Hot Top Floor Options
All – Like many, the top floor of our Brooklyn rowhouse is very hot. I’ve been reading the posts and am interested in the following options: (1) Installing a fan in our roof hatch to vent the top floor. Although it wouldn’t meet fire or building code, it seems like an easy place to install…
All – Like many, the top floor of our Brooklyn rowhouse is very hot. I’ve been reading the posts and am interested in the following options:
(1) Installing a fan in our roof hatch to vent the top floor. Although it wouldn’t meet fire or building code, it seems like an easy place to install one, if you could figure out a construction that made it weather-proof. Has anyone explored this? Or can folks recommend a contractor with expertise?
(2) The idea of wind-powered fans to vent the space between the roof and the top floor ceiling sounds smart. Does anyone know of a contractor who installs them? Many thanks!
Parkslopemom,
I have doubled the size of the roof this year, so I am watering the newly planted sedums about weekly until they get established. The ones I planted last year, could do fine without water, except if it is really hot and sunny and does not rain for a week, I go and water them. But generally, that’s been the case on only one occasion this year. It’s a lot of fun, since I get to see them blooming as well and they have colorful flowers.
In the winter, the plants die down and reappear in the spring. They’re perennials.
Heatherie, check out the below link where they have a diagram comparing black tar roofs, cool / reflective roofs and green roofs. We had the reflective coating on ours. But, even then in the summer, the roof would heat and the asphalt / tar would get soft from the heat. Now with the sedum trays on the roof, the asphalt underneath is cool and stays solid. http://www.ssbx.org/greenroofs.html
My green roof was really quite reasonable, since I did it myself. I added about 150 sq ft this year and it cost me $280/-. I already had the sedums, which last year I bought for $150, so I did not have to spend on those, since I just used cuttings.
I will post pics soon.
In the meantime, if anyone wants more info, contact me at: yash7 at aol dot com.
Thanks all for the many helpful suggestions. Our roof is already silver and insulated. I’ll definitely explore the timed window fans and solar shade ideas. Does anyone have a model of window fan that they like? Do they come with louvers on the outside to make them weather-proof? And has anyone actually tried the wind-powered roof fans to vent the space between roof and top floor ceiling? Many thanks!
I’ll preface this by saying, I’m all for green roofs (and am looking to install one on my place). From what I understand, though, you’ll only see significant A/C savings if you have a roof-mounted A/C system, since the air being drawn into the unit is cooler than with a non-green roof. Otherwise a reflective roof is about the same, interior temperature-wise.
Green roofs offer very little insulation, and are a lot more expensive to retrofit than applying a reflective surface (in this case). The cost difference is much lower for new construction. There are many other benefits to installing a green roof though, including great water retention and personal enjoyment.
Have you noticed a difference in temperature, ohiise?
ohiise: Thanks for the pictures and links. Now that you have had your green rood for a while – how is it working? Do you ever have to water it or does occasional rain water do the trick? What about in winter?
Second the window exhaust fan. Leave it on a timer to come on in the early evening. During the day, close all windows and drapes. Open them at night.
Also second painting the roof with the silver paint.
However, this is a prime situation for a green roof. Cools your roof, decreases A/C costs, lengthens the life of your roof, traps stormwater and is pretty.
And an extensive roof (less than 3″ deep) will not burden your roof too much even when wet. The Sundance channel had a show on a brownstone owner in the Bronx who installed one.
And here are some links to our ownhumble project:
http://reclaimedhome.com/?p=415
http://bstoner.wpengine.com/forum/archives/2007/10/green_roof.php
Is your roof black? You definitely don’t want the black paint or tar on the roof. It will heat up the top floor big time.
Whatever you do about vents or fans or whatever, if your roof is black you need to paint the roof silver.
Another thing – don’t let the sunlight in the top floor during the most sunny, hot hours of the day. Blocking out sunlight from your interior can lower temps inside several degrees. Use blackout shades, or lined drapes, or well-made wood blinds you can close completely or set at an angle so direct sunlight does not enter.
1- A large exhaust fan mounted in a top floor window would do much the same thing, with no installation cost.
2- I think any roofer could install vents