Solar Panels and Attic Heat

[alantrav]

Perhaps a stupid question but Internet searching has not found an answer for me...

I am trying to convince my wife that solar panels on the roof are useful despite the fact, they are not sexy to look at. (Matter of opinion)

The question is if installing Solar Panels will help to keep our house cooler. The front of our house is south facing. and has little shade. Our master bedroom is on the second story and gets dang hot during the day. My question lies in the thought, solar panels are absorbing the energy which are currently just pouring into our attic, and consequently into the upstairs, front of the house bedrooms.

Hopefully this question doesn't prove me to be an idiot. Trying my best to convince wife that solar on our roof is a good thing.

Alan

[Nando]

Alan:

Any surface separated from the roof with some thickness will give solar flux insulation, though it depends on the total area of the roof and the total area of the solar panels.

Since you have an attic, why don't you use a thermal radian barrier ( aluminum material ) to reflect the infrared ray back to the roof, it gives an improvement equivalent to about 8 to 10 R improvement and about 8 % energy usage savings .

visit : http://www.radiantbarrier.com/ and Google thermal radiant barrier for more places.

Also: What about water misting the roof, it is a technique that just barely wets the surface without any run of, then sometime later mists again, this can reduce the attic temperature down to around 100 F.

I did my first roof spraying about 4 decades ago.

Nando

[terramir]

ehh well one thing is for sure the solar panels will get hot in summer, but this is just my educated guess, while solar panels don't really absorbe that much heat I would say the spacing below it will be air that doesn't move all that well (depending on installation) just by convection mostly, hence the sun blocking by the solar panels, combined with the insulating qualities of air that is pretty much moving slowly should give you some insulation from the summer sun.

For the bedroom I must say you should consider windows that insulate I.e. keep the airconditioning in and the heat in in winter double pane glass helps, also curtains help a bit too in the summer, to block out the warming rays.

But this is just my .02

so dun shoot me if I'm wrong

terramir

[terramir]

also yeah what he says is true however your goal is solar panels so yeah do the solar panels first :p because that's what you wanna do and then do the insulation as well. As for misting you wanna avoid that if the solar panels are not 100% sealed lol

terramir

[jimjjnn]

Try a Thermostatic controlled attic fan. Lowered my electric bill 30% in the summer as my A/C ran 1/2 as much.

[mukunthko]

There's the law of conservation of energy, instead of u'r rooftop and hence u'r house absorbing the energy in the form of heat from the sun, the solar panel would send the energy into u'r batteries instead as electrical energy.

So u'r house would be cooler Both in terms of temperature as well as the looks ( I personally think solar panels r cool)

[Turbulent]

When I put solar panels on my roof it reduced heat build up in my ceiling space (attic)by a few degrees and if I touched the roof on a warm day 43c (109.4f) under the panels the roof was warm to touch but in the exposed area (like an idiot) I touched it and burnt my hand.

I do belive it must do something because my A/C is not strugling on these warm days like it used to so the answer should be yes but it depends on how much of the roof area is covered by the panels and gap between panels.

My roof area covered is just over 80% 10 meters by 20 meters (33 feet by 66 feet) approx with a 100mm gap, that is hell of a lot of panels but so is my electricity demand.

[jspears05]

I have a stupid question myself. I have recently purchased a home and it has 4 4x8 solar panels attached to the roof. They are connected in 2 sections and they are attached at about a 60 degree angle. I have no idea what they are for. I have also had some individuals stop by and offer to remove them for me if they can have them. Should I allow this or will they benefit me in some way? Please help-- BTW what are they worth??/

[jimjjnn]

you need to give more info.

Are the panels water heating or PV panels?

[Gordy]

jspears05,

Have a look at them. Electric panels will only have a set of wires coming out of them. Hot water panels will have pipes going to them and should have a small wire also for a temp sensor. 4x8's are probable hot water.

IMHO they are worth allot more to you, than to someone that hopes you are dumb enough to let them have them for there removal. I wish I could get lucky and find a sucker to give me a system for removal ;-)

Give them a good up close look, and write down any info. you can find on them. Then post it here so we can get a better idea of what you got. Also try to follow the pipes or wires to see where they go and what there hooked to and let us know.

