Keeping the heat out.

[thedoc46]

I live in SW Florida. Which basically means my garage gets hot for a good 45weeks of the yr. Even today, where the temps only hit 78 with low humidity, tonight its a little too warm in my garage.

Making matters worse, My garage doors are south facing, so the sun beats on them during the day.

I need to figure out ways to reduce the temps in there, so i can work more comfortably, without it costing the earth, and not making it look ugly in the process. Just spent a tiny fortune on making the floor nice and adding lots of new cabinetry.

I know i can insulate my garage doors (its a 3 car garage) But will it really help? or just ever so slightly help ? Guess i'm looking for people who live in hot climates as i do, and who wanted to drop temps rather than keep the heat in. If you have actually gone thru this and have some real world experience on if it helped or not. I appreciate that during the summer a lot of the heat comes from the roof. I could throw some insulation up there, as the garage sits below of a non-insulated storage attic area of the home. I don't want to spend a fortune and turn it into a living area, and do a full AC setup.. Just want to make it a little more agreeable and not have to spray myself with insecticide and forced to leave the doors open in the even just to get a break from the heat.

Here's a pic of the garage doors.

 

[Zeke]

We don't do miracles here.

 

[dadsEH]

Big *** ceiling fans

 

[NUTTSGT]

Insulate the doors with some rigid foil faced insulation. Insulate the walls and ceiling. If that's not enough, get yourself a small window A/C unit to run while you're out there.

 

[Richard Cranium]

Yes insulate you doors, and install ceiling fans also. The more air you move the cooler it will seem.

 

[brownbagg]

i heard that radian tin foil barrier works good on sun heat

 

[crewchief888]

i lived in orlando for 15 years,

i learned how to sweat
i used a box fan when i was out there.

insulating the doors, and attic space will help...

 

[klassenl]

Insulation is the cheapest and most effective thing to do. Around here it gets hot in the day but it cools off at night. The insulation keeps the cool in and the heat out......at least for a few hours

 

[theoldwizard1]

insulating the doors, and attic space will help...

You need as MUCH INSULATION ON THE DOOR AND IN THE CEILING AS YOU CAN POSSIBLY FIT ! >R40 in the ceiling.

Then add a high efficiency (>30 SEER) mini-split A/C.

 

[Voi]

My garage doors are south facing...

I know i can insulate my garage doors but will it really help? or just ever so slightly help ? Guess i'm looking for people who live in hot climates as i do, and who wanted to drop temps rather than keep the heat in.

I live at 4000' elevation in South Dakota and have foil faced polyiso in my door channels. I had issues with it falling out of one panel a couple of summers ago and the amount of heat that radiated through the panel was very noticeable when you walked by in the morning.

My garage doors face north-east and get a little bit of morning sun and it was still noticeable.

South facing doors in Florida need insulation. I think you'll be surprised.

 

[admranger]

My experience with a well insulated garage is that when you drive that hot car in there, you have a nice oven and no way for the heat to escape... However, insulating the door will help with radiant heat transfer through the south facing doors. I'd do that for sure (I have west facing garage doors and the summer vegas sun is brutal on them...).

Put in some vertical ventilation if you can to create a chimney effect (drawing in cool air at the floor level, and exhausting the hot air through the ceiling area of the garage.

In an ideal world, a mini-split system is the way to go, but unfortunately for me, my electrical panel is maxed out and upping it to a 400 amp panel is cost prohibitive (I need to pull new main lines from the transformer to start...ugh).

 

[rayra]

insulate the doors, it makes a difference.
insulate the walls with as much as can fit. If necessary shim the wall studs to upsize the thickness of the wall and fill it with fiberglass.


Shade the exterior walls, south and west, any way you can. Consider a trellis and climbing or fast growing greenery on the west wall outside of the garage. Keep the sun off the walls and doors in the first place.

 

[JonnyMac]

In australia there are some distinct house design features which work in hot climates. Generally speaking insulation isnt a great solution because once the insulation has warmed up throughout the day it retains the heat through the evenings and the walls let out the heat when the heat drops off in the evening. The most efficient designs have light density characteristics combined with air flows and shade is a huge help.
If it were me in your position i would put some roof venting to allow all that hot rising air to escape and combine it with some fans. If that fails then AC is the only other option..

 

[thedoc46]

Perhaps i should of mentioned this in my OP. The four walls of my garage are as follows.

