energy star bullcrap

[Tony Mount]

Can anyone tell me how much money a builder makes building a energy star house? A builder here in Oklahoma says he is building green energy star homes that are super insulated with 2x4 walls and R-30 blown insulation in the attic with UV windows but here is the kicker.... 1600 sq ft house with 2 ton A/C and a 45,000 BTU gas heater. Come on I don't see a custom engineered high efficiency heating unit that small being cheaper to operate than a mid efficient heater at 80,000 BTU. what do you think? Will the heat and air run all the time?

[Bruce Breedlove]

Tony,

From your words ("energy star bullcrap") it is apparent that you are not exactly open to the idea of high efficiency homes.

I don't know if the house you described could be heated and cooled by that HVAC system. But it very well could.

I recently toured a less-than-net-zero house in Boulder. (A net-zero house produces as much energy as it uses. A less-than-net-zero house produces more energy than it uses.) I forget the exact details but the house was around 4,000 SF and does not even have a furnace because it does not need one. It does not need a furnace in Boulder, Colorado!

The house has 2X6 walls with 7" of icynene insulation. (The extra 1 1/2" of insulation comes from using a hat channel run perpendicular to the studs for a thermal break.) The walls are double 1/2" drywall for a higher thermal mass. Windows were triple pane. The house is SUPER tight (something like 0.06 air changes per hour (ACH)). It has 12 or 13 solar collectors on the roof supplying hot water to a 6,000 gallon, super insulated storage tank in the basement. It also has a good deal of PV (photovoltaics) to generate electricity. (The electric meter runs backwards when more electricity is generated than is used. The owner gets a check from the electric company every year.) The house is heated by radiant hot water heat in the basement slab. The house will not drop below 68 degrees with cloudy skies and zero degree outside temperatures for 3 days straight. The only complaint was the stored hot water was not quite hot enough for the wife on those super cold, cloudy winter days so the builder added a 10 gallon electric water heater to boost the water temps up a few degrees. Oh, and the builder lives in the house. It was VERY interesting and VERY cool.

edit - Below are some photos I took during the tour.

[Rick Hurst]

I would be suspect of a 2-ton unit on a 1600sq.ft. home in Oklahoma. Could be very well undersized.

rick

[Brandon Whitmore]

Will the heat and air run all the time?

My house was built in the 60's, so I wouldn't call it efficient by any means. The subfloor is half insulated at R-30 -- unfinished project. The attic now has R-48 or more. I've got mineral fiber, followed by cellulose, followed by blown in insulation up there. There's single paned windows with storm windows added, and little wall insulation. Let's just say my house is a work in progress.

During our last near week long cold snap which was probably 10-20 deg.(cold for our area) night/ day, my 42k btu high efficiency furnace had no problems heating the house, and did not run constantly. I'm sure it gets much colder over there, but the house should be much more efficient.

[Bob Spermo]

The only proper way to size the units is by using Manual J (and Manual D for the ducts) (and Manual S to get the appropriate size for the climate). Homes that are constructed tighter today need smaller units. I believe more units are oversized and thus less effective at taking moisture out of the house. We should not use tonnage/BTU vs square feet as a sizing criteria.

[Kevin Luce]

The only proper way to size the units is by using Manual J (and Manual D for the ducts) (and Manual S to get the appropriate size for the climate). Homes that are constructed tighter today need smaller units. I believe more units are oversized and thus less effective at taking moisture out of the house. We should not use tonnage/BTU vs square feet as a sizing criteria.
I agree. A buyer for a new constructed house had a home inspection. The home inspector questioned the BTU's of the heating unit installed. The buyer had two heating companies out using the size of the house to determine the BTU's of the furnace and both of them reported the furnace was too small. That and some other problems resulted in a lawsuit. The company that installed the furnace referred back to their information. The company that made the furnace also got involved and the result was the furnace was sized properly. That part of the lawsuit was dropped.

Using the size of the house only to determine if the furnace is sized properly can be inaccurate.

Note: The same furnace was used on all the other duplexes and nobody ever complained that the furnace was not heating properly.

[Bruce Breedlove]

Using the size of the house only to determine if the furnace is sized properly can be inaccurate.


Very true. I wonder what size furnace the "rule of thumb" would say is needed to heat the less-than-net-zero house in Boulder that has no furnace.

[Darrell Covington]

Yes there are some builders building energy star homes in Oklahoma. Yes, the HVAC units are sized accordingly by qualified engineers. The sizing of the units in Oklahoma are determined by the cooling load, not by the heat load, since we have more demand in the cooling season than in the heating season.

Any engineer or qualified heating and air conditioning contractor will tell you you are better off being slightly undersized in the cooling season. This will allow the AC unit to adequately de-humidify the house as well as cool the air.

[chris mcintyre]

Can anyone tell me how much money a builder makes building a energy star house?


I'm not sure I understand what you are asking, but if you are asking how much more a builder makes, it can be fairly expensive (percentage wise) on a small house. So if it is a spec house you are lucky to recoup the investment, but it will defiantly sell the house quicker, people seem to love the "energy star bullcrap".



...building green energy star homes that are super insulated with 2x4 walls and R-30 blown insulation in the attic...


It doesn't sound like an energy star house but would be easy enough to find out at the energy star website. You can use energy star practices but to be certified you must use a third party rater.

BTW building green and energy star are two completely different animals.

[JB Thompson]

An acquaintance of mine builds energy star homes. When the HVAC company properly calculates the Manual J in these homes, the HVAC units are almost always smaller. I did draw inspections on these homes for the bank, in the Texas summer, and I was very impressed with the comfort in the home and the attic!!

[chris mcintyre]

An acquaintance of mine builds energy star homes......... the HVAC units are almost always smaller.

Agreed.



I was very impressed with the comfort in the home and the attic!!


Which tells me that this was not an attic with R-30 blown in insulation.

[JB Thompson]

Agreed.



Which tells me that this was not an attic with R-30 blown in insulation.

I should've clarified....foamed insulation:)

[Lisa Endza]

InterNACHI Receives U.S. EPA Approval to Use ENERGY STAR® Logo (http://www.nachi.org/home-energy-inspection-energy-star.htm)

[Rick Cantrell]

InterNACHI Receives U.S. EPA Approval to Use ENERGY STAR® Logo

The title says it all
energy star bullcrap

[Lisa Endza]

Planet InterNACHI... resistance is futile.

[Benjamin Thompson]

Hey Tony, It is BS. I bought a Samsung energy star rated dishwasher and found out after I installed it, it has NO DRYING CYCLE! The dishes are wet until you dry them with a towel, but they got their energy star rating.

Just to clarify, Energy Star is BS because it doesn't compare apples to apples. For instance, there is no such thing as an energy star electric water heater (possible exception of a heat pump) because they are all 100% efficient, so why aren't they ALL energy star rated?
Bottom line is, there is no free lunch. You reduce the input, you reduce the output. Energy star home in Colorado without a furnace, I don't think that's going to work too well.
Where I am, they are touting "geothermal heat pumps" (nothing more than water or ground cooled coils) at a cost of $40000 or more. How long does that take to pay back without government subsidies? Longer than the life of the unit I expect.