cooling

Part 8 of our 15-part Q&A series on all aspects of green building from the publishers of HealthyHouseInstitute.com. Click here for the introductory post and furthur details.

Question: Why don’t you like fireplaces or gas ranges?

Answer: Actually, we don’t like most fuel-burning appliances—fireplaces, wood stoves, gas ranges, oil furnaces, space heaters, water heaters, boilers, etc. Many people think the reason we don’t like them has to do with fuel leaks. While oil or gas leaks certainly can pollute a house, we’re much more concerned with poor chimney function. Whenever you burn something, you have combustion by-products with which to contend. And, it isn’t healthy to have any combustion by-products indoors. The worst offenders are unvented appliances because they have no chimney whatsoever, and they dump combustion by-products directly into the indoor air.

You might think that if a fuel-burning device is connected to a chimney, the situation would be better. Well, in many cases it is—but in many cases it isn’t. You see, chimneys don’t always function correctly. The combustion by-products (which are warm) rise up through a chimney because warm air rises. You can actually measure a slight upward pressure (called a draft) inside a chimney. Problems occur when there's a negative pressure (that wants to pull in) within the living space that’s greater than the draft pressure (that wants to push up and out). If that’s the case, air can come down the chimney, and the combustion by-products can’t go up. When this occurs, they spill into the living space.

If there's a complete reversal of flow in a chimney (downward), it’s called backdrafting, and all the combustion by-products enter the house. In many cases, the draft is only partially affected, and some combustion by-products go up the chimney while some enter the living space. This situation is called spillage.

Backdrafting and spillage are actually quite common. In some houses they’re regular occurrences. For example, we’ve all smelled wood smoke indoors—smoke that should’ve gone up the chimney. Experts estimate that 50-80% of chimneys have the potential to malfunction.

As you can see from our green features list, we are going to use a geothermal heat pump for the heating and cooling of our house, as well as for our swimming pool. It is an extremely effective system that can be up to 2.5 times more efficient than a normal HVAC 12 seer system and uses very little electric. Add that to an air tight, well insulated SIP home, and you'll save yet even more money on cooling your home, probably 75-80% of what a stick frame/batt insulated/regular HVAC home would do.

There is one guy we talked to, J.D. Holt, who owns a 1650 sf SIP home in Austin, TX with a geothermal system to cool his house. In the summertime he pays about $60/month without being conservative with airconditioning. That is rather significant!

In Austin, there are only a handful of geothermal subs that can install geothermal. It is also a very effective system in cold weather climates. In Sweden, it is commonly used for heating, especially large apartment complexes.

At first, I had a hard time truly understanding the science behind a geothermal system and even harder to time to explain it to other people. :-) I copied a Geothermal FAQ from one of the subs we're considering as well as included a link to a video presentation... MORE HERE

Surprise surprise, reforestation begins at home--and it can even save you money. Green Options has publsihed an article by Paul Pruefrock today on landscaping for reduced home energy consumption. Ever notice how farmhouses in the middle of hot, dry fields are always surrounded by a ring of shade trees? Before there was air-conditioning, there was good, old-fashioned shade.

Pruefrock writes that planting trees can greatly reduce energy consumption in both summer and winter:

"In the summertime, steps you take to keep the outside of the house cooler can help lower (or maybe even eliminate) the amount of air conditioning you need to run. And providing evergreen plants to buffer the north walls, as well as the direction of the prevailing winter winds (often, but not always, to the west), can help stop drafts and help keep the house warmer in the winter."

You can find tree-planting instructions here, and at arborday.org. To learn more about trees that will grow quickly to provide shade and insulation, visit Fast Growing Trees, and if you want to feed your family in the bargain, you can find more information at the Fruit Tree Planting Society.

The End of the Air Conditioner

During the recent renovation on my personal kitchen, I had an interesting discussion with my plumber about this revolutionary wallboard material which acts like a major air conditioner without power requirements. I thought what in the world was he talking about? In fact, he was planning on building his new “Maine camp” out of this material which would allow him to lower his heating bill in the winter and eliminate his cooling requirements, i.e. his AC, in the summer. Interested, so was I.

Where will it be used? I hope in my next house reno project!

For futher information, BASF recommends checking out

http://www.micronal.de

http://www.ise.fraunhofer.de/welcome_english.html

http://en.wikipedia.org/wiki/Phase_Change_Material

or Contact:
Hartmut Lang
BASF
Tel: (973) 426-2843
E-mail: langh@basf.com

The first time I saw this method of passive cooling was in a house on the island of Mallorca (it worked! It really worked!), the architecture of which was heavily influenced by the Moors..... it is an ancient idea going back in the mists of time, but an absolutely relevant one in this day and age.

Passive Air Conditioning, from The Farm. Don't know The Farm? You're in for a hippie treat!

Passive Cooling, from PermacultureTokyo Blog

Passive Cooling Techniques, from Build It Solar - I've written about this site before. The last word in green technologies. Go to their main page and get a real education.

I have an arbor - a ramada, we call it here in the Southwest - with a grapevine growing up over the patio on the southwest corner of my house. It keeps the hot summer morning sun from heating the windows and the walls in that part of the house, filtering the harsh light and providing a leafy green cool that is soothing and refreshing. The birds (and, once in a while, a raccoon) love the grapes - I don't get very many. Then, in the fall, the leaves fall off, the sun shines through the windows, and the inside space is warmed and lit with bright light.