The front (south facing) is concrete with two garage doors. This is what i could insulate.

The north wall which has the entrance to the house is already insulated. Behind the drywall. As its to the house, and the entrance door is a heavy fireproof insulated type.

The East & West are concrete block, which there's nothing i could really do with. Besides i live in a deed restricted gated community, so i couldn't do anything with the exterior walls to try and deflect. But my understanding is that concrete block is not a bad thing to have anyway in keeping the heat out.

The ceiling, that's just plaster board on rafters, with a large attic storage space above. Its where i store all my large items, such as hurricane shutters, boxes, suitcases and so on. I like it being storage, so to insulate it would be a big job, as in having to put insulation in there and then covering it with plyboard so i can continue to use it as storage without breaking out into a rash, everytime i go up there (which happens to me with your typical fiberglass insulation)

I guess i could just start on the doors see what the difference is, and then perhaps move onto the ceiling.

I'm not apposed to putting in a minisplit, just don't think the wife would appreciate the cost.

I am concerned that i could be making matters worse in insulating the heat 'in' by insulating also, so keen to have a better understanding on what type of insulation i should be going with. For the garage doors at least.. For the ceiling, i'd use what the other part of the house uses, and that's rolls of paper covered fiberglass AFAIK

 

[zcar751]

It doesn't mater if it's hot or cold, trying to control and environment requires insulation and a device to raise or lower the temperature. I work in a concrete block office and the exterior offices that get the afternoon sun will get 10 to 15 degrees warmer than the rest of the building in the afternoon on sunny days. Concrete blocks are great heat sinks. They warm up with the sun light and radiate the stored heat long after the sun goes down. You will need to insulate the walls and attic space as well, and combine it with a method of removing heat. A mini split or window A/C unit will work but they will have a higher cost to run and with out insulation the expense will be higher. I think Admranger and JonnyMac hit the nail on the head for a cost efficient way of dealing with the heat by using ceiling ventilation. You need to pull the hot air out of the garage with some type of roof vent. Ceiling fans circulate the air but with out bringing cooler air into the space it will continue to warm up as long as the sun is shinning.
In my metal shop I couldn't go out and work in the summer until I put in a ventilation fan and vent to pull out the hot air. On a 75 degree day it would get to over 95 degrees when the sun was shinning. With the vent fan it was still 10 to 15 degrees hotter by late afternoon. Once I spray foamed the inside of the roof I didn't have any problems and the vent fan wouldn't start running until it was over 85 degrees outside were in the past it would kick on at 70 if the sun was out.

 

[mygarageone]

I did a test with the foam foil face samwhiched stuff . I built a tin box , lined it with the foil insulation . Put in direct sun light .
Took the inside temp and the out side temp after an hr in 90 degree outdoor temps , the inside of the box was 20 degrees cooler. So yes it makes a Hugh differance.

 

[tstaude]

Find a commercial sized window unit, it will treat you well.
Another option is a dehumidifier, I have done this in 10k sf areas and it really does help cut the heat back.

 

[Nowater]

My insulated garage door faces east and warms to the touch by midday, but is cooler than outside surfaces. Worry about sealing air changes first, then insulate, and lastly add an air conditioner. I put in a larger unit from Lowes and cool to about 76 degrees in the summer. Do not siphon air from your home system and dump it into the garage.

I tried a portable air conditioner and returned it as I thought it was useless.

Radiant energy striking your block wall will take 8 to 12 hours to move through the block and radiate to the inside. Is there any chance of planting some vegetation along the exterior wall?

Many Florida homes have only a 3/4" foam insulation panel for the interior walls. Build a false wall inside the garage.

 

[theoldwizard1]

The front (south facing) is concrete with two garage doors. This is what i could insulate.

Foil faced, polyisocyanurate has the HIGHEST R-vale per inch of any common insulation (>7, polystrene is about 4). Closed cell spray foam is about 6.5 (check the specs). 2" minimum, 4" would be better. Polyiso is not cheap, but just to do the door should not be too bad. It should stick with typical construction adhesive.

The ceiling, that's just plaster board on rafters, with a large attic storage space above. Its where i store all my large items, such as hurricane shutters, boxes, suitcases and so on. I like it being storage, so to insulate it would be a big job, as in having to put insulation in there and then covering it with plyboard so i can continue to use it as storage without breaking out into a rash, everytime i go up there (which happens to me with your typical fiberglass insulation)

If you want to keep it for storage, it is going to cost you. Again, foil faced,
polyisocyanurate or closed cell spray foam, applied directly to the underside of the roof decking. 4" minimum, 8" better.


