Hi Lawrence,
So far the Espar heater I purchased for my Sprinter is working great. I chose the Airtronic 4 model which seemed right for either a Sprinter or a large truck sleeper. The Airtronic 2 model would suffice in a GMC,Chevrolet, or Ford van.
The Airtronic 4 cost me $1600 out the door installed. I belive the Airtronic 2 would have been $1250.
The lowest temperature I ran into so far is 25 degrees and the Espar unit ran most the time at the medium setting, keeping it nice and toasty inside.
There are 4 sttings that are automatically chosen by the thermostat. Low is 3,400 btu, med. is 6,800 btu high is 10,200 btu, and boost is 13,600 btu. Fuel consumption is .03gal/hr. in low,.07gal/hr. in med.,.1gal/hr in high, and .13gal/hr. in boost. Battery drain is .6 amps.in low, 1.1 amps in med., 2 amps in high, and 3.3 amps in boost.
If you idle a truck, for purposes of producing heat, 8 hours a day, for 5 days a week, over a 30 week period each year you would use 1,200 gals of fuel. That is assuming an average consumption of 1 gal/hr. At a price of $1.40 per gal. it would cost $1680 to heat your truck for just one winter.
Using the Espar Airtronic 4 heater for the same amount of time you would use 84 gals. at a cost of $117.60 at the medium setting or if you perfer to sleep in tropical conditions you would use 120 gals. at a cost of $168 with the setting always on high.
I will leave you to figure out what the additional savings would be in the wear and tear category.
Obviously, the savings benefits of using the Espar heater over idling an engine for heat, would be enough to pay for the Espar heater in just one season's use.
I will let you know how well the Espar heater works in extreme temperatures later this season.
To answer your question as to where I heard about the Espar Heaters it was on a great site on the web,
www.expeditersonline.com.
Just click on Open Forum and go to search.