Seattle Home Inspector's Blog

head_left_image

Nature's air conditioning

 

Grape shadeHow long have we been building houses?  A lot longer than we have been air conditioning houses.

Well we have certainly done things to keep warmer and dryer for thousands if not 100’s of thousands of years–but we have also done things to keep them cooler as well.

As a designer/builder for most of my adult working life, I have marveled at how ignorant we are of how to accomplish keeping warm, dry and cool.

We now have air conditioning systems that allow us to live in places where not too long ago it would have been considered uninhabitable–or at least inhospitable.

We have long had the knowledge to mitigate the use of air conditioning to some degree and yet we simply choose to turn down the knob on the thermostat.

Today I just want to talk about a few “passive” things that can be done to greatly decrease the use of actual mechanical air conditioners.

First and most important is house design and orientation. Obviously if we build a house and make all the south facing walls floor-to-ceiling glass, with no roof overhangs, we can expect to find ourselves inside a solar heated oven. Just providing a roof overhang to prevent the sun from hitting the windows directly can go a long way to turn the oven down a bit. By eliminating ground and other surfaces that might reflect the sun’s rays into the home can also be an improvement.

 

Living in the shade

Even these Native Americans made an attempt at basic principles

Of course reducing the amount of glass itself will make the most difference because then the walls themselves can be better insulated. This brings us to the huge topic of insulation in general. There is nothing like highly effective insulation in the walls and ceilings to keep the heat out of the house. This is not as simple as it may seem because heat is always attempting to move to cold and make balance. When it is 95 degrees outside, all that hot air is just hungry to gobble up our pathetic little bubble of coolness. So our air conditioners have to work their butts off to maintain that bubble of coolness.

While today I do not want to go into how I think houses should be built to eliminate the need for air conditioners altogether in many areas, I want to talk about ways we can deal with adverse conditions in our older homes in passive ways. While these things will not reduce your need for air conditioning in some areas it may greatly reduce the amount they may have to run. It may mean in some hot humid areas you might have to add a dehumidifier to make up for what the AC used to do.

The short story in all of this is to insulate your house as much as practical and use good air sealing type insulation–anything longer and we are into the full fledged novel.

One of the most important things you can do, if you live in an area where the nighttime temperature drops even 20 degrees between daytime and nighttime, is to change the air in the home and lower the thermal loading that has built up in the home during the day. The house is then closed up during the day to keep the nighttime cooling in and then the process simply repeats itself. In an average size house, even a simple window fan in a window on one side of the house and a window open on the opposite side of the house can accomplish this goal.

I cannot stress the importance of roof overhangs to keep the sun out, but in older homes that is not likely going to be possible.

In my own house, built in the early 30’s, the overhangs are insufficient to keep the south facing windows from overheating the house in the summer. So a simple thing I have done is to shade the windows with a grape arbor–the one plant now creates shading of most of my south facing windows and makes an amazing difference, and of course provides grapes in the fall.

grape shade

While we certainly do not get as hot as lots of areas of the country, my house certainly never needs any mechanical air conditioning. The attic has a ton of cellulose fiber insulation, the walls have minimal insulation limited by the 2×4 wall thickness, and we put a fan in an east window at night and open up a west window–on those occasional really hot days.

Before the days of the grape arbor, we use to have to do the fan approach a lot more.

If you have a house with a basement, you can open up a basement window (as the path to the upper fan in the window) and get the benefit of the cooler basement to improve the cooling of the interior space during the nighttime. Accessing the constant ground temperature is another thing that can have a huge impact on minimizing the mechanical cooling needs of the home.

A huge number of homes across America could benefit from this passive approach to improving house comfort and energy efficiency.

Charles Buell, Real Estate Inspections in Seattle

* * * * * * * * * * * * * * * * * * * * * * * * *

Seattle Home Inspector

 

The Human Rights Campaign   QR code for Charles Buell Inspections Inc  ASHI.org

 

WA State, Home Inspector Advisory Licensing Board

Comment balloon 19 commentsCharles Buell • July 22 2017 02:12PM
Nature's air conditioning
share
How long have we been building houses? A lot longer than we have been air conditioning houses. Well we have certainly done things to keep warmer and dryer for thousands if not 100’s of thousands of years–but we have also done things to keep them… more
They Buyer's Due Diligence
share
There seems to be a general misconception among some home buyers that the hiring of a home inspector is the completion of their due diligence, when in many respects it is just the beginning—or at best just part of the process. The home inspector will… more
Why is your Attic Access smiling at you?
share
People love to install pull down stairs as the means of attic access, Stairs tend to make the attic space more useful as one is not teetering on a step ladder to get things up and down. Before I go further in this discussion, I want to state that… more
Myths of fire-rated walls & doors between the garage & the…
share
A common mistake that home inspectors make when inspecting single family residences is related to opinions stated about the requirements for separation between the home and the attached garage. Their comments often leave them “out on a limb” when… more
Details, details…..
share
A house I inspected recently had been remodeled. The detailing was excellent. The whole house had been resided with cement board siding and had all the correct flashing details EVERYWHERE! The painting job was equal to the siding installation. Just… more
Where did the mail slot go?
share
It seems like there was once a time when almost every home had a mail slot. Often it was in the front entryway door or sometimes built right into the wall where there was a place inside the entryway closet to collect all the mail. It was a familiar… more
Why is my garage ceiling so “tired? ”
share
While I do not know the exact makeup of all of this black marking of the ceiling on one side of the garage, I am quite sure that a very large percentage is bits of tires and brake linings from the highway on the other side of the fence. The boiler… more
It is new construction---why would I need an inspection?
share
To answer the title's question, I wish I could say, “Just because. ” I know that is not going to convince anyone though, so I will give some examples of why EVERY home needs an inspection in the context of a real estate transaction--even new… more
But that is why they call it an Inspection.
share
It seems at times, home inspectors are damned if they do and damned if they don’t. What should report write-ups about home defects look like? If you talk to 100 agents and 100 inspectors you will likely get 200 answers. If you talk to clients, you… more
Sweaters and windbreakers.
share
Everyone knows if you want to stay warmer when it is really cold, your sweater will become much more effective if you wear a windbreaker over it. This is because the windbreaker decreases air movement into the materials that are keeping you warm--… more