Heat from the solar inverter.

I am sure the inverter its self has overheat-protection etc. But the flat under the house is getting rather warm, we have no opening windows, only ventilation is the bathroom extractor, and normally not a problem, built into the hillside as it is, it neither gets super hot nor cold.

The space would have been a garage, before turned into a granny flat, so opening patio doors and turning on a fan which blows the air around in a circle and out the kitchen door, would quickly cool the rooms if outside air was cool. But it isn't, the outside air is hot, not helped by the slabs laid outside so we have a flat area for a BBQ, not a problem at the moment as the flat is rarely used.

However, plan is, when we get old, we will move to flat, and daughter will live in main house, so at some time in the future, we will want it cooler. Moving the inverter outside would help, but it's a lot of work, so a vent seems a better idea. But would want some automated control.

So looking for ideas. Inverter in the corner so we have a composite panel next to it. Behind the chair. Google Earth shows or rather does not show, how the flat is protected from the sun to some extent by trees, so we have time, is that the answer, a tree close to the flat so shaded more?

Looking for ideas, before we have to live in the flat.

How warm does the room get?

Our inverter is in the hall cupboard, and leaving the door ajar has capped the temperature at 29 degrees, whilst the hall room stat has registered 28 degrees

So flat is the warmest area where I have thermometers. There are also thermostats, hall TRV 23°C wall thermostat 26°C living room TRVs 27°C and 25.1°C wall thermostat 27.5°C the dinning room TRV 21°C the rest are not readable online, so don't know the temperature, but flat is in spite of the door being left open the warmest place in the house, at 29.2°C.

However before solar, it was likely coolest group of rooms in the house. It would have been cooler than the dinning room, in the flats kitchen the inverter near the door, and the thermostat is at the back of the kitchen, mainly there so I can see when cool enough to start brewing again, which is why I know before solar, the flat would remain at 18°C or below so I could start a brew, if within first 5 days the brew goes above 20°C it can result in a bitter after-taste, so brewing stops this time of the year.

Had it not been for the brewing, I would be unaware of temperatures on previous years. The solar installers wanted to fit the inverter and batteries in the loft, thank goodness I didn't let them do that.

I know the flat ceiling has loads of insulation so no too much heat raises to living room, but some must of course.

ericmark said:

I am sure the inverter its self has overheat-protection etc. But the flat under the house is getting rather warm, we have no opening windows, only ventilation is the bathroom extractor, and normally not a problem, built into the hillside as it is, it neither gets super hot nor cold.

The space would have been a garage, before turned into a granny flat, so opening patio doors and turning on a fan which blows the air around in a circle and out the kitchen door, would quickly cool the rooms if outside air was cool. But it isn't, the outside air is hot, not helped by the slabs laid outside so we have a flat area for a BBQ, not a problem at the moment as the flat is rarely used.

However, plan is, when we get old, we will move to flat, and daughter will live in main house, so at some time in the future, we will want it cooler. Moving the inverter outside would help, but it's a lot of work, so a vent seems a better idea. But would want some automated control.

So looking for ideas. Inverter in the corner View attachment 418221 so we have a composite panel next to it. Behind the chair. Google Earth shows or rather does not show, View attachment 418222 how the flat is protected fnf online from the sun to some extent by trees, so we have time, is that the answer, a tree close to the flat so shaded more?

Looking for ideas, before we have to live in the flat.

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If the inverter is what's changed, I'd look at removing that heat directly rather than trying to cool the whole flat. A thermostatically controlled vent or small extractor near the inverter would likely be much more effective and cheaper than relying on outside air or additional shading.

trucrio61 said:

If the inverter is what's changed, I'd look at removing that heat directly rather than trying to cool the whole flat. A thermostatically controlled vent or small extractor near the inverter would likely be much more effective and cheaper than relying on outside air or additional shading.

