Energy Efficiency / Hunter Homes (Grant: rental, new house, construction)

[MyloXyloto]

My family recently moved into one of the Designer Homes from Hunter. We've been in the house for about 2 months (love the space, location, and especially the layout...I've had many people over in the last few weeks that love the open floorplan). Only had one minor problem, which was the threshold on the garage door coming apart, which they fixed the day I called them.

Anyway, when we were looking around, we got the entire "energy efficiency" / radiant heat barriers on the roof / "spiel" from their realtor...he's a nice guy, but he IS a salesperson. I'm a natural skeptic, and thought that was just some closing tactic, etc.

Well, we moved from a 2,060 sq. ft. ranch with a crawlspace that was built in 1996...not a new home, but not that old either. Our average utility bill from Hunstville Utilities in August would be around $340. We like to keep the house cold...usually 73 during the day and 72 at night.

Our new home is 3,300 sq. ft. 2 story. I have FEARED the utility bill because the house was so much larger and we like to keep it cool. We got the first one for a full 30 day period last week...$234!!!!!. I was floored with excitement. That was even with us having the doors open a lot with moving furniture in, etc.

I'm not a "go green" kind of person, but I'm a believer in this stuff now.

[FatTails]

Let me guess. The radiant heat barriers use NASA technology from the space shuttle.

Interesting post, but I would think all new construction is using the latest and greatest in energy efficiency. Being the cynical guy I am, I would offer the possibility your energy savings come from an A/C with a higher SEER rating.

[LCTMadison]

Your past utility bill was WAY high, my house is much bigger, a two story (2 units), and I have never had a bill higher than $225. Radiant barrier roofing (depending on WHAT they use) is a good addition and helps (for the record, I don't have it), but like nerdtron said, it is more than likely the newer HVAC system, as they are much more efficient now than back in the 90's.

[CoreLysium]

I have a 2200 ft house built in 1982 with a 14 foot ceiling in the main room and mine run about $220ish also.

I've been tempted to put the radiant heat barrier on the joists of the roof, but I can't see that it'd break even very quickly considering the cost of materials and the money value I put on my time spent crawling around in the attic.

Also, those radiant heat barriers usually have warnings that they can melt your shingles. I have no idea if this is true, but that would suck badly.

[ghostrider42]

I had a DelTec built two story each 1500sf each = 3000sf. The most my elec bill was $200 - that was in Kalispell, Montana - where the snow that fell in November was still there in May. Each wall/window unit was a SIP - 8" thick - R30. The metal roof was spray insulated to R40.

[MadNick]

I have 2500 sq ft built in the 1960's and the electric portion of my bill rarely tops $100 and my AC unit is over 20 years old and sucks power like crazy. Granted I have gas hot water and heating, but still... gas is only like $10/month in the summer.

I don't have a radiant heat barrier; it didn't appear to be cost effective versus insulation. I do have insulated exterior walls (the original rock wool), insulated ducting in between the floors (former owner), a partial basement and I blew 12" of insulation into the attic. I also insulated over the garage even though it's not in conditioned space and insulated the garage doors.

I'm pretty sure the $600 I spent on insulation a couple of years ago has paid for itself already. I'm not sure about the garage doors but considering how hot it gets in a south-facing garage, it might have.

I keep the temp at 78-80 in the summer which is very comfortable for me with the ceiling fan on low. Since I work at home, I don't spend all day shivering in a 65 degree cubicle, but I also can't bump up the temp during the day to lower costs. My neighbor is a nurse and she just can't adapt back and forth from 55 degree hospital temps so she keeps her house very cold.

$234 for that temp setting and that size house sounds pretty good to me, even it it has been relatively mild this summer. If I put my thermostat that low I'm not sure my AC would ever stop running!

[FatTails]

Well, here's my take on these barriers. I am from Arizona, where there is not a cloud in the sky 90% (literally) of the year and the desert cools to a crisp 100 degrees at 2am during the dead of summer. I researched HVAC SEER ratings, these barriers, higher grade insulation, etc. I remember two things. First, the higher efficiency HVAC would give me the most bang for the buck, followed by extra/upgraded insulation. The barrier, on the other hand, had a break even time of close to a decade. While the DOE estimates the barrier will give a 5% reduction in energy costs, the state (AZ) and the power utility both believed the barrier was an ineffective method unless you had extremely poor insulation. In the end it didn't matter because I moved here, but had I stayed longer, my money would have gone to a new HVAC. If the builder throws it in I certainly wouldn't decline it, but I also wouldn't pay extra for it. In Alabama where the humidity is the real killer in the summer, I would be even more inclined to opt for better HVAC/insulation.

[bmrisko]

We added LP Techshield radiant barrier (basically foil-backed OSB roof decking) to our home during construction as the additional cost was negligible in the grand scheme of things and the PBP was less than 10 years. I can't tell if it makes a difference on the bill as I have nothing to compare it too, but I will say our attic space seems noticeably cooler than other attics I have been up in during the dead of summer. Our electric bill averages $115, but our home is a 3,000 ft^2 single story. As mentioned above, the newer HVAC unit is likely the major reason for a lower bill. Also, modern low-e windows will help. One other thing I did is tape up the openings around all the HVAC registers as they are in our ceiling. Basically, unscrew the vent and tape over the gap between the duct and drywall, then screw the vent back in and you can not see the tape. I think this cuts down on heat seepage into the attic and has also seemed to minimize dust in the house, which my wife thinks is a great added bonus. The same idea can be utilized on recessed lighting and bathroom fans.

[RatSnake]

We have LP Techshield too in our new home.

Our previous rental - had a brand new HVAC. Total sq footage was 2400. We always keep the thermostat at 78 in the summer. Lived there for almost years.

I kept an excel file detailing KW usage even plotting the average monthly temps.

Old Home New Home Differential
May 1921 1113 -42%
June 1691 1758 + 3%
July 1514 1626 + 7%
Aug 1773 1575 -11%

Thermostat 78 78
Total Area 2400 3400

The HVAC SEER rating for both homes were the same (13).
I should also add that the old home was in a treed lot - the house was shaded by trees on the north, south and east.
The new house is not on a treed lot. There is no shade from trees on all sides.

[LCTMadison]

Originally Posted by bmrisko

We added LP Techshield radiant barrier (basically foil-backed OSB roof decking) to our home during construction as the additional cost was negligible in the grand scheme of things and the PBP was less than 10 years. I can't tell if it makes a difference on the bill as I have nothing to compare it too, but I will say our attic space seems noticeably cooler than other attics I have been up in during the dead of summer. Our electric bill averages $115, but our home is a 3,000 ft^2 single story. As mentioned above, the newer HVAC unit is likely the major reason for a lower bill. Also, modern low-e windows will help. One other thing I did is tape up the openings around all the HVAC registers as they are in our ceiling. Basically, unscrew the vent and tape over the gap between the duct and drywall, then screw the vent back in and you can not see the tape. I think this cuts down on heat seepage into the attic and has also seemed to minimize dust in the house, which my wife thinks is a great added bonus. The same idea can be utilized on recessed lighting and bathroom fans.

Taping up the ducts is a great tip, never thought of that! It really must work on dust because your house is new and typically you get a lot of dust in new homes.