Solar Window Heater BTU

I wanted to point out some differences between our solar window heater and a typical electric space heater.  The electric space heater is great if you have a bottomless bank account to pay the electric bill.  If you ran a 1500 watt space heater 24 hours a day for a month it would use up 1070kwh. If you run our solar window box heater then you have to pay for the fan at 3 watts an hour for five hours a day for a month and it would use up a whopping .45kwh.

Most heating systems are measured and sold with a BTU/h rating.  That means British Thermal Units / per hour if you were wondering.  BTU/h is the energy it takes to raise one pound of water one degree Fahrenheit.  Or one blue tipped wooden match is equal to one BTU.

With that being said we can compare BTU/h of the electric space heater and our solar window heater.  I picked at random a typical electric space heater you might find at your mega WEGOTITALL store.  The model I picked uses 5118 BTU/h while sucking the life blood out of your electrical outlet and checking account at 1500 watts.  Now lets look at the formula for calculating BTU/h to see what a 2ft x 2ft solar window heater is doing.

 H = 1.08 q (t₂ - t₁) η        

H = heat transferred (Btu/h)
q = quantity of airflow (cfm)
1.08 = a constant for sensible heat equations
t₁ = air temperature of the exhaust air before the heat recovery unit (^oF)
t₂ = air temperature of outside air after the heat recovery unit (^oF)
η = heat-recover efficiency

For our solar window box  we can input the following:
 q= 77 cfm
t1= 68 F
t2= 125 F
N= 1.00 for 100 % efficiency because we are using no fuel to create the heat.

Thus the answer to what the BTU/h is 4640.10 for our solar window heater.  Pretty damn good for being powered by just the sun.  I'm loving my 6th grade algebra teacher right now.

One or two obvious points to make.  The electric space heater is portable and will work 24 hours a day as long as it has an outlet to plug into.  Our solar window heater only works during peak clear sky solar hours.  All of our systems are a supplement to your existing heating system.  When our solar window heater is working it is practically for free where you only pay for the power to run a 3 watt fan.  We have our prototype in the window of the living room/dining/ kitchen which is about 300 sq ft and it keeps pumping out the free heat.  Even if it keeps the furnace from turning on a few times a day that is a huge savings to our energy bill during the winter.

Talk to ya soon!
Mat

I am having a blast marketing our 2ftx2ft solar heater window boxes.  I've been posting links on Google + and doing some advertising on a low budget to see how it works out.  I posted this video yesterday on YouTube.  Feel free to put a like on the video on YouTube and find us on facebook at Sun System Designs and put a like on that site too.  Spread the word and put renewable energy one step closer to ending global warming. 

100% free heat from the sun during the winter can not be beat.  Check us out at sunsystemdesigns.com and feel free to drop us an email.

Talk to ya soon,
Mat

How Solar Heating Works

Have you ever stood or sat in a window in the middle of winter and just taken in the sun and enjoyed its warmth?  What if you could bottle that heat or make it heat the entire room you are sitting in?  What if you could put a simple two foot by three or four foot box in the window that would heat the air upwards of 120F inside of it and push that solar heated air out into your room during peak sunlight exposure?  If the sun is shining for a couple of hours could you then have free heat during that time.  It can be done.  It is being done in my little apartment.


I have been working on that idea for several years.  Trying one idea and tossing it out, trying another idea and tossing that out, and the ideas kept getting better.  Trial and error is the only way to make the best solar window heater there is.  And that is what I have been doing.  I've built tens of different box designs and each one did just a little better than the previous one.  Researching materials along the way to find the best heat gain materials that outperform all others.  Researching specialty coatings that capture most of the specific spectrum of sunlight that provides heat.  Researching airflow systems to move the heat from inside the box to inside your home with the utmost efficiency.

I have been exploring and testing solar heating for several years now and it is amazing how solar heating performs.  Anyone can throw in a bunch of metal into a box and seal it up and get free heat from the sun but the ability to make it actually work takes time to understand and perfect.  I found the best way to make the airflow and heat gain balance out so that you get consistent heat when the sun is shining.  And all you have to do is put the box in the window inside of your home.  Plug in the controllable fan and you have free heat as soon as the box heats up during peak solar times.  Free heat from the sun.  I should mention that I am also working on systems that you don't need to even plug in.  Self contained free heat from just the power of the sun and a mini solar panel.

How the solar heater boxes work is a combination of metals, specialty coatings, heat retention systems to hold the heat on partly cloudy days and the processing of the heat with a temperature controlled fan system.  Some people will argue that you get the same heat benefit with just the sun shining through the window but that ignores the facts of solar heating.  Solar heating concentrates the suns rays on the materials inside the box raising the temperature far beyond any solar heat gain by hitting the floor or other materials in a room.  It captures that heat and heats the air inside the chambers of the box which then turns on a programmable fan that forces the heated air out of the box.  Changing over a 10 x 12 rooms air several times per hour at the heated air temperature.

Feel free to comment or check us out in the video below with one of our first prototypes.  You can check out our website at SunSystemDesigns.com or find us on facebook under Sun System Designs and please put a LIKE on our page.  We look forward to hearing from you and your continued interest in solar heating with just he power of the sun.  Below is our video on YouTube on one of our prototypes in action.  Check it out and spread the word to friends and family.