As I said before, always double check the insulation product R-value specification. If you are contracting the work out, get the R-vale of the product being used IN WRITING, preferably from the manufacturer.


You are likely STILL going to need a mini-split if you want to work in there COMFORTABLY during the day in the middle of the summer ! From what I know of AZ, nighttime temps don't get that cool, so big fans are NOT going to pull in much "cool" night air.

 

[CNGsaves]

If you're not willing to INSULATE . . then you just have to bear it !!

Really, a house that nice in FL should never have had a "builder's grade" flimsy garage door. A typical cheap steel garage door facing south is just a heat sink to crank up temperatures in FL garage.

Also, PLANT TREES . . . . . shade that portion of house if possible.

 

[sublimate]

Paint your doors white (match the trim) as well. That will reduce the heat they absorb.

 

[pmiranda]

The name of the game is insulated area. A garage door is big, and if uninsulated, will transmit alot of heat. Those block walls are big and uninsulated, so once they warm up in the morning they will be sending heat into your garage until well into the night. Insulate them, too. If you don't want to insulate the ceiling, at least have vents that will pull cool air from the soffits on the shady side of the house and push out hot air out the top... a continuous ridge vent is nice, and a powered fan would be even better. But that ceiling will still be transmitting warmth unless you insulate it. Rigid or expanding foam insulation is not itchy. Don't forget to insulate the attic access panel.

Like everyone said, shade trees will help alot, keeping those block walls from getting hot and providing a cool area for the soffit vents to draw from.

All of that will also help lower the cooling bill for the main house.

Finally, I think there are some pretty reasonably-priced DIY mini-splits you could put in quickly. Make up some BS about how much money you'll save by doing more car maintenance yourself instead of paying the dealer.

 

[Ben7203]

Same issues here. Everything is insulated. 2 box fans and a pedestal fan make evenings tolerable. You're dealing with hotter summers and higher humidity, figure you need a mini split system or a window
unit

 

[DC73]

I guess i could just start on the doors see what the difference is, and then perhaps move onto the ceiling.

You'll get the most improvement from insulating the ceiling. Blow in cellulose would be a good option. Low cost and you can do it yourself. It's dusty but you won't have a problem with it giving you a rash.

DC

 

[cruzinZ]

I used 2" styrofoam insulation on my garage door. In the summers it would get up to 110 in the summers. The garage would routinely get up to 135-140 in the hot summers. After the insulation on the doors it would keep the temps down to 85 on those hot days if we kept the hot cars outside.

 

[theoldwizard1]

Another option is a dehumidifier ...

AZ has very low humidity, that is why you can use a "swamp cooler".

Also, PLANT TREES . . . . . shade that portion of house if possible.

Trees, in AZ ? Ha ha ha ! Shade trees need soil and water.

 

[UpNorther]

Best thing to do is insulate door and like someone else said, blow some cellulose in the ceiling is cheap. Even if its just 6" blown in, then board it over for your hurricane window storage, etc..

 

[941designs]

I'm also in SW Florida. I bought an industrial pedestal fan, pushes an insane amount of CFM. I also have two overhead curling fans.

As far as the bugs, my propane handheld bug fogger is a great way to knock em down every week or so!

Good luck, I'm guessing you are new to Florida, I'm born and raised here!

 

[thedoc46]

Liking the idea of cellulose and just doing the garage doors. Worried about the vented soffits though getting covered in cellulose, also how much of a job it would be to board the rafters, given the opening to that attic space isn't all that large. Don't have to do all of it. Just partially boarding will work !

 

[DC73]

Liking the idea of cellulose and just doing the garage doors. Worried about the vented soffits though getting covered in cellulose, also how much of a job it would be to board the rafters, given the opening to that attic space isn't all that large. Don't have to do all of it. Just partially boarding will work !

They make cheap vent baffles you can staple to the underside of the roof to prevent blown insulation from blocking the soffit vents. You can get them at Home Depot or Lowe's.

DC

 

[heywood22rbr]

I used to do rentals down towards New Orleans, and I ALWAYS painted the doors white. It definitely cools the doors down. My own house here has 3 sets of double exterior doors and three regular doors, and all of them are bright white!

