Doctor, it hurts when I walk this way, or HVAC Checklist

Patient: Doctor, it hurts when I walk this way...
Doctor: Don't walk this way, then...

Buying a house is a major pain.

What I was talking about, again? Ah, the usual complaints people have about the house they just bought.

• A particular register is too noisy.
• Return air grill is too noisy.
• Air handler is too noisy.
• Condenser is too noisy.
• A particular room is too cold or too hot.
• One floor is hotter than the other.
• A room feels stuffy when the doors are closed.
• A/C can't keep up with the heat.
• Heater can't keep up with the cold.
• Air in the house feels musty.
• There are dust traces outside of registers.
• Bathroom walls stay moist forever.
  

The list becomes pretty long pretty fast, but it can grow significantly longer.

For one single reason: people don't pay attention to HVAC. They think about anything and everything except HVAC. And realize they're in trouble just as the train has just departed.

So, how this can be fixed? And who is in a position to fix it? Unsurprisingly, people who can benefit from this, at the same time helping potential victims avoid being trapped - realtors and, to less extent, HVAC servicemen.

It's a double edged sword, though - for realtors, HVAC is just one more hoop to jump through. For both the buyer's and seller's agents, this is an obstacle on the road between today and the moment they cash the commission check. It would take a person of high integrity to step away from otherwise inevitable financial gain - but wait, we're getting into old good argument about reputation...

Theoretically, it should be a part of home inspection report, but I'm yet to see one that would address those particular issues, or even if it did - somehow a $20 register doesn't seem to register, no pun intended, when a typical house could very well cost north of half a million dollars and this is exactly how much is at stake when you are considering buying it (or so you think at the moment. Actually, the stakes are even higher - your well being is at stake). Especially keeping in mind the fact that issues like this will surface well into the process, after you have already decided to make an offer, paid inspection fees and generally are tied up pretty fast.

Another issue is that a person or a crew that will perform the inspection is not necessarily highly proficient in HVAC. Yes, they know the motions (check the supply air temperature, etc.) - but what they do may not be enough. Then again, it is applicable to every possible subsystem in the house (Gawd! Don't ask me about the state the wiring system was in at the house I live in...) So the advice here would be to actually make an extra step and pay a HVAC contractor (yes, and the plumber, and the electrician, and the roofer - the list goes on and on). I don't think you would regret this much, especially in today's market - you may be ecstatic and think you've just coaxed the poor desperate seller and made a steal, but tomorrow will come and you will see that you're already upside down with all the problems you've overlooked.

But let's take a step back and read the complaints above. All of them share one property: they are obvious. All you need to do is pay attention.

There are certain things you can do in order to make those those problems more obvious.

• The most difficult - look for a new house during most unfavorable season. I know, it is difficult, and plans may not work this way, and it would be difficult to have extreme conditions for the heater in the middle of the summer, but at least try. According to 6 years of observations, for Arizona (actually, North Valley, but it may be good enough for all of South Arizona) the coldest period appears to be a second half of January, extending into first half of February. Hottest period is usually the second half of July - immediately followed by the humid period (one thing I can say, though, is that if you have humidity problems in Arizona, out of all places, you'd better start walking away from that house before you finish reading this article).
  
• Next best approximation is to schedule a visit during most unfavorable time of day. Hottest time of day, as far as cooling is concerned is around 5PM. Don't even hope to get the coldest time of day - unless you get to spend the night at the house, which, in this favorable to buyer market, may not be impossible.
  
• Spend as much time at the house as you possibly can.
• Make sure the doors stay closed during this time.
• Open the curtains, don't take no for an answer.
• Shut off the fans. Even if you like them and want them. Fans may mask the problem that already exists.
  
• See where the thermostat setpoint is. Don't be cheap and spend $20-30 at RadioShack to buy a decent digital thermometer, say, 63-1087 or 63-1088 (disclaimer: I haven't tried those. The one I have is 63-1032, but it is wired).
  
• Listen to the HVAC noise.
• Run the hot shower for 15 minutes and see what happens to the walls afterwards. Hygrometer would probably be useless - sensor has too much inertia.
  
• If you feel particularly adventurous, you may even want to shut off the HVAC for a while and then switch it back on and see how it behaves. Keep in mind, though, that if it brings the temperature back no normal within 15-20 minutes, you have a unit that is actually oversized (unless it is multistage, which is very rare).
  

And, again, start paying attention.