3 ms·
A SEER 13-14 system can run $5-6K, while a SEER 22 system can cost upwards of $15K (as a guesstimate). In theory, a SEER 22 system can pay for itself over the l
by mjfern 9y ago
A SEER 13-14 system can run $5-6K, while a SEER 22 system can cost upwards of $15K (as a guesstimate). In theory, a SEER 22 system can pay for itself over the long-term due to reduced electric/gas expenses. The issue is that higher SEER systems, above 16 I believe, rely on variable speed motors. My understanding is that they are inherently less reliable.
A SEER 13-16 system might last 15-20 years (if you're lucky), while a SEER 22 system could break down much earlier at about the 10 year mark. You can sometimes replace specific parts, but depending on what breaks, it may not be cost effective.
In short, the only way we're moving to more efficient AC systems is if costs come down significantly, we see some major innovation in the field, or the government provides significant financial incentives.
As an aside, I also think we could achieve energy efficiencies by increasing the insulation in houses. It's unbelievable how much hot/cool air is lost through windows, doors, crawl spaces, and attics.
- EvanAnderson 9y agoI've had some major frustrations with poor reliability of the blower motor in a 14 SEER HVAC system (installed in 2006) with a brushless DC motor. I've replaced the motor 3 times in 10 years (conveniently failing shortly after the warranty expired each time). Had I not done the work myself that would have been between $600 and $800 per replacement. Brushless / electronically commutated DC motors are pretty interesting, though: https://en.wikipedia.org/wiki/Brushless_DC_electric_motor https://en.wikipedia.org/wiki/Brushless_DC_electric_motor
- mjfern 9y agoWho's the manufacturer?
- EvanAnderson 9y agoThe air handler is a Bryant. The motors have been a General Electric X13 (the original patent-holder for the X13 electronically commutated constant-torque PWM motor controller), a Regal Beloit "Evergreen" X13 OEM replacement, and now a Nidec X13 motor. These motors are microcontroller-based. Apparently there was a rash of bad GE X13 motors in the early 2000's traced to bad thermistors. Unfortunately the board is potted in an insulating compound that makes board-level repair rather impractical. My first motor's controller failed after about 8 years. It was cheaper to just buy a new motor vs. replacing only the controller. The second motor's rotor started grinding against the stator after about 13 months. I pulled the controller from that motor and installed it on the first motor (since it was near-perfect duplicate of the original motor). That ran for 14 months before the second controller failed. I've been running the third (Nidec) motor for about 2 months. I'll be interested to see how to holds up long-term.
- deleted 9y ago[deleted]
- rplst8 9y agoI've said elsewhere in the thread, but insulation does little to help in the summer months. Fiberglass insulation mostly protects from convective cooling/heating (i.e. airflow). Heat in the summer is mostly through conduction and even more-so radiative (near infrared). Windows treatments could definitely help there, but unless you want everyone's windows to be mirrors, it likely won't help that much.
- amluto 9y agoLow-emissivity low-solar-heat-gain windows are a thing. I think they're not even particularly expensive compared to any other window.
- coredog64 9y agoWe just replaced our AC system, and while SEER 22 would have saved on electricity, it would have required several thousand dollars more in new duct work. The high efficiency systems require not only variable speed air moving capability, but ducts that work with it as well. We went from SEER 10 to SEER 15. With the rebalancing that the contractor did, our house is much more comfortable with the thermostat at 80 than it was under the old system at 73.
- cestith 9y agoUnless it raises the resale value of the home reliably, long-term payback is of little motivational value without job security or significant money in reserve. That's one of the uncomfortable microeconomic truths driving short-term decision making in things like cooling, solar power, and battery systems. Why would someone take out a loan or tie up a large portion of their liquid capital to see a ten-year payback on a house they might be forced to sell next month? With 2008 not being so long ago, neither job security nor resale value are that promising. We're still rebuilding consumer confidence after nine years. The economic recovery in the US is largely in a handful of major metropolitan areas pulling up the averages, with large swathes of the country still struggling. This needs to improve or some government incentive program like you mention must take it into account if we're going to sell capital-intensive home upgrades.
- cestith 9y agoHey, this is HN. I'd love to discuss how I'm wrong or have someone provide links to refute anything I've said rather than random downvotes for posting something with unpleasant ramifications.