 

[rattle_snake]

#1 is a ventilation fan. Best is a thru wall, but if wall is block then you may have get creative. Put the fan on a timer and run it at night, 3-5am. You will need an intake vent as well, it can go in the garage door itself.

If you park a hot car in it every day, insulation isn't going to help other than the overhead doors that face the sun

 

[thedoc46]

I will not be allowed to paint the doors white, just because every home in the community has a matching mocha brown garage door, so its the part of the HOA rules... I may not even be allowed to run a minsplit out of the garage walls, depending if it's not properly hidden from public eye. Just the way it goes living in a gated community..

I'll keep my eye out for a ceiling fan. But i have to be careful there too. As i have the rails for both garage doors, and then the lights among other things such as my 24ft ladder hanging down...

Here's my garage, and yes, two cars will be pulling into there every night.

 

[1991Syclone]

Living in Florida with most new construction has it's drawbacks compared to other parts of the country

1) At least 1 or more walls in the garage will be concrete block. You typically get furring strips and tack them to the block and use rigid foam insulation between the strips and then drywall over it.
2) Judging by the drawing of the house, and the mention of an HOA leads me to believe that you won't get away with a window shaker hanging out the side of your garage window.
3) Insulate. Pull all the **** out of the attic and lay fiberglass rolls between the studs or get blown in insulation and then put the plywood flooring back in.
4) Insulate the garage door with those kits from Lowes or Home Depot that attach between the door and the bracing. For one of the posters that complained about builder grade garage doors, I would venture that the ones installed in Florida will withstand a better wind load than in other parts of the country.
5) It's not uncommon to have the air handler installed in the garage up against the ceiling. You might be able to get away with cutting a vent hole in the outlet leading up into the attic, but you don't want to overtax the system trying to cool a garage.
6) Someone on here in the Orlando area installed a heat pump water heater in their garage: http://energy.gov/energysaver/heat-pump-water-heaters It basically pulls heat from the air to assist in heating the water. It might help, it might not, but I'm guessing that yours is installed somewhere in your garage. Beware that these are not cheap. I think the member got a credit from the water company or something.

Based on the drawing, it looks like your garage doors are dark in color which isn't going to help with a south facing door. If the house is already built and you have an HOA, I'm not sure you'll be able to change the color without asking for approval. You'd probably have to paint the house too.



EDIT - made the post before you put up the photo. Doesn't look like a water heater or A/C in the garage, so those ideas are probably out.

 

[Nowater]

From 1991Syclone:

"5) It's not uncommon to have the air handler installed in the garage up against the ceiling. You might be able to get away with cutting a vent hole in the outlet leading up into the attic, but you don't want to overtax the system trying to cool a garage."


Tapping into the house AC unit is dangerous and does not meet code. I have seen intelligent people do it, but that does not make it safe.

 

[1991Syclone]

From 1991Syclone:

"5) It's not uncommon to have the air handler installed in the garage up against the ceiling. You might be able to get away with cutting a vent hole in the outlet leading up into the attic, but you don't want to overtax the system trying to cool a garage."


Tapping into the house AC unit is dangerous and does not meet code. I have seen intelligent people do it, but that does not make it safe.

I can guarantee you that there's a lot of **** that people on this forum have done that does not meet code. It's up to the individual to decide if it's worth it or not.

 

[theoldwizard1]

IMHO 6" of blown/poured cellulose in the ceiling is not going to cut it ! Yes, it will help, but that is only about R12. You need more like R30 or greater in the ceiling/roof.

If you do go with the limited amount of insulation in the ceiling YOU ABSOLUTELY MUST HAVE A POWERED EXHAUST FAN IN THE ATTIC ! You want the attic temp as close to the outside ambient temp as possible.

 

[markharleypainter]

Beleive it or not...insulation and keeping all.doors and windows closed. ..works for me.brings it down about 8 degrees on a 80 degree day?

 

[theoldwizard1]

Beleive it or not...insulation and keeping all.doors and windows closed. ..works for me.brings it down about 8 degrees on a 80 degree day?

AZ - regularly over 100F !

 

[jives]

Go to BuildingScience.com and GreenBuilding.com and see what they have to say, or Green Building Advisor:

http://www.greenbuildingadvisor.com/blogs/dept/building-science

Figure out how to use the sun:
http://www.builditsolar.com

Or, move out of the HOA as fast as you can so you can buy/build with common sense, rather than HOA rules.