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Climatological Overview of Kittitas Valley

The Kittitas Valley region is "heating" dominated.  It is important to understand the basic climatic data to accurately calculate the heating and cooling loads needed, avoid potential moisture problems and calculate solar heating gain.

Ellensburg has annual average total precipitation of 9 inches and 28 inches of snow.   Ellensburg has 6645 degree heating days and 332 cooling degree days. The coldest day of record is -29F in 1927.  

Cle Elum has annual average total precipitation of 22 inches and 77 inches of snow. Cle Elum has about  6926 heating degree days and 219 cooling degree days. The coldest day of  record is -21F in 1950.

Yakima has 5967 heating and 458 cooling days with and average annual day and night relative humidity of 60%.  Their coldest day was  -24F in 1919.

In the winter this region has approximately one day out of three that is clear or partly clear (the other 2 out of 3 days are cloudy). During the summer 3 days out of 4 are clear or partly clear.

Per ASHRAE definitions, this region is classified as COLD; that is, more than 4500 heating degree day but less than 8,000 (severe cold!).

What is a heating degree day?

Early this century heating engineers developed the concept of heating degree days as a useful index of heating fuel requirements. They found when the daily mean temperature is lower than 65 degrees, most buildings require heat to maintain an inside temperature of 70 degrees. The daily mean temperature is obtained by adding together the maximum and minimum temperatures reported for the day and dividing the total by two. Each degree of mean temperature below 65 is counted as one heating degree day. Thus if the maximum temperature is 70 degrees and minimum 52 degrees, four heating degree days would be produced. (70 + 52 = 122; 122 divided by 2 = 61; 65-61 = 4.) If the daily mean temperature is 65 degrees or higher, the heating degree day total is zero. The cooling degree statistic is the summer counterpart of the heating degree day.

Heating a house

There are several conventional strategies for heating a house and numerous types and manufacturers of mechanical heating equipment. The smart choice is a correct match of the size of the heater to the heat loss calculations of the building. Distribution of the heat throughtout the house is also calculated. Generally the higher efficiency heaters are less expensive in the long term. The economic break even period is 3 to 6 years for a more expensive but higher efficiency heater than an initially cheaper but less efficient one.

Some common choices of heating types in our region are forced-air, hot water radiator, hydronic, electric baseboard, and gas log stoves.

Forced-air unfortunately stirs up dust and keeps allergens suspensed in the air. This is the worst type of heater for anybody with allergies or asthma. Hydronic systems heat the floor and the heat rises to warm the room - no more cold floors to put your bare feet on.  Hot water or steam radiator heat has been around for a long time and is still a very good method of delivering heat. The radiators radiate heat much the same way as a hot fireplace would but without the smoke and flames. The radiators are great to set on after coming inside from outdoor winter activities. Electric baseboard heat is clean and healthy and the equipment is very cheap but the cost of electric is the higher than natural gas, propane, oil, wood, etc. In the long term, electric is usually the most expensive.

If you built a high performance "not so big" house of around 1,200 square feet, it should be able to be heated for a dollar a day average. In this scenerio, electric heat begins to become competative.

Solar heating

Passive solar heating uses traditional building elements like insulation, south-facing glass, and massive floors to achieve comfort heating. These beautiful, comfortable and healthy living spaces can be built for no extra cost while increasing affordability through lower utility payments. They also keep investment dollars in the local building industry rather than transferring them to short term energy imports. Passive solar buildings are better for the environment while contributing to an energy independent, sustainable energy future.

Advances in glass technology have perhaps been the single largest contributor to building efficiency since the 1970s and they play an important roll in solar design. Some window advances include:
    * Double and triple pane windows with much higher insulating values.
    * Low emissivity or Low-E glass employing a coating which lets heat in but not out.
    * Argon (and other) gas filled windows that increase insulating values above windows with just air.
    * Phase-change technologies that can switch from opaque to translucent when a voltage is applied to them.

Cooling

Because of our climate only the worst planned houses require air-conditioning. Air-conditioning is expensive to buy and expensive to operate. Proper planning can almost completely eliminate the need for this equipment in a house in our region. Some ideas to reduce summer heat -

• Extend roof overhangs enough to shade the windows during summer.
• Install glazing that has reflective coatings.
  
• Install awnings over windows
• Plant trees or shrubs to block the sun.
• Close windows during heat of day and open in evenings.
• Install a ceiling fan.
  

Swamp coolers are generally not a good idea because they can harbor mold and mildew and these can cause health problems. If you use one, please follow the cleaning requirements.

A properly and carefully though out building plan that includes high performance insulation and glazing specifications along with landscaping eliminate the need and expense of air-condition in our region.

The money you save by not installing an air-conditioner and the energy to run it, you can put into better windows and insulation which also help to conserve heat in the winter.

Humidity

Comfortable humidity levels are generally 30 to 60% relative humidity. This is easy to achieve in our climate. Kittitas Valley is very forgiving to excessive humidity.  The only danger areas are bathrooms or other wet locations that may grow mold and mildew if not ventilated correctly.

General comfort

What is a comfortable environment inside your house? It is not a cold floor, or a cold draft, or smelly cabinets, or sneezing. It is a fairly uniform temperature gradient from floor to ceiling. It is adquate fresh air flushing out the stale air. It is daylight from the windows penetrating deep into the rooms.

Proper and appropriate plans with good construction technique and attention to building details can achieve a very satisfactory level of comfort in your home. After all, isn't this what a home is for?

GB