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I am looking at this, the problem is if I make a cover and fit fans etc. If this fails the inverter may overheat. So looking at a chimney of some sorts so it does not need a fan.

ericmark said:

... So flat is the warmest area where I have thermometers. .... but flat is in spite of the door being left open the warmest place in the house, at 29.2°C. ... However before solar, it was likely coolest group of rooms in the house. .... Had it not been for the brewing, I would be unaware of temperatures on previous years. The solar installers wanted to fit the inverter and batteries in the loft ....

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I'm a little confused. Are you talking about the situation in 'recent' times (i.e. the last few weeks)?

You appear to be making comparisons with before and after you had solar panels (hence an inverter) installed and seemingly 'blaming' that for the temps you are observing. However, during recent weeks most of us have seen unprecedently high temps in some rooms in their homes, without the appearance solar/inverters being part of the equation. Furthermore, in anticipation of what your response may be, I have to say that in my particular house, some of the rooms that have been getting extremely hot are not ones would have expected to be the hottest, and I don't really know the reason for that!

I was looking at which is the coolest room in the house. Not the actual temperature, and I had selected the flat as that was always the coolest room, so selected for beer brewing, had I not wanted to brew beer, I would not have been noting what temperature the flat was.

As it stands it does not really matter the flat being hot, but as I get older, the plan was that my daughter would move into the house, and either my wife or I who ever lives longer, will live in the flat, so want it ready for use when required.

ericmark said:

I was looking at which is the coolest room in the house. Not the actual temperature, and I had selected the flat as that was always the coolest room, so selected for beer brewing, had I not wanted to brew beer, I would not have been noting what temperature the flat was.

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Yes, but as I was trying to explain, and although I don't understand the reason, we have experienced similar due seemingly to the almost unprecedented climate we've been 'enjoying' - soime of the parts of the house which normally would have been the coolest have become the warmest, and vice versa. Very odd.

In your case, I imagine that we may well have had 'abnormal amounts of sun', hence abnormal amounts of PV-generated electricity for the inverter to deal with.

I really think you need to wait until the climate (hopefully!) returns to something closer to 'normal' and see what the situation is then!

ericmark said:

As it stands it does not really matter the flat being hot, but as I get older, the plan was that my daughter would move into the house, and either my wife or I who ever lives longer, will live in the flat, ...

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For a start, as with incandescent lighting, there is only a potential issue in summer, (when heat generated by the lights or inverter is both unwelcome and a 'wast of electricity' (hence, usually, money). In Winter that 'unintended heat' merely helps to heat the house, mean that less 'other energy' is needed (and, of course, there will also be less PV-generated electricity, hence less 'inverter heating' in the Winter).

I wonder how much PV-generated electricity you are getting with the present amount of sunshine, and how 'inefficient' your inverter can be? I don't think that 'a small handful of kW of heat (if your inverter were that inefficient) would not have much impact on the temp of the totality of the average house, would it?

ericmark said:

so want it ready for use when required.

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... as above, if you wait for the return of a more usual climate, you might find that it already is 'ready' (but I hope that both of you are around for a good time longer, before the need arises )!

The inverter is 5 kW, the panels 6 kW, it was assumed it would be rare to have maximum output from panels, so 5 kW is enough for the inverter, and that does seem correct.

39 kWh on 7th July 2026 is the best so far, I expected more near the solus, but the panels are on a south-west roof. The graph on the 7th does not show a flat top, so it seems the inverter was big enough. Peak was after true midday around 13:35 real time, where I am, again likely due to panels not being due south. By 7:30 pm solar was near enough gone, there was a little until 10:30 pm, but such a small amount, could be counted as zero.

But I can open both doors in the flat, and turn on a fan, but with a patio outside, the air outside gets hot, so prediction today and so to cool whole flat with a fan, does not really help as the day goes on, well same for most rooms in the house, so want a sensor which, if room warmer than outside, and over say 22°C want fan to run. As it stands no ready built unit to do that. OK you and me could program a PLC, but in the main we are looking at these I have the Inkbird ITC-1000 which I use for brewing, and it seems most of the units sold either for brewing or keeping reptiles. There are fans which both pull air in and blow air out, but they are designed not to get rid of heat in the house.