Attic Ventilation in Hot Homes
Question: Can you tell me how best I can ventilate my home, which is modeled on the Cape Cod style with the upper level having a short knee? I got answers from three contractors all of which were different from each other. With the onset of summer, the second floor and the attics become oppressively hot. I intend to install new shingles. I think that this is the right time for making changes.
Answer: Even if your home was a Victorian, tri-level, colonial or whatever, I will have the same answer for you. The attic in any house that is traditionally built gets heated up with direct sunrays. I have found it difficult to breathe in attics during mid-summer. The attic resembles a blaze that within seconds my skin burst out in sweat. The temperature, I guess, should have been around 130F.
Countering infrared heat and high temperatures is indeed a challenge in Cape Cod style home. The roof rafters are steep and its bottom usually rest atop the walls of the first floor. A lesser livable space is created on the second floor as the roof rises to meet at the centre of your house. Knee walls or small vertical half walls meet beneath the rafters. The ceiling area of a good number of Cape Cod style homes have a ceiling area that is small and flat in the midst of the living area of the second floor. The underside of the roof rafters creates the remaining ceiling space.
A major problematic area is the slanted ceiling. Several Cape Cod roofs are bordered with 2 x 6s and on odd instances, 2 x 8s. Carpenters can use rough lumber of smaller dimensions because of the small vertical knee wall. Space for insulation and the free space required above the insulation are hardly there with the small lumber. It is necessary to have free air space above insulation. It is the channel through which cool air can flow through the attic space.
Hot attic air should be expelled continuously to keep your attic sufficiently cool so that this makes sure that the completed living space is cool. The air gets hot in the attic resembling the heating in a furnace. The noon temperature on a summer day with direct sunlight can heat up the roof surface to as much as 190F. This severe heat then passes on to the wood rafters and wood roof sheathing. The amount of heat radiated is large though it does not glow like a cooking element of an oven. The heat is collected by the air in the attic which then is transferred to the insulation which in turn gets hot and the heat is transferred straight to the completed ceiling. The transfer of heat is known as conductive heat transfer.
I prefer to rely on Mother Nature and would rather use wind power to expel hot air accumulated in the attic. Large quantity of hot air is pulled out from the attic spaces b turbine vents that are wind-powered. It hardly takes 30 minutes by your roofers to install these cheap devices. Installing them on the rear of a roof will also make it hardly visible when one looks from the front yard. Do not purchase turbine vents with internal braces. You should get one with external bracing instead.
Large volume of air is also moved by electric-powered attic ventilation fans or what is called as PAV fans. The problem with these fans is that they may cause great suction that they then draw air even from the interior of your home. In case you are operating air conditioning then the cool air can be drawn to your attic from the finished living space. Low-roof static pot vents or soffit ventilations required in abundance by both turbine vents and PAVs. This assists in the cooler air from the outside easily enters and replaces the hot air that is expelled in your attic.
I installed radiant barrier chips to increase the comfort at my home. The heat is reflected back to its origin by these thin plastic pieces that functions like mirrors and are highly reflective. In another sense, this works similarly like the aluminum foil that is used to cover a casserole dish. However, any radiant barrier that is of single layer would lose its potential to reflect heat if it is covered with dust. The chips offer this advantage as it does not create this kind of problem. On installation of chips, thousands of thee drift down against the insulation. You will find that there are six or seven layers of radiant barrier lying one on top of the other. Even if the top layer gets dirty, it does not matter as the layer below acts as though they are new.
The house will not become necessarily cooler with more of the insulation. When the sun sets, these can increase the heat load. The heat transfer is slowed by the insulation as it is designed for this function. If your home is warm and you do not want the cold attic to receive the heat, then this is the thing for you. The insulation should be as cool as is possible, especially the ones that reach up and contacts with the ceilings. The heat finds its way back to the attic if the insulation is hot.
You need to move large volumes of air through the attic space for keeping the insulation cool. The outside temperature of 90-98F is definitely much cooler than 140-160F. the extreme temperatures if your attic can be thwarted by your air conditioner in your home. If you are able to make sure that the attic temperature is lowered by even 15-20F you will not only be cooler but also saving money.
