ProHouston Posted July 29, 2009 Share Posted July 29, 2009 Ok, I'm considering a few options to make my house more energy friendly, but I can't decide what is best. Can y'all provide some insight into the benefits of:1) Radiant Barrier - At $1400, is it worth it?2) Ridge vents - At $1000, is it worth it?3) Solar fans - At $550 each (I need 2), is it worth it?Thanks ahead of time! Link to comment Share on other sites More sharing options...
BryanS Posted July 29, 2009 Share Posted July 29, 2009 1) No.2) Yes.3) No.Good ventilation, R-38 blown-in (you can insulate your entire attic for a little more than one of those solar fans), a programmable thermostat, and an eletric plan tied to natural gas (.10 or less per kwH).You will see a significant reduction in your bill.EDIT: You can put ridge vents on yourself for much less than $1000. I did. Link to comment Share on other sites More sharing options...
rigas Posted July 29, 2009 Share Posted July 29, 2009 i say YES YES AND NO!anything you can do to keep the heat reflected/ away from the house is ALWAYS good. ridgevent alone doesn absolutely NOTHING. if you dont have soffit vents and/or gable vents then what is the point? the hot air escaping cant escape without the cooler air to replace it. as for radiant barrier will actually keep that air cooler in the 1st place. Link to comment Share on other sites More sharing options...
ijaxon Posted July 29, 2009 Share Posted July 29, 2009 if this is a new home or reroof?, i'd say all three are great options, but the price is a different story. The radiant barrier decking installed on new homes or reroofs works very well. I'd recommend at the very least ridge vents, and solar fans work well and tie in the whole "attic ventilation system" But for it to truly work you should also have perforrated soffits or vents.if this is an existing home and the roof will stay intact, i'd say no to the spray on radiant barrier. not a fan of it at all. but yes to rv's and sf's but to be green there are many things that factor in. the attic ventilation is just a start. Link to comment Share on other sites More sharing options...
TJones Posted July 29, 2009 Share Posted July 29, 2009 If it is "spray on" radiant barrier, then NO. I have a new radiant barrier product coming out very soon, I will get you the name for it today, it DOES work but is a little more pricey than $1400 but I believe they give you (in writing) a guarantee to save a minimum of 25% on your electric bill. Ridge vents work excellent as long as you have the soffet vents as was explained earlier. You have to calculate the cost with how much you are gonna save and how soon will you recoup the money spent. Link to comment Share on other sites More sharing options...
ProHouston Posted July 29, 2009 Author Share Posted July 29, 2009 Wow, this is great advice. I knew I could count on HAIF. My home is 8 years old and does have great Soffit Vents already in place. So what is your advice for Ridge Vents vs. Solar Fans? Link to comment Share on other sites More sharing options...
musicman Posted July 29, 2009 Share Posted July 29, 2009 Wow, this is great advice. I knew I could count on HAIF. My home is 8 years old and does have great Soffit Vents already in place. So what is your advice for Ridge Vents vs. Solar Fans?what is the design of the roof? does the ridge span the entire length (or a good portion)? If not, the ridge vents may not provide adequate airflow. Link to comment Share on other sites More sharing options...
ProHouston Posted July 29, 2009 Author Share Posted July 29, 2009 what is the design of the roof? does the ridge span the entire length (or a good portion)? If not, the ridge vents may not provide adequate airflow.I've got at least 2, maybe 3, sections of 15-20 ridge spans. The ridge doesn't span the entire length though. Link to comment Share on other sites More sharing options...
keepitlow Posted July 29, 2009 Share Posted July 29, 2009 I've got at least 2, maybe 3, sections of 15-20 ridge spans. The ridge doesn't span the entire length though.Assuming you are re-roofing the house and are installing new roof decking with a radiant barrier, then yes.Ridge vents will help with a very moderate amount of heat relief as they are primarily there (along with intake from soffit vents) for reliving humidity from the attic. That humidity is developed primarly in the winter time when it is warm in the house and cool in the attic. Do not listen to anyone that says ridge vents are there for reducing heat in the attic. They are not primarily for that purpose. They will help some but not what you wish for in helping to relived heat in the attic. A radiant barrier will help keep the attic cooler. What you are trying to acheive is having the temperature in your attic be as close to the outside temperature.Solar powered attic vents should not be used if you are installing ridge vents. Also, if you have old gable end vents, then make sure the are closed off when ridge vents are installed and provide for an adequate amount of soffit vents to balance the intake and exhaust. Link to comment Share on other sites More sharing options...
