A Case for Solar Tubes / Sun Tunnels

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tweake

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#3357544 26-Mar-2025 16:50

Handle9:

No it shows that fixating on a single design element is flawed. There is more to the design of a building than a single metric.

sort of. its the one metric they leave out of the design because there is no legal requirement to design for it.

Handle9

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#3357547 26-Mar-2025 16:51

tweake:

RunningMan:

Whilst your priority is clearly solar gain when designing a building, please realise and respect that not everyone shares the same priorities, and they may value the additional light, view, or feelings of openness as opposed to a solar gain figure. It doesn't in any way mean those buildings are poorly designed, as they reflect the requirements of that person. It simply means the priorities are different to yours.

<sigh> try telling that to all the people currently complaining about overheating homes. its been in the news multiple times. its a well known problem and even branz has publicly said its a "house design problem". the houses are simply poorly designed and thats from the professionals, not just my personal opinion.

What you don't see anywhere is "it's a too many windows problem." It's not one thing that causes overheating or cold houses.

tweake

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#3357561 26-Mar-2025 17:32

Handle9:

What you don't see anywhere is "it's a too many windows problem." It's not one thing that causes overheating or cold houses.

kinda right there, its not just one thing. but windows is a major part of it. the simple problem is to much solar gain combined with lack of shading, because of nz culture of wanting lots of windows with no shading over them, modernistic design and architects have no way to push back against that. it doesn't help that the industry promotes it.

what's really changed is peoples expectations to have a comfortable house.

RunningMan

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#3357562 26-Mar-2025 17:42

tweake:<sigh> try telling that to all the people currently complaining about overheating homes. its been in the news multiple times. its a well known problem and even branz has publicly said its a "house design problem". the houses are simply poorly designed and thats from the professionals, not just my personal opinion.

None of those people are complaining in this thread, nor is that relevant to the OP, who clearly does not have a home that is overheating in such a way. Yep, there is a particular style of (predominantly) 3 storey terraced housing that appears poorly designed and overheats, with one element of the problem being window area. Yep, we get you're motivated by that issue, but it's simply irrelevant for the OP, who from the info provided seems to have a single storey home without enough windows.

tweake

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#3357564 26-Mar-2025 17:54

RunningMan:

None of those people are complaining in this thread, nor is that relevant to the OP, who clearly does not have a home that is overheating in such a way. Yep, there is a particular style of (predominantly) 3 storey terraced housing that appears poorly designed and overheats, with one element of the problem being window area. Yep, we get you're motivated by that issue, but it's simply irrelevant for the OP, who from the info provided seems to have a single storey home without enough windows.

sorry this has drifted off to a side discussion. it applies to single story homes as well, not just the 3 story one featured in the news. plenty of them also have the same issues for the same reasons.

for the op, its just cost and risk compared to perceived benefit. one other thing to look at is if solar tube lens is flush with the ceiling. mates one was curved sticking out (to spread the light). that might look kind a weird on a big flat ceiling.

tweake

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#3357587 26-Mar-2025 19:06

@FineWine just a thought. why not get one of the battery powered dome lights and stick it on the ceiling to see what it looks like, the sort of light coverage, whats the best placement etc. a cheap way to try it out.

eracode

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#3358059 27-Mar-2025 21:51

tweake:

@FineWine just a thought. why not get one of the battery powered dome lights and stick it on the ceiling to see what it looks like, the sort of light coverage, whats the best placement etc. a cheap way to try it out.

A new low here? Let’s go one better - forget solar tubes and think solar system.

I was out of this thread but couldn’t resist this.

Sometimes I just sit and think. Other times I just sit.

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tweake

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#3358267 28-Mar-2025 17:41

eracode:

tweake:

@FineWine just a thought. why not get one of the battery powered dome lights and stick it on the ceiling to see what it looks like, the sort of light coverage, whats the best placement etc. a cheap way to try it out.

A new low here? Let’s go one better - forget solar tubes and think solar system.

I was out of this thread but couldn’t resist this.

🤣 thats very funny 😃

FineWine

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Nurse (R)

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#3358591 29-Mar-2025 15:43

OK. Thanks all of you for your input.

The other quote came through after an on site scope. = $2,517.50 for one tube.

This was a research exercise, as the topic title suggested, with the thought that if it came in around the $1500 mark approx, then we would seriously think about. Yea, dream on. The second quote would have won, though.

However, we are not made of money and we do have solar panels. So, as some of you above have said, cheaper to run LEDs, which we already have. But they are not as good in all aspects, as natural light.

When our house is in neutral mode, it consumes 0.2-0.3 kWh. When we turn on one (dining room) or four (lounge area) or all 5, it does not make a dent in that reading.

So, thanks everybody. It was/is an interesting discussion. 
 
I don't know what's happened to the formatting - sorry

Whilst the difficult we can do immediately, the impossible takes a bit longer. However, miracles you will have to wait for.

FineWine

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Nurse (R)

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#3363159 12-Apr-2025 13:13

So just to round this topic out. We went and bought a ceiling LED dome light, all from Lighting Plus Tauranga.

JANUS.2 35W CCT IP54 WHITE 40CM LED CEILING LIGHT @ $107.40 was $179.00

Wattage: 35W
Integrated LED (non-replaceable)
Luminous Flux: 3420lm
Colour Temperature: CCT 3000K, 4200K or 6500K
Dimmable
CRI > Ra 80
Average Life: 20,000hrs
Classification: Class II (Double Insulated)
IP rating: IP54 (Dust protected. Prevents ingress of dust sufficient to cause harm. Protected against water splashing at any angle.)
Beam Angle: 110°
1-Year Warranty

We set the colour temperature at, 4200k

Also installed was a trailing edge dimmer:

MEDM DIMMER SWITCH KIT @ $71.40 was $119.00

2-400w load
Rotational dimmer control
Dims to off with most LED lights
Two wire design - no neutral connection required
Compatible with PDL, HPM and Clipsal switch plates
3-year warranty

A HPM Excel 4 Gang Grid and Plate Gloss White from Mitre10 for $8.68

Lighting Plus recommended an electrician they use for their shop, and he came and installed it all plus the Electrical Safety Certificate all for $138.00

So all up Total $325.48

And boy, it is just like daylight. Who needs a Solar Tube for $2½ grand. Dimmer full on for the morning paper and crossword and dimmed down for intimate dinner at night. Plus the added benefit of light spill over into the lounge area and the electrical usage still doesn't budge off 0.2-0.3 kWh.

Whilst the difficult we can do immediately, the impossible takes a bit longer. However, miracles you will have to wait for.

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