It’s hot in the house.
Today, I should be getting a quote to install a new AC system. My old AC system is probably 15 years old, judging by some documentation I was able to find on it. It has finally reached its end-of-life.
The AC unit has always been a little finicky. For as long as I can remember, there were occasions where the compressor outside would just shut off and the blower inside would keep running. Soon, it would be blowing nothing but hot air. The fix for this was to pull the thermostat off the wall and put it back on after a few seconds. Seriously. It was like pulling the battery of your non-responsive cell phone, except it is your house. Oddly, flipping the circuit breaker switches wouldn’t even resolve it.
I’ve had techs come out more and more frequently to fix things. Over time, it’s been a bad solenoid, a failed blower motor, a bad thermostat, a failed cooling fan, and a clogged air filter (duh, me). This time I brought them out and the diagnosis was grim. The compressor outside was not performing up to par. There’s not really a way to fix that, so it has to be replaced. The tech said the compressor was only drawing 6 amps of power when it should be drawing around 15. Conversely, when the compressor starts up, it spikes the power, at about 52 amps. My suspicion is that it is requiring a large boost of power to break out of its inertia. Regardless of the reason, 52 amps is pretty close to my circuit breaker’s limit of 60 amps. So, if it fails much further, it’s just going to start tripping the circuit breaker and then it will just never start up again.
I asked the tech what brands they sell and the response was ComfortMaker. I’d never heard of the brand before and I thought it was a pretty dumb name, very generic sounding. Internet research shows that ComfortMaker is a known brand and is a sub-brand (more or less) of Carrier, which is a very well-known brand. One of the other interesting bits of knowledge I picked up is that “they don’t make them like they used to.” That’s hardly news, but there’s actually a reason for it. My unit, as old as it is, is built like a tank. But that build quality comes at a cost. Just like automobiles, the older cars were built like tanks, but they were inefficient. They would last forever because of their heavyweight components, but would cost a lot of money doing so. Newer AC units are highly efficient, but they gain that efficiency by using thinner copper pipes and lighter materials. These parts wear out quicker, but they save you money while they’re running. So I guess the take-away is to bank whatever you save from a new system for your next system. The march of progress.
I’ve also been researching a bit about tonnage and SEER and heat pumps. A Q&D calculation says I should have a 2.5 ton compressor. I currently have a 4 ton compressor and a 5 ton air handler. Why’s that? Well, the old knowledge was: bigger is better. Plus, the house used to have a converted garage as a game room, so a bigger unit was needed anyway. Old knowledge was that you could gain efficiency by having a larger air handler than your compressor. Also, they thought that if your compressor runs less, you’re saving money. But all that advice is gone now. The new knowledge is just size the unit correctly. You shouldn’t have your compressor cycling frequently because of the wear on the unit and the large power draw when it starts up. It’s better to have it run constantly when it’s hot (which mine is doing now, although that’s not a good thing in my case).
So today, I am waiting on the proposal to do the work. A co-worker coincidently also was having AC trouble and while he got his system stumbling again, he chose to schedule a replacement. His quote was $8k. Ouch. That’s a bit over my maximum budget. One difference is that he’s going to have an extra return duct installed with the new system. Mine should hopefully just be a simple swap-out.
My budget for this is: $3k, no-brainer; $5k, soft maximum; $7k, hard maximum. I was told there is about a 1 week lead time on scheduling an install, so I’m going to have to get used to 80 degree indoor temps for a while. Unfortunately, this pushes back my plans to install a garage door. But, this was a known upcoming expense. That and a new roof. With the pool already redone, once the AC and roof are redone, the house will be brought back to current specs and should be good for another decade or so.