BryanS Posted July 29, 2009 Share Posted July 29, 2009 Assuming you are re-roofing the house and are installing new roof decking with a radiant barrier, then yes.Ridge vents will help with a very moderate amount of heat relief as they are primarily there (along with intake from soffit vents) for reliving humidity from the attic. That humidity is developed primarly in the winter time when it is warm in the house and cool in the attic. Do not listen to anyone that says ridge vents are there for reducing heat in the attic. They are not primarily for that purpose. They will help some but not what you wish for in helping to relived heat in the attic. A radiant barrier will help keep the attic cooler. What you are trying to acheive is having the temperature in your attic be as close to the outside temperature.Solar powered attic vents should not be used if you are installing ridge vents. Also, if you have old gable end vents, then make sure the are closed off when ridge vents are installed and provide for an adequate amount of soffit vents to balance the intake and exhaust.I'd really like to see some hard data to backup your claims, because this is probably the worst advice I've seen for a long, long time.First, ridge rents absolutely offer heat relief in the attic. Hot, humid heat relief, in the summer. We don't care about winter around here. You make it seem like we are adding ridge vents to solve some winter heating problem. I know not one person who's done that to solve a winter problem. It's all about HOT, summer time heat. Heat rises straight to the peak line of your roof, and is vented at the roofline. Only very large gable vents are better... here is some discussion on Bob Villa's web site:As an example, take a 1500 sf house 25' x 60' with a 6:12 gable roof 60' long. The attic volume is about 4700 cubic feet.Assume the house to be fitted with three turbine vents on the roof and 30 soffit vents (4' centers both eaves). The soffit vents let in the cooler air and the turbine vents let out the heated air. A 12" base dia. turbine vent is 0.78 sf x 3 each = 2.34 sf. The soffit vents are usually 4"x10" (or smaller) stamped vents with about 25% free area which, for 30 vents, translates to 2.00 sf. The smaller of the two areas is the controlling opening size. Thus there are 2 sf of area to ventilate 4,700 cubic feet of attic. If the heated air is moving at the velocity of 2 feet per second (generous) the system will remove 240 cfm of air. With the attic volume of 4,700 cf divided by 240 cfm, it will take 19.58 minutes for one air change (3 air changes per hour). That is not going to cool the attic very well.Ridge vents advertise openings of 12 to 20 square inches per linear foot. Converting, 20 si = 0.139 sf x 60' =8.33 sf for the entire ridge. That is nearly four times the area of the 3 turbine vents! Remember, equally large (or larger) soffit vents areas must be provided to supply the air for the ridge vents.Traditional gable vents are 10' to 12' long with about 60% free area which calculates out to 21.65 sf per vent. With one vent at each end of the roof you have 43.3 sf of vent area. That is FIVE times greater than the ridge vent. NOW we are moving some air and heat!Given enough linear ridge line and matching volume uptake at the soffits, ridge vents beat out turbines, other passive roof venting. My gable vents are only 8' in length. Some houses have even smaller gable vents. Adding heat relief at the peak of your roof line (ridge vents) only helps the situation. I hear that you should close off gable vents after installing ridge vents, but I rarely have seen that done.Spray-on radiant barrier is a farce. Adding a radiant barrier, that is not already adhered to the backside of roof decking, it too much of a hassle, too little return. I've been in attics that have radiant barrier. Still hotter than hell up there. Thank God, in those cases, there was a mountain of insulation up there. Not to mention they really needed some ridge vents, to get more of the heat out. Link to comment Share on other sites More sharing options...