There are allot of those old systems out there that were installed by flyby nighters, that broke down and the owners could not find anyone to fix them. So they just let them sit. A friend found a hot water set up the only thing wrong with it was the temp. differential unit to turn the pump on. He got it free by asking the owners, who said it was junk and only worked for about 8 month of the 20 years it was up.

If yours is broken, you can get plenty of help here to fix it. And save a bunch of money in the long run :-)

Good luck,

Gordy

[elvin1949]

Nando

 Misting works well for me.

Been diong it for 15 yr's now.

later

Elvin

[elvin1949]

 You don't have to mist to get the same effect.

Place a Soaker hose at the peak of the roof,with

a timer set to just keep the roof damp under

the solar panel's.

 The air flow up the roof under the panel's

will evaporate the water cooling the roof,

and the back or the panel's.

 It might raise the efficency of the panel's

while cooling the house.

 Just a thought.

later

Elvin

[la7qz]

Hi

It's a long time since I've lived in a house, but I have worked in the building trade...

I think this will make your roof and attic cooler in every way. And, for those really sunny hot days, instead of dumping excess energy into a dump resistor, install a relay and dump the energy into some fans to move air around that bedroom. The fans will come on exactly when they are most needed.

If your wife still won't let you have your panels, then you need a new wife.

Some months ago, the BBC World Service had series of programs on renewable energy. One of the products mentioned was new roofing products where the actual roof is the solar panel which can be installed by roofers with no RE experience and looks like an integral part of the roof. Right now, I'm fighting a very shaky WiFi connection just to be able to post this, but I'm sure there is more information on the BBC World Service website.

Regards,

Owen Morgan

Yacht Magic

Falmouth Harbour, Antigua

[la7qz]

Hi again

I managed to get a good enough connection for a Google and found this:

http://www.toolbase.org/TechInventory/techDetails.aspx?ContentDetailID=619

You think your wife might go for that? This product probably won't cool down your attic though.

Regards,

Owen Morgan

Yacht Magic

Falmouth Harbour, Antigua

[jspears05]

I have found out that they are actually 4x8 panels that are used for the hot water heater. The house is about 30 yrs old and I have no idea when they were originally installed. I do know that the house uses an electric water heater and I assume the panels are not "hooked" up to this. Any idea what they might be worth? I am looking to fix the house up and sell it. I would rather sell the panels and not worry with trying to get them working.

[Bruce S]

jspears05;

 The house will have a much higher selling value even IF those panels aren't in working condition.

The buzz around the realestate biz is that houses old or new with RE working or not will have a higher "persence of mind" to the buyer than one that doesn't. All depends on the perosn doing the selling .

FSBOers can point them out and what they are.

Realtors will for sure telling the perspective buyer what they are and how everyone is trying to do their part to help to enviroment.....

Even if you don't mess with them and try to get them working, you may not have to , just leave 'em, 1/2 the cost of units could be the installation costs.

Just a thought

Bruce S

[turboredcart]

i see ppl use a bamboo type of roll down shades for porches and such.  awnings can have same effeect.

i seeb a trelliis-lattice- "patio roof"- with assorted plants.   new materials-applications are being used to shield the sun.

i haad even stappled a screen to a 2nd floor window- the netting was a shade thing-

keep in mind uv rays can come thru ur clothing.

one job i had- teh magnicfication of the booth window was so bad- i resorted to a peice of cardboaard up. was the best i could do.

i used to go to a tanning booth- but since skin censer runs in family ---i stopped. yet- im often depressed- and like alot of light....

[tecker]

I think solar panels are very sexy and chick too.Shingles are not sexy

[tecker]

What I was going to add but got side tracked and this might be a good selling point to the lady of the house .The dead air space is the heating element and good ventilation will do the trick in most cases . Vent the highest point and put a big fan to cross ventilate . I installed two turbine vents ,also very sexy with ceiling fan motors adapted to the shaft . I used bicycle rear hubs the turbines can turn without the fan and the bikes brake is good in winter . Ceiling fan motors work well with 200 watt inverters low speed.