Roof Turbine Vents
Question: There are two spinning turbine vents in my home. A number of people have suggested the idea of stuffing insulation into these vents during winter to make sure that warm air does not get drawn out of the attic place. Do you think this advice worthy? Are the turbine vents actually efficient? The roofs of my neighbor do not have them. Should I get rid of these turbine vents?
Answer: Those vents are actually superb devices for ventilation. Leave them alone. A long time ago I installed the very same vents in my second home. These have turned out to be hardy ones that Mother Nature operates. These vents are there on my home even now drawing air every time when the slightest of breeze blows, from the attic space.
The turbine vent as also the traditional metal pot vents and the commonly liked ridge and soffit ventilation systems are passive ventilation systems. Unlike these, the active ventilation could be electric powered such as the powered roof ventilator or the whole house fan. The advantages with the passive vents are that invariably these are silent when it operates and do not need electricity. They work for free. Read more
Crawl Space Vents
There are numerous people who simply do not know the use of crawl space vents. I was puzzled with these small vents when years ago I was involved in installing them in rooms that were built new. I used to wonder at the science behind the vent that mostly prevented air from entering the crawl spaces. I could hardly feel any draft of air coming through the vent when I was in the crawl spaces even on windy days.
The logic with which crawl space ventilation operates is not so difficult to decipher. Place a clear plastic piece on the dry ground in your yard. Place some boards on the edges of the plastic to keep it on the ground so that air does not get under the plastic sheet. You can see the results immediately if it is a sunny day.
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Ceiling Fan - Buying Tips
You can purchase a ceiling fan for as little as $40, is looking for a high quality fan these can cost up to several hundred dollars each. Of course the more you pay the better quality you get and high-quality fans have several traits that you will not find any fan for under $100.
Some things you need to look for when purchasing a fan make sure that the fan is well designed and is made from high-grade materials. Make sure the warranty is good possibly up to 10 years longer warranty, check the motor and fans come with several speeds.
Fan are rates by the amount of air that they can, although these are measured in cubic feet a minute to not really relevant question is no set the standard. Something else you 
should look out for is to make sure that the motor is strong and silent type.
From the technical side motor should have sealed bearings that require no lubrication, this type of more should last for 10 years and up. The movement of air is a key factors to the pitch length also the number blades and how far they are from the ceiling.
Some of the best motors made by American companies like Emerson and General Electric, but of course you can get high quality motors that come from China and Taiwan for example.
Dryer Vent
I discovered a small mouse the other day in my side yard. The dryer vents are also located there. After chasing the mouse, I had almost cornered him close to the dryer vent adjacent to a few recycling boxes. When I edged the box aside, I could see that he had used the vented dryer lint to make a small bed. The mouse leapt up and darted into the dryer vent, which was not operating then.
The vent had angled covers for directing the air down. Until then I had simply ignored how the vent works. But then now I wanted to make sure that the mouse did not set up house there. Hurriedly I scrambled back into the house and got the dryer going for a minute. My desire was to scare the mouse away. But then I did not see any sign of him outside. I reckoned that he got away. Or may be still holed up there, but would sneak out when he is hungry. This incident took place a couple of days ago.
But today I was overwhelmed with a terrible stink when I entered the laundry room. I just knew it. The worst has happened. I got the dryer out after prying open the flexible metal duct located between the wall and the dryer.
I took it outside cautiously and I saw the dead mouse at the back of the dryer sitting in the 90-degree angle fitting attached to it. That was barely an inch away from the inside of the dryer.
There is a big flap in our exhaust vent under the external angled cover. It was open about half an inch with years of lint accumulated there. The mouse must have jumped up and put the nose into this half inch gap and squeezed himself inside. But then it had squeezed in too far inside. There was a U pattern upside down inside the flexible ductwork. He must have crawled up the incline to the top of the inverted U from the hole in the wall after which he must have fallen down the other side. He must have tried to climb back to the top of the inverted U from where the exhaust exits the dryer at the floor level, but failed. Bad luck!
After cleaning it thoroughly, I reinstalled the duct back to its old self. Since then I am careful and I check the exhaust vent when I take the trash out every week. I made modification to the path of the flexible duct to a U pattern to dissuade future intrusions.