musicman Posted July 29, 2009 Share Posted July 29, 2009 I've got at least 2, maybe 3, sections of 15-20 ridge spans. The ridge doesn't span the entire length though.sounds like you have quite a bit of length but without seeing the roof it is hard to tell whether it is adequate. if you do ultimately go with a ridge vents make sure and purchase one with a design that maximizes airflow. it's not all about hot air rising, the better ones are designed to create a low pressure area (when air blows) which creates a stronger suction which improves the flow. Link to comment Share on other sites More sharing options...
keepitlow Posted July 29, 2009 Share Posted July 29, 2009 As I said, the PRIMARY purpose of ridge vents (coupled with adequate soffit vents) is to relieve the attic of humidity / moisture caused by the difference in temperatures between the inside of the house and the exterior. Ridge vents where made to combat the harmful effects of attic humidity / moisture that decreases the life of roof decking, roof underlayments (mainly non-breathable asphalt felt paper) and shingles. The SECONDARY purpose is heat relief in the summer.If you don't belive me, ask a manufacuter of ridge vents (Lomanco or GAF to name two). Or you could just google "Why Are Ridgevents Important" and you will see that ridge vents (exhaust) coupled with proper soffit vents (intake) will cause the Venturi effect and actually cause cooler, dryer outside air to be pulled into an attic. When the cooler, dryer air enters the attic, the moist air already present will be pulled through the ridge vents and removed in a continous cycle in the summer and the winter. Regarding hard data, this has been studied and put into use for years now. If you want to reduce heat in the attic during the summer months, then a radiant barrier is necessary (or you could use a new solar reflective shingle, ie. CertainTeed Solars of GAF Timberline Cool Colors). Link to comment Share on other sites More sharing options...
TJones Posted July 30, 2009 Share Posted July 30, 2009 Here is the product and the website for it. It is called E-Shield. There is also Eagleshield, which is pretty much the same stuff. I have seen the product in action first-hand, and I believe it actually does what it claims.http://www.eshield.net/science.htmlhttp://www.eagleshield.com/Products-Services.htm Link to comment Share on other sites More sharing options...
Fringe Posted July 30, 2009 Share Posted July 30, 2009 Ridge vents should not cost you a $1000. I had some installed a few years ago for around $250. They do help but don't expect any big change in your electrical bill. Link to comment Share on other sites More sharing options...
BryanS Posted July 30, 2009 Share Posted July 30, 2009 As I said, the PRIMARY purpose of ridge vents (coupled with adequate soffit vents) is to relieve the attic of humidity / moisture caused by the difference in temperatures between the inside of the house and the exterior. Ridge vents where made to combat the harmful effects of attic humidity / moisture that decreases the life of roof decking, roof underlayments (mainly non-breathable asphalt felt paper) and shingles. The SECONDARY purpose is heat relief in the summer.If you don't belive me, ask a manufacuter of ridge vents (Lomanco or GAF to name two). Or you could just google "Why Are Ridgevents Important" and you will see that ridge vents (exhaust) coupled with proper soffit vents (intake) will cause the Venturi effect and actually cause cooler, dryer outside air to be pulled into an attic. When the cooler, dryer air enters the attic, the moist air already present will be pulled through the ridge vents and removed in a continous cycle in the summer and the winter. Regarding hard data, this has been studied and put into use for years now. If you want to reduce heat in the attic during the summer months, then a radiant barrier is necessary (or you could use a new solar reflective shingle, ie. CertainTeed Solars of GAF Timberline Cool Colors).I followed your instructions, exactly.The very first link is a DIY video: "Your roof needs to be ventilated to protect the shingles and attic from excessive heat build up." And then shows how ridge vents let heat out. I would tend to think that would be the primary purpose of such venting: heat relief.Of the first page results, only these people seem to be as confused as you are: http://www.elocalroofers.com/sitePages/74/Ridge_Vents. If a roofing company told me this (all this talk about humidity but not one word on HEAT), I would kindly ask them to leave the premises immediately.Air that is at 100 deg F at the soffits is nearly as "moist" as the 130 deg F air being pulled out of your attic. It is all about exchanging really hot air (130+ deg F) with lesser hot air (100 deg F Houston in August). Moisture content will vary with the dew point, year round. Moisture content is a component of air. Both hot and cold air have some degree of moisture. And when the air is moved, the moisture goes with it.Please provide a link that supports your claim: "...the PRIMARY purpose of ridge vents (coupled with adequate soffit vents) is to relieve the attic of humidity/moisture... The SECONDARY purpose is heat relief in the summer..."I can find none that make that distinction. Link to comment Share on other sites More sharing options...
