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Does anyone have any experience,or know of any products such as a ridge vent for the angled ridges of a hip roof? I have a 2000 square foot hip roof house that only has about 6 feet of horizontal ridge but about 100 lineal feet of eave vents. Currenlty, I have an attic fan that operates from June to Sept in Houston and the temp still exceeds 135 in the attic during the day. It has a thermostat, but the fan still only lasts about 1.5 years. Any suggestions?
Garry
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Hi Garry,
By your information, I assume that your exhaust fan is burning out because it's overworking due to a lack of air intake from the various vents in your attic.
I'm also assuming that you have the hip roof configuation on all four sides, leaving little or no ridge area on the top, nothing on the four sides and 100 feet on the eaves.
You may have to add roof surface vents to help balance out the available air for the capacity of your fan. They would have to be stratigically located at the upper corners to maximize the air flow.
I would strongly recommend that you contact a local roofing contractor to help with the layout.
Gabe
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Joseph Fusco View Image
*Gary. Another reason for the fan burn-out may be because it is trying to do something it can't do: flush radiant heat out of the attic. The main heat transfer mechanism in an attic is radiant heat. Radiant heat cannot be flushed out of an attic. Installing ridge vents on hips is rarely done. It is "ïffy": it may or may not work, and must be done only on low pitched roofs. A ridge vent witout an external badffle is a must.The external baffle would channelwater into the attic. Roof vents are either with a fixed cap or a rotating cap--the so-called turbine vent. When either of these vents are located in a positive pressure area air can and does enter the vent.The net free venting area of these vents is quite small,40 to 80 square inches, and make balancing them with the soffit vents nearly impossible. There is also the aesthetic issue of a roof loaded with roof vents. Furthermore, little of the air entering the soffits vents reaches the roof vents. The attic is not vented with these vents becuse only a very small area in the immediate area of the vent is washed.As many of you regulars know I have cited many times the research that shows that attic fans may lower the attic temperature but they have little or no effect on the house's total air conditioning load.Researchers found (see for example Ira Block's paper, "Attic Ventilation and Energy Conservation" published in the ASHRAE Journal February 1980--order from ASHRAE at 800-5-ASHRAE)that adding insulation was the most cost effective way to handle the problem. Finally, what insulation? Low density Fiberglass is transparent to radiation: it allows the radiation to pass right through it. Cellulose is less transparent: it absorbs the radiation and "keeps"it very close to the surface of the insulation.I hope this allows you to more inteligently decide a course of action.Joe fusco says " maybe"to FredL's suggestion. Note, however, that the Florida Solar Energy Center is now recommendiñg for the Southern USA no attic venting, and its replacement with insulation, and of course, light colored roofs. I hope this allows you to more intelligently decide a course of action. GeneL.
*Ridge Master ridge vent makes a product called Hip Master. It is a great way to vent the hip roofs like yours. I have used it on a few buildings(houses, churches and banks) Not a bad product, but I did seal down the Hip Master with a rubber sealant(the Hip Master has a maze of baffles to keep out the rain/snow but I tent to go the extra mile whenever possible) Some of these projects are over 10 years old and I have not had any call backs on any of them.
*Have you considered using standard roof vents? Install a few on the backside of your roof. I would think that ridge vents on the hips would look odd.Pete
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Does anyone have any experience,or know of any products such as a ridge vent for the angled ridges of a hip roof? I have a 2000 square foot hip roof house that only has about 6 feet of horizontal ridge but about 100 lineal feet of eave vents. Currenlty, I have an attic fan that operates from June to Sept in Houston and the temp still exceeds 135 in the attic during the day. It has a thermostat, but the fan still only lasts about 1.5 years. Any suggestions?
Garry