Quote:
Originally Posted by AC_Hacker
Really depends on how many hours a day you intend to run it.
If you do a break-even analysis, considering the initial cost (fixed cost), and the incremental cost (variable cost) of running in your comparison you will see what's going on.
I tend to strongly prefer units with the highest HSPF (for heating) because of cost, and also I am aware of the CO2 advantage. despite higher initial cost.
However, I was doing the very same consideration for a unit to use in my basement shop space, and in that case, the higher HSPF did not pay off.
The reason was that my shop heating is so intermittent, that the efficiency advantage was never there, even projecting a 15 year life.
I did the same comparison against a resistance heater, and the lower efficiency heat pump was the winner, even with intermittent use. Breaking even in about a year and a half.
-AC |
Since we are using it to cool off the bed room during the day, all day its going to see a lot of hours.
If I were going to put one in my garage, where it might get used 1 or 2 days a week max, yeah I would go with a cheap big one for sure.
To determine the power use I had to assume the 6,000btu window unit was going to run about 5 amps of 120v power pretty much from about 10am to 5 or 6pm with the bed room door shut and it couldn't even cool off the room during the hottest part of the day.
If I close the door to the bed room the new split unit will cool the room down and draw down to around 1 amp of 240v power or less. So its using pretty close to half the power of the window unit. Usually just leave the door wide open so it can cool the living room too, as opposed to turning on another air conditioner.
So if I left the door closed it would use about half the power during the day.
Also I just got finished putting new double pane windows and I am going to insulate the walls soon. The walls have northing in them, aside from a layer of black fiber board that as far as I can tell has an insulating value of about R-1. Which I guess is slightly better than nothing. I am going to hand fill them with cellulose.
And lastly I am going to resell the window units on fb to pay for part of all this.