keepitlow Posted July 30, 2009 Share Posted July 30, 2009 I followed your instructions, exactly.The very first link is a DIY video: "Your roof needs to be ventilated to protect the shingles and attic from excessive heat build up." And then shows how ridge vents let heat out. I would tend to think that would be the primary purpose of such venting: heat relief.Of the first page results, only these people seem to be as confused as you are: http://www.elocalroo.../74/Ridge_Vents. If a roofing company told me this (all this talk about humidity but not one word on HEAT), I would kindly ask them to leave the premises immediately.Air that is at 100 deg F at the soffits is nearly as "moist" as the 130 deg F air being pulled out of your attic. It is all about exchanging really hot air (130+ deg F) with lesser hot air (100 deg F Houston in August). Moisture content will vary with the dew point, year round. Moisture content is a component of air. Both hot and cold air have some degree of moisture. And when the air is moved, the moisture goes with it.Please provide a link that supports your claim: "...the PRIMARY purpose of ridge vents (coupled with adequate soffit vents) is to relieve the attic of humidity/moisture... The SECONDARY purpose is heat relief in the summer..."I can find none that make that distinction.Well, here you go.http://www.lomanco.com/ventilationFAQ.html#01anchorhttp://www.lomanco.com/ventilation.html#whyVTanchor Link to comment Share on other sites More sharing options...
texas911 Posted July 31, 2009 Share Posted July 31, 2009 Or here's an option, foam insulation to close your attic all together. I'm thinking about doing this if its not too expensive, because it just sounds like an obvious solution. Heck I'm ready to splurge and get my whole house insulated with foam.http://www.a1foam.com/html/attic_application.html Link to comment Share on other sites More sharing options...
musicman Posted July 31, 2009 Share Posted July 31, 2009 Or here's an option, foam insulation to close your attic all together. I'm thinking about doing this if its not too expensive, because it just sounds like an obvious solution. Heck I'm ready to splurge and get my whole house insulated with foam.http://www.a1foam.com/html/attic_application.htmlJust hope your roof doesn't have a leak. this seems like it could mask the problem and result in rotted decking. Link to comment Share on other sites More sharing options...
Marksmu Posted July 31, 2009 Share Posted July 31, 2009 Just hope your roof doesn't have a leak. this seems like it could mask the problem and result in rotted decking.I had read somewhere, cant remember where, that if you spray your attic with foam, and its not designed for it originally that the condensation from the cool house will condense on the outside of the foam (its still hotter in the attic b/c of no ac) and the water will literally drip non-stop onto your ceiling in your home.I also recall reading that the spray in foam causes more mold build up here b/c of the humidity and total lack of circulation through the home. I would love to have a sealed foam house, but when I looked into it, if I am remembering correct, your home needs to be designed for it originally. Link to comment Share on other sites More sharing options...
TJones Posted July 31, 2009 Share Posted July 31, 2009 Not to mention that, with the foam, if there is a hailstorm and you get a damaged roof, you will NEVER be able to tell where the problem lies. Link to comment Share on other sites More sharing options...
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