[bamx2]

I want to add more under eave ventilar ot reduce the tmeperature in the attic of my house. The temperatures reach close to 125 deg of on a hot summer day. The extreme elevated heat in the attic only became apparent after I recently had several trees removed (lost a lot of shade) . To complicate vinyl "hidden vent" soffit material was install several years ago. I remember the contractor removing the metal vents and clearing the openings prior to installing the vinyl material (he showed me). Anyway, I now have the heat problem. I have run the numbers and found that there was never enough intake vent area to begin. I am looking for advice on the most efficient and least expensive way to increase the intake area. Removing and re-installing the vinyl soffit material is complicated and expensive. I was thinking of cutting holes though the existing vinyl soffit and plywood underneath in new evenly spaced locations and covering the hole with white alumininum soffit vents. The holes would mainly be in the upper story (2 story houses), This seems like that it would wore but would it be noticeable ?. Any other options short of pulling off the vinyl and not those littile 4 in round vents ?It would take way too them .-Thanks

http://i33.photobucket.com/albums/d70/rkpatt/270housepics/IMG_20160616_200650333_zpsb5umepat.jpg

http://i33.photobucket.com/albums/d70/rkpatt/270housepics/IMG_20160616_200623064_zpststucw4i.jpg

http://i33.photobucket.com/albums/d70/rkpatt/270housepics/soffit vent 715751005180_zpsmwe2mbsr.jpg

 

[PandJ]

You may want to consider a roof fan vent. Solar ones are great easy to install. Guessing would negate the need to add vent's since active ventilation from fan would increase flow tremendously.

I've had a solar fan for years and it's still working great with no maintenance. Just thought I'd share

 

[joecaption]

Your suggestion would look like poop and there would be huge gaps where the beads are.
The right way would be the way your trying to avoid.
Your siding guy took the easy way out, he should have removed all of that plywood before installing the soffit.

 

[Bud9051]

I was unable to see your photobuckets, probably my problem, but Joe is correct. A hack job will not work as well and will not only look bad but reduce the value of your home. Geting up there is probably the bigger problem, but once you solve that, removing those vinyl pieces should be easy. Then cut more holes or stripd out of that plywood and reinstall the vinyl.

Now, 125° is not hot for an attic. Even with better venting you will not see the temp much lower than that. best defense against a hot attic is air sealing and more insulation. The air sealing is also important if you consider an attic fan.

Bud

 

[bamx2]

Thanks for the replies far. I do have an opertingpowered roof vent. I do have lots of insualation . Tne main problem for me is the 2nd flood HVAC is located in the attic and wit is now under capacity due increased heat due loss of the shade (paristic heat heat gain) and I wonder how badly the heat is destroying the roof shingles, Cooling was adequate before the trees were removed. Now 2nd floor temperature cannot get below 81 deg F in afternoon on a hot sunny summer day with temperature is in the mid 90s+. We are getting by with fans and a window unit in one room that is used as office day as an interim measure. No problem at night. Should I then not waste my $ on redoing the soffits and just upgrade the HAVC equipment and ducts (add another 1/2-1 ton and new R-8 insulated ducts) ? The HVAC system is 18 years old but functioning perfectly (coils cleaned, pressures normal etc ) but is the equipment is nearing the end of its life. - Thanks

 

[Bud9051]

Maybe this link will help. http://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-attics

If the tires on your car are so low on air that it is slowing you down, you could buy a new larger engine to move you faster. OR, you could fix the tire problem.

AC in the attic and r-6 on the ducts and I suspect half of your cooling capabilities are lost in the attic. The link above will offer you many other links and a lot of good information and perhaps get you improvements back on track.

Bud

 

[bamx2]

Thanks for the link.

Yes, the heat in the attic is severly impacting the HVAC.

I suspect that the R-value for the existing duct insulation (foil backed fiberglass 40 years old (and appears to be compressed) is <<R-6.

Moving the unit and ducts and unit out of the attic is the best solution for energy efficiency but not practical in this situation (architectural reasons) or economically feasable.

Maybe this link will help. http://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-attics

If the tires on your car are so low on air that it is slowing you down, you could buy a new larger engine to move you faster. OR, you could fix the tire problem.

AC in the attic and r-6 on the ducts and I suspect half of your cooling capabilities are lost in the attic. The link above will offer you many other links and a lot of good information and perhaps get you improvements back on track.

Bud

 

[Bud9051]

The author of that link recommends bringing the attic space into the conditioned space, but that IS expensive. But insulation and duct sealing efforts are not too bad. If those ducts were insulated 40 years ago, then they certainly were not air sealed. Sounds like a good place to start, removing that old insulation, air sealing all ducts and the unit, and then applying more and better insulation. Leaky ducts also provide an air escape path during heating season, assuming you have a heating season . Here is a link on air sealing which should include some duct work. Been awhile since I read through it.
https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/TBC_Guide_062507.pdf

Bud

 

[KurtP]

Another option to consider is radiant reflectors below roof sheathing. Leave a 1" or so air gap which can also serve to channel the heated air out the ridge vent. The importance of understanding radiant heat and managing it should not be overlooked.

 

[Dave Sal]

I had a similar issue when I first bought my house. There were wood soffits, and no venting, and the roof in the upper level only had two static vents. The upper attic temps during summer were extremely hot. I ended up adding a powered attic fan in place of one of the vents, and then added about 26 soffit vents. Now, the attic temps stay around 105 on a really hot sunny day, mostly due to the increased air intake plus the hot air being exhausted by the fan.