Hi, We have been using your page for school and we like your links. :-) Thank you for letting us use them. We had the awesome idea that we should send you suggestions of other ones that we like to use as a thank you. Our teacher Mrs M thinks its very thoughtful of us and that you could maybe put them up on your page with the other ones. Thats why we are writing to you. The ones we like are http://www.aaenvironment.com/environment-library-endangered-animals.htm http://www.portal.state.pa.us/portal/server.pt/community/just_for_kids/13936 http://www.thewaterpage.com/water-conservation-kids.htm http://www.plu.edu/sustainability/How-can-I-be-involved/Great-Ways-to-go-Green-at-PLU/home.php Do you like them too? Please write back. :-) Mrs M's Class Hi, I am A. M. Happy Early Earth Day! The letter above is from my 5th grade class. As they mentioned, we have been using your page as a reference for our projects. I hope you don't think that we are out of line in contacting you, but I know it would really make their day if you could add some or all :-) of their suggestions to your list. They really like to share! They couldn't wait to write to you and we had to stop in the middle of our lesson to write this email. I am even considering giving them extra credit if you decide to add their suggestions. Anyway, please write back as soon at it is convenient for you to do so and let us know. I really appreciate that you took the time to read our email. Thank you so much.
Mrs. A. M. and Students
Good Afternoon Ms. M and Students.
I first want to thank you for visiting our website and providing suggestions to make it better. There is a team of people that work hard constantly evaluating, updating and figuring out how to improve the site. I am copying all the members of the website team on this response. We meet in the middle of each month to determine what changes will be made in the upcoming weeks. I trust they will look at these recommendations in preparation of the next meeting.
I am sure that we will be able to use some of them. Stay tuned…
And thanks again
Why does 70° in the winter feels cooler than 70° does in the summer? TW
It is a seemingly simple question, but has a very complicated answer. Human beings respond to their surrounding very different to each other. It depends on temperature, humidity, outdoor climate and region. Some studies have even demonstrated differences based on gender, race, physiology, and economic status in laboratory scenarios. To answer your question I am gong to focus just on temperature and humidity. I believe they have the most significant impact on people here in the northeast.
In this area of the country, we generally have a very dry climate in the winter. Dry meaning low relative humidity. Humidity is defined as the amount of water vapor in the air. In everyday usage we refer to relative humidity (RH), which is expressed as a percent in weather forecasts. This is really a ratio measuring the current humidity relative to the maximum amount which would be 100%. 100% RH is rarely achieved, but high RH outside would most likely mean there was some type of precipitation underway. Humidity can be used to determine the likelihood of precipitation, such as dew or fog. We also use it to calculate climate conditions within an interior space; high relative humidity reduces the effectiveness of sweating in cooling the body by reducing the evaporation of moisture from the skin. Conversely low RH dries your skin more quickly and causes you to feel cooler.
The ideal climate or conditions for humans is referred to as thermal comfort or the comfort zone. Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC (heating, ventilation, and air conditioning) design engineers.
Thermal comfort is affected by heat conduction, convection, radiation, and evaporative heat loss. Thermal comfort is maintained when the heat generated by human metabolism is allowed to dissipate, thus maintaining thermal equilibrium with the surroundings. It has been long recognized that the sensation of feeling hot or cold is not just dependent on air temperature alone. The actual comfort zone is found between 35% RH at 70 Degrees F in the winter and 50% RH at 76 Degrees F in the summer.
Living in New England in the winter the outside air is very dry, roughly 10 to 15% RH. That air is pumped into the schools and other public buildings to provide ventilation. This dry air even migrates into your home. So the dry air creates a cooler feeling at 70 Degrees. In special manufacturing environments and in some homes, moisture is added to the air via a humidifier. That effort will raise the RH and improve the comfort of the occupants. However, office space, public buildings and schools do not have humidifiers, nor is there a requirement to have any. It is also very costly. So to stay comfortable in the winter expose the least amount of skin possible. Dress in layers and when at home use a humidifier and proper humidistat to monitor the conditions. This will help combat the affects of cold dry air went you are away from home.
So with that being said, let’s answer your question. If you are in a room with 70 Degrees F. and 50% RH, you would be more comfortable than in the same space at 15% RH. Dryer the air the faster your perspiration will evaporate and cool your skin and body. So you “feel” that the space is colder, even though the sensible temperature (temperature without the measure of moisture in the air – 70 degrees) is the same.