Which Espar Heater?

I have a TriPac that came with an Espar D2. I'm getting ready to have them installed. I am thinking about upgrading the Espar. At first I want to upgrade to the D4, it puts out a little more heat which would be nice when I am in Alaska. Realistically, I don't go to Alaska that much. I spend most of my time in Texas. We have a few cold days below 25 F., but rarely. For instance, the last week or so, we've had lows in the 60's F. The D4 is overkill, but so what, it would be perfect for those -40 F. days and nights, and wouldn't have to work so hard in Texas. Then I learned of the Hydronic 5, the unit that heats your coolant which warms you engine. Is this unit suitable when used to warm the cab and sleeper? In other words, can it be used as a cab/sleep heater all night? Even when warming the engine isn't critical? Doesn't the TriPac have the option of having a coolant heater? Is this the coolant heater that comes with the TriPac upgrade?

 

Doesn't the Extreme Arctic Package come with the Espar Airtronic D4? I'm wondering if it doesn't come with one of the Espar Hydronic units. I don't understand completely how the TriPac works and what all comes with the Extreme Arctic Package other than the D4 (I think) and the larger alternator. I can use the D2 for my F-350.

 

I wasn't aware of a D3 unit, it is not listed on Espar's website.

 

[TABLE]
[TR]
[TD="width: 30%, bgcolor: #ffd76e"]Specifications
[/TD]
[TD="width: 30%, bgcolor: #ffd76e"]AIRTRONIC® D2
[/TD]
[TD="width: 30%, bgcolor: #ffd76e"]AIRTRONIC® D4
[/TD]
[/TR]
[TR]
[TD="width: 30%, bgcolor: #ffd76e"][SIZE=-1]Heat Output
BTU/hr (KW)[/SIZE][/TD]
[TD="width: 30%, bgcolor: #ffd76e"][SIZE=-1]7,500 (2.2) Boost
6,150 (1.8) High
4,100 (1.2) Medium
2,900 (0.85) Low[/SIZE][/TD]
[TD="width: 30%, bgcolor: #ffd76e"][SIZE=-1]13,650 (4.0) Boost
10,200 (3.0) High
6,800 (2.0) Medium
3,400 (1.0) Low [/SIZE][/TD]
[/TR]
[/TABLE]

 

For some reason I can't do certain things, like add paragraphs on this forum. Anyway, the chart above shows that the D4 at it's lowest setting should be comfortable. Any yes, insulating my truck is on my list of things to do. This is a list that is getting longer and longer by the day. I plan on keeping this truck for the rest of my driving career, so I might as well drop money into it.