Solar Tube

[Travelover]

I'm anti sky lights of any kind...........

Can't argue with your logic - no skylights means no skylight leaks. I see it as kinda like owning a dog. You know it is going to die and break your heart, but you get a lot of joy from it in the meantime. YMMV

 

[SandburRanch]

I'm anti sky lights of any kind. Mostly because of all the long terms issues that I've seen from them leaking or the plastic deteriorating or the damage that is doen to the paper and shingles around them during instalation. The older the shingles and paper under the shingles, the more brittle they are, and the more likely you are to create problems down the road by disturbing them.

Your ceiling is the most important area for insultion. Creating a hole in your ceiling means there is no R value in that area. Kind of like putting a hole in a boat. It wont sink, but it's going to let water in. How much heat will go up and out through that skylight?

For the cost of the light, the price to install it and the loss of energy you lose because of it, why not install a 40 watt light bulb?

Eddie

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Exactly.

I've enjoyed our skylight that lights the stair well to the basement but I've found it doesn't work too well at night except if the moon is in the correct position, full and all the stars aligned just right.

If it was to be repeated, I'll just take the divorce and install a flourescent and leave it on 24/7.

After the first re-roof job it leaked and sure enough water found its way through elect. conduit to the basement light fixture and ceiling fan.

Never again, not in my normal lifetime.

 

[ultrarunner]

I'm anti sky lights of any kind. Mostly because of all the long terms issues that I've seen from them leaking or the plastic deteriorating or the damage that is doen to the paper and shingles around them during instalation. The older the shingles and paper under the shingles, the more brittle they are, and the more likely you are to create problems down the road by disturbing them.

Your ceiling is the most important area for insultion. Creating a hole in your ceiling means there is no R value in that area. Kind of like putting a hole in a boat. It wont sink, but it's going to let water in. How much heat will go up and out through that skylight?

For the cost of the light, the price to install it and the loss of energy you lose because of it, why not install a 40 watt light bulb?

Eddie

Seen a lot of Velux Skylights in Europe... can get very cold... they are insulated and appear to be very well built. Installation is critical and always better when done at the same time as the roof.

Knock on wood... have not had a problem yet...

Europeans are sun worshippers... anything to help pass the many long grey days of winter... Winter Gardens are found in almost every new home... kind of like an enclosed porch, all windows with skylights... I can attest to being almost too hot on a day below zero when the sun was out...

 

[EddieWalker]

How do they insulate the glass/plastic part? Double pane glass windows with gas between them give you less then an R5 value. Your ceiling should be R30 at a minimum and R-60 being much better. What is the R value of the sky light? and you can get an idea of how big of a hole you are putting in your ceiling and how much energy you are wasting to provide more heat or cold air in your home.

Ignore all the other gimmicks that they do with the tube and the happy feeling that the light gives you during the day. Look at the numbers and then decide if this is something that you need or will even notice once it's installed. I like the look of them in family rooms and kitchens. Don't understand them in bedrooms or other rooms of the house.

Eddie

 

[dave1949]

Hey Dave, bet you don't need a very long ladder to get on your roof >. I have an earth berm home also.

Actually don't need any ladder Especially in winter, I can step from the snow pile to the roof. I go across the back of the house with the tractor FEL and 3pt blower to get rid of what has slid off already and make room for the next batch.

Those berms are worth their weight in heating oil :laughing: but take some different strategies in snowy areas.

Dave.

 

[dave1949]

I'm anti sky lights of any kind. Mostly because of all the long terms issues that I've seen from them leaking or the plastic deteriorating or the damage that is doen to the paper and shingles around them during instalation. The older the shingles and paper under the shingles, the more brittle they are, and the more likely you are to create problems down the road by disturbing them.

Your ceiling is the most important area for insultion. Creating a hole in your ceiling means there is no R value in that area. Kind of like putting a hole in a boat. It wont sink, but it's going to let water in. How much heat will go up and out through that skylight?

For the cost of the light, the price to install it and the loss of energy you lose because of it, why not install a 40 watt light bulb?

Eddie

I had three Velux crank open skylights on our last house. Never had any trouble with them for 12 years. The light was good but I didn't get the chimney effect I was hoping for in summer. They were on a south facing roof and I think the heat on the roof surface cut down on the cooler interior air rising into the heated exterior air above them.

I understand adding anything that is optional like a solatube to a house is adding the possibility of some sort of trouble. We all make our choices and have our own ideas of what is important to us personally. I figured if I didn't like them or had problems, they are easy enough to remove. A patch on the roof would be the only visible clue that something was ever there.

As far as insulation values for a solatube, if it is sealed well at the ceiling and the dome, you have a column of dead air space. Dead air space is what makes insulation work. There will be some heating of the air in the column from the sunshine, but all that does is melt some snow on the flashing on the roof as far as I can tell.

There are plenty of things TBN'ers have put in their homes costing a lot more than a solatube that I wouldn't - because I just don't see the value, but a home is about personal choices. If people are happy, I'm happy for them.
Dave.

 

[hizoot]

I'm in the HVAC biz here in Texas. Eddie is right on. Especially here in the hot south. I've measured these velux solartubes and a couple of derivatives with a Fluke infrared heat gun, and found temps averaging 130-140 deg F at the interior surface. This corresponds to most attic temps down here in the summer.

 

[dave1949]

I'm in the HVAC biz here in Texas. Eddie is right on. Especially here in the hot south. I've measured these velux solartubes and a couple of derivatives with a Fluke infrared heat gun, and found temps averaging 130-140 deg F at the interior surface. This corresponds to most attic temps down here in the summer.

I just measured the surface temp of my solatube diffusers before the sun got on the roof domes: 55*F The adjacent ceiling surface is 66*F. The room air temp is 67*F. I didn't measure the attic air temp, but doubt it was much above 5*F overnight. It was -4*F all night from 10pm until sunrise. No heat was added to the room overnight. Basically, the room was 'coasting' on the retained heat in the floor slab.

I take two things away from this, some radiant cooling of the air column within the tube is occurring from the uninsulated portion of tube in the attic and the roof dome. And the dead air space in the tube, plus some radiant heating of the diffuser interior surface from room air, is preventing the air inside the solatube pipe from being equal to the attic and exterior air temperature.

I will measure the temp of the diffuser interior surface this afternoon, it's going to be a mostly sunny day with a high of 20*F.

There are on average only about 2 weeks per summer here when AC would be a nice thing. Most of that time, a ceiling fan is all that is needed to be comfortable. 90*F is a very hot day here and there are usually less than 6 of those days per year. Some 'so called' summers :laughing: have none at all.

It's important to recognize regional climate differences and how they affect choices for homes. Do I care if I have a 10" diameter circle that is worst case 11*F below the room temp? - No I don't. I also don't care if it is adding some heat in the summer. It is not enough difference to be an issue. 90% of my heat comes from the sun. Running ceiling fans adds very little to my electric bill over the summer season. Different climate, different construction, different costs, different ways of thinking about things.
Dave.

 

[dave1949]

Took more temp readings at 2pm today. Room air temp was 79*F. Solatube diffuser was 71*F and the adjacent ceiling temp was 76*F.
Dave.