aesthetics into account, can you create a big opening at the bottom, and perhaps no 'lid' to the cupboard, so it acts like a chimney and draws cooler air in as the inverter warms up the air around it.

Oh, and one last question, how low/high is the inverter? My loft model is close to the ground. Obviously lofts with smaller rooms and sloping rooves have a much smaller volume than 'normal' rooms, so they get hotter easier and less high space means the heat heads lower faster ....... if that makes sense?

JimLad

Martyn1981 wrote: »

At the very least I think you need to add low and high vents for air circulation.

Have a look a t the inverter specs, also the efficiency - my older and smaller SMA's used to heat my downstairs toilet with a combined efficiency of about 95%, but the Solaredge at close to 99% efficiency produces almost 80% less heat.

I've also got a Solaredge inverter in my loft, but they have one of the best designed and enormous heatsinks I've ever seen.

But here's the key question, in converting the loft I'm going to assume that it will now have excellent insulation? In that case it won't heat up with direct solar gain on tiles/slates, but instead will follow the ambient temp. Also, of course, PV panels help with this blocking most of the direct sunshine. My loft with insulation, lots of PV and a Velux open an inch or two follows ambient temps, so no longer an oven up there.

That said, and taking aesthetics into account, can you create a big opening at the bottom, and perhaps no 'lid' to the cupboard, so it acts like a chimney and draws cooler air in as the inverter warms up the air around it.

Oh, and one last question, how low/high is the inverter? My loft model is close to the ground. Obviously lofts with smaller rooms and sloping rooves have a much smaller volume than 'normal' rooms, so they get hotter easier and less high space means the heat heads lower faster ....... if that makes sense?

Ok so they have built a full height cupboard with a regular door on. Theyt have put a postbox size vent in the bottom of the door. You can see it here....

JimLad

pinnks wrote: »

Don't disagree with the airflow point but it also depends on the size of the "cupboard". Inverter plus a few cm is clearly not good but one the size of a wardrobe? As Crowmann says, the installation instructions will set out the requirements but the point I was trying to make is that as long a that cupboard is unlikely to get as hot as the old attic space then you shouldn't have an issue.

It is a little bigger than the size of a regular door...see my previous post with a picture

Martyn1981

JimLad wrote: »

Ok so they have built a full height cupboard with a regular door on. Theyt have put a postbox size vent in the bottom of the door. You can see it here....

I don't know?

It's a nice big cupboard, but at the very least I think you need a high level vent for air circulation, and I'd be nervous that 'stuff' will be put in the cupboard. If you buy a nice looking flat vent in a colour that's suitable, then you could just cut out a section or drill some large holes (with a cutter), then screw the vent over the top. It'll look nice and be a very simple job.

But, if the room doesn't get silly hot anymore and the inverter install description says it's ok, then maybe. Perhaps leave the door open during summer months? But gotta have a high level vent IMO.

Edit - My logic is that the inverter will be fine in a warm (not hot) loft, but not so good in a cupboard unless it makes good use of the room's volume.

JimLad

I found this in the manual:

There should be a 200 mm clearance on both sides of the inverter for the cool air vents.

When installing the inverter in a switch panel cabinet (or similar closed environment), it is
necessary to make sure that the hot air that develops will be discharged by forced ventilation.

https://www.manualslib.com/manual/1254657/Fronius-Ig-Tl-3-0.html?page=26#manual

200mm clearance is no problem, but the hot air discharge might be a problem....

Anyone have any suggestions how i can remedy? Would vents in the top and bottom of the door be sufficient?