As for the home warranty thing, we needed a new air conditioning unit a year after we moved into our house and figure it would have cost about $10K if we’d had to pay for it ourselves (my in-laws had to do a similar installation at around the same time and that was their out of pocket cost). So it can be worth it, but it probably depends a lot on the condition of the house (we knew when we moved in that air conditioner would need to be replaced soon, we just didn’t realize how soon).

It isn’t really a matter of the compressor running more due to lack of refrigerant, it is more a matter of improper lubrication due to poor oil return, improper pressures, and potentially contaminants getting into the system.

I wouldn’t worry about the 10 seer/13 seer argument. You can mix and match parts of differing efficiency without total doom and gloom. Sure it may not be as efficient as it could be, but it will cool.

Don’t bother with a home warranty. They will first attempt to deny the repairs, then they will send out a bottom of the barrel contractor to make the repair, who will invariably repair it the cheapest way possible.

INSIST!!! on a Manual-J heat loss/gain analysis from your HVAC contractor. If he cannot/will not supply one, find one who will. Long gone are the days of guessing whether a particular system will be up to the task of heating or cooling a particular space. A heat loss/gain analysis should take about 30 minutes to complete and takes all of the guesswork out of sizing equipment. The vast majority of HVAC equipment out there is oversized, and I’ll bet your current system is as well. I may be able to run one for you if you want to contact me off-line. But like I said, a good HVAC contractor should run one for you.

I don’t think you’ll ever see a return on the money spent upgrading just for the sake of efficiency ($7000 buys A LOT of cooling). But one problem that you may run into into is this:

Last year the government mandate for A/C efficiency went from 10SEER to 13SEER. If your old compressor is 10SEER, you will probably not be able to buy an A-Coil that is 10SEER. A 13SEER A-Coil will not work with a 10SEER compressor.

Good luck…

I could afford to replace/repair my 2007-model car, but I prefer to pay insurance just in case (for full coverage). I could afford to pay for the birth of my son last year – even with unexpected complications I had that brought the total to 7x what we’d planned – but I’m happy our insurance foot the bill.

Usually, health insurance is a losing proposition for us, 2006 being the exception. Car insurance has always been a losing proposition – until I rolled my truck in 2005 to the tune of $11k.

It’s these once-in-a-lifetime (hopefully) expenses that make up for the “losing” in previous years. That’s why most people still carry these types of insurance. I look at the home warranty in a similar fashion. The big hit might not come this year, and may instead be next year. I’m glad I”m covered, whenever it comes.

Of course, it’s an individual decision, and our having a home warranty is based on the shoddy construction of our home and our own lack of technical know-how were we to need to fix anything ourselves. Those are clearly two factors that make our situation unique.

But to say that it’s a losing proposition and therefore not worth it kind of negates most other insurances.

On average, we lose on insurance in general – otherwise the insurance companies wouldn’t be in business.

Now, I won’t buy the “extended warranty” on electronics I’m offered at checkout. I’m no sucker.

Given that we can afford to repair (or even replace) our heat and air, and given that warranties are (on average) a money-losing proposition, I’m not going to pay someone else a premium to bear the risk.

Sure, we might’ve come out ahead had we bought a warranty (in this case) but, on average, we’ll lose out. Given this, I don’t think it’s the right move for us, though I can understand why people might purchase this sort of warranty.

Even if we were using our HELOC (we have one, we just don’t ever tap it) I don’t see how that would (or should) factor into whether or not it’s a good idea to replace our system.

Just because someone *can* borrow money for something doesn’t necessarily make it a good idea.

But good point on the tax credit. That would save us a bit.

An A/C unit is completely different but I remember when it was extremely hot out around me, it was too hard to focus, let alone relax. Good luck with the repairs!

As it stands, I’d probably upgrade (and get a home warranty).

I replaced everything. (After waiting one year. We have mild winters.) And I may have made the wrong decision. I have seen no difference in my electric bill with my new super-efficient unit.

So that’s my bias. I recommend you get someone unbiased, like maybe the kind of inspector people get when they’re about to buy a house, and ask what they think about this quandary. Is the coil the main thing that breaks and once you replace it, it’s all smooth sailing? Or is this a sign that one by one things will be falling apart now?

Also, I kind of like the idea of two systems. Then if one breaks, you can live in the other part of the house while you’re saving to fix it.

Here’s another idea. Repair the unit. If it turns out not to be big enough, get window units and use them until your big unit breaks again. I mean $1,000 versus $8,000? That’s a huge difference. Window units are not cheap to run, but you might have to run them only occasionally depending how much you use the far away parts of the house.

The pro about waiting though is that you will get to live in your space and get a feel for if it is enough air flow or not.

Get some prices on off brand units (Ducane made by Carrier is my favorite) you could save a fortune on the units. As far as energy efficiency, you’ll never recover the added cost of high tech units (sort of like buying a Prius) On top of that the two-stage units are maintenance pigs, so you’ll need a guy named Gunter to fix it; he’ll want $200/hour plus expensive parts.

Consider the KISS method and like everything else, shop around and compare prices.

Oh, and it’s not totally about the square footage. There are some detailed heat loss calculations that go into it. We were on the cusp of a 4 or 5 ton system with our 2300 square feet due to the number and type of windows in the house.

Also, shop around for the best deal; and if you don’t already have a service agreement, consider getting one. Our heating / cooling company offers a 15% discount on parts and labor with a service agreement; in addition to expedited service calls, and the waiver of the ‘emergency’ call fee should a repair be needed after-hours, weekends, or holidays.

Finally, see if there is a manufacturer’s rebate on your model; like cars, heating / AC dealers sometimes want to clean out excess inventory or last year’s models.