For anyone who spends a little time in Texas heat, you find quite quickly that air conditioning is a very serious topic here. So messing about with a home’s working AC equipment as I have done is, generally speaking, looked upon as crazy. There’s talk of interrupting circulation and “overworking” things, plus every other type of armchair quarterbacking imaginable. However, I did it anyway and wound up with some interesting results.
My home is one story and a touch over 2,000 square feet. In the summer months it’s not difficult to keep cool, but it is expensive — almost triple what the spring/winter months cost, to be exact. So AC is the real trick.
While watching the Travel Channel visit exotic places I will never go, I spied an idea. In an exclusive Italian town I saw a villa equipped with a smart AC system to cool only the bedrooms the residents were sleeping in during the night instead of the whole house. That gave me an idea.
I only use two bedrooms in my house at night. I can’t afford the uber-smart central air with its temp sensors and computer controlled flow; this was a fact. But why couldn’t I mount two window units in those rooms and set the central air for the entire house to 78 or 80 at night, then use much smaller, say 6,500 and 5,000 BTU units to make up the difference in those bedrooms? As it turns out, I can.
The larger of the two units was a Frigidaire LRA074AT7 window unit with a 6,500 BTU capacity. It has all the modern bells and whistles like auto mode, which makes it run just like your normal central air system by sensing room temperature, and of course a remote. I also picked up a smaller 5,000 BTU unit from the same manufacturer that had all the same features except for the remote. They ran $150 and $99 respectively. Each was rated for the room size of the spaces they were set to cool and installed in a window of that room with the door closed during the night.
So armed with last months electric bill and the bill from the previous year in the month I was going to test, I carried out the plan. It turns out when all bills were totaled up, April this year cost me $176 and May was $129. So it was already less than the cooler month before it. Looking at last year’s May bill suggested more savings at $211 vs. the new $129. So anywhere from $50 to $80 a month in early summer months. A good start.
Is this a sure thing? No, of course not. However, should this continue to work going against last year’s numbers I will have at least broken even by August, and that’s worth something right there. More data and further unscientific testing needs to be done on my part. Plus figuring up kilowatt/Hours per unit, hours run and the like would help as well.
That said, this little experiment does assist with several areas that I can already see helping in the long term. The first is it saves wear and tear on the large central AC unit that is on less during the night. The other is that we now have backups in case the central unit does go out completely, which can be very ugly down here where triple digits are commonplace.
More on this experiment as developments occur.