Category Archives: Improvements for Energy Efficiency

Can A 13 SEER AC Unit Make Sense For Energy Efficiency?

I’m visiting this week with some former Austin neighbors who now live at 8,000 feet elevation in the mountains above the town of Ruidoso, NM. They just had a new house built and, being curious about their new HVAC system, I took at look at the outside AC unit. When I looked at the energy efficiency rating and saw only 13 SEER, my first thought was this: their builder ripped them off! Then, I remembered my hosts saying that, even thought it’s mid-August, they had only run their AC system for a few hours on two afternoons all summer. Luckily, I had not embarrassed myself by thinking out loud.

My next stops were under the house and in the attic. There I saw a gas furnace rated at 97% efficiency (the efficiency range of new furnaces is about 80-98%) and super thick insulation. Thinking it though, and knowing about the “whole house” approach to energy use and conservation, the reasons for their choices became clear. Due to the high elevation, colder winters, and minimal need for air conditioning, they spent proportionally more on passive solar design and windows, high-efficiency heating, and extra insulation to retain more heat.

Coming from Austin, with its long, oven-hot, subtropical summers, at first it seems a bit ironic that relatively low efficiency AC equipment of any kind can make sense.  However, when considering what my friends did with the extra money that higher efficiency equipment would have cost (or other energy use that was avoided in not generating the income to buy overkill efficiency) the interconnections do get interesting.  The focus of this post is on a new system. For a list of way you can lower utility bills and energy usage on your existing equipment, visit this page.

Wise AC and Heating System Buyers Know: It’s Not About the Box

Today, while reading in an interview in a HVACr trade journal, I read a quote that summed up an important point:

It’s not about the box, it IS about the whole house

In this case, the “box” is the new AC and heating equipment you are thinking about having installed. And the whole house (actually the part HVAC insiders call “the envelope”) interacts with the outside elements to determine how comfortable you are inside, how hard your AC and heating equipment has to work, and how much you pay (or save) each month in utility bills.

Here’s a real life example from a reader who sent an email to us recently.

This fellow lives in the northeast U.S., and was quite surprised when his local AC contractor discouraged him from buying the top of the line, most efficient system. Rather, the contractor advised him go for the 16 SEER A/C unit, and to take the extra $2,000 the most efficient AC was going to cost and use that to add insulation to his attic and seal up leaky walls and electrical outlets.  Although the summer cooling needs of this northeastern state are lower than central Texas where we are, the same principle applies everywhere:

For each home or building and its climate, there is an optimum mix of heating or cooling efficiency attributes and energy efficiency improvements that could be done to the “envelope” that interacts with the outside air.

Since you only buy an new AC and heating system every decade or so, you don’t have to know everything about this topic. Your best bet is to be aware of the big picture and ask the right questions. This way you will find a local contractor who uses best practices (training, certifications, experience & business practices) and takes the “whole house” approach.

Let us hear from you if you have experiences to share along these lines

Nanotech Aerogel Insulation and Energy Conservation In Homes & Buildings

A couple of days ago, while searching on Google for new developments in Heating and Air Conditioning, I found two new things: First, a new way to read news articles, called FastFlip. I thought our readers might find it and the second subject, Nanotech Aerogel Insulation, of interest as it realates to HVAC.  Before going further, I’ll add that, after blogging about difficulties with high energy bills, defective drywall, and other challenges homeowners are facing currently, it is fun to write about a topic that could be a breakthrough in energy conservation.  We all could use a break and enjoy more indoor comfort and lower bills, right?

First, a useful new search tool, Google FastFlip

Google Labs has a search product in beta called FastFlip. It’s simple to use and appears to be built to deliver relevant information from trusted sources in a format that is easy to read.  All you have to do is enter the topic on which you want to read the news. The search results page loads with thumbnail views of recent online publications that, to us, appear to have been vetted for quality journalism.  I like FastFlip a lot and hope it becomes a full-fledged service like Google News or Google Images. Now on the heating and AC related topic I found.

SuperInsulating Aerogels in Home Insulation

In the article from Popular Science (link below) there is a brief history of aerogel technology.  It was discovered about 70 years ago, but due to high cost and other limiting factors, aerogels were mostly used by NASA in aerospace, or in deep sea pipelines and other extreme environments or applications. Rather than try to cover the whole topic in one blog, I’ll give a brief overview and provide links to the articles themselves.  On these websites, there are several brief video clips showing the amazing insulation properties of aerogel.  If aerogels work as indicated, they could be a game changer in energy conservation for homes and buildings. The article in Popular Science online has a link that leads to an article in Ceramic Tech Today (link also available below) that shows aerogel being used in a building application. This article has comparative charts on insulating properties of aerogel and more conventional types of building insulation, and lists companies that are making aerogel products that related to home energy conservation,  heating and air conditioning.

Links related to this topic:

Popular Science Magazine Online


Cabot Corporation_nanogel


Tax Credits to Make Homes and Buildings More Energy Efficient for Heating and A-C

Listening to National Public Radio yesterday, I heard a report that discussed the use of tax dollars to renovate schools to make them more energy efficient. Of course, this sounds like a good idea. A follow up search on Google delivered the Schools for Energy Efficiency website. According to this source, one-third of the energy currently being consumed in schools is not used efficiently, and annual energy usage for heating and air conditioning costs up to $250 per student. This means that schools spend more on energy for heating and A-C than on books and supplies!

A similar situation exists with home air conditioning and heating. The condition of the envelope of the home (windows, doors, insulation, vents and the parts of the home that interface with the outside environment) has a lot to do with how well any heating or A-C equipment will heat or cool inside. The federal government still has programs in place to help homeowners make energy efficiency improvements, and a good place to start reading about them is on the Energy Star website. There, we found the following statement:

Tax credits for these residential products, which had expired at the end of 2007, will now be available for improvements made during 2009. However, improvements made during 2008 are not eligible for a tax credit.

To learn more about these programs you should ask your tax advisor and a local heating and A-C contractor. They should know which federal, state or local programs are available in your area to offset some of the costs of home improvements for energy efficiency.

If you know of a good case history or other example of home or building renovations to save energy in your area, please tell us about them in a comment or email them to us.