Heating and air conditioning contractors, like the rest of us, make mistakes. They make mistakes that hurt performance and efficiency of the HVAC systems they install and maintain. Their mistakes can hurt their customers sometimes. Their mistakes hurt their businesses too. Here are 7 of the biggest mistakes that we see around metro Atlanta.
1. Not understanding combustion safety
When some HVAC contractor responds to a carbon monoxide alarm going off, they'll usually go straight to the furnace and look for cracks in the heat exchanger. When they find that it's OK, they often assume it must have just been a false alarm, so they change the batteries in the CO alarm. The problem is that other HVAC contractors don't know much about backdrafting of combustion appliances. Nor do they test for it. If your HVAC contractor is not testing for flue gases and worst-case depressurization, they're leaving a potentially dangerous situation. You never want to find out the next day that the people in the house you just visited are in the hospital with CO poisoning.
2. Focusing on 'the box' and ignoring air flow
If the vast majority of HVAC contractors did professional quality work, we wouldn't go into house after house after house and find the same kind of duct problems. If other Atlanta HVAC contractors understood air flow, most duct systems would be larger than they are.
3. Ignoring the opportunities in home performance
In the metro Atlanta market, HVAC contractors go into people's homes every single day. They go into attics, crawl spaces, and basements, where they can see the quality of the insulation and air sealing in the home's building enclosure. Even if the HVAC contractor doesn't do the insulation and air-sealing work like we do, they should advise the homeowners on the other work their home could use to improve its overall performance.
4. Forgetting the V in HVAC
V is for ventilation. The insulting way to state this is that any HVAC contractor who doesn't address the V in HVAC is just a HAC (read: hack). Energy codes now require a higher levels of air-sealing. Air tight homes need mechanical ventilation. All homes need spot ventilation in kitchens and bathrooms. If you aren't getting good ventilation, then the other contractor doesn't understand the 3 strategies for providing mechanical ventilation (positive pressure, negative pressure, and balanced). Have they measured the air flow in your ventilation systems?
5. Skipping the math
HVAC contractors like rules of thumb. They also rely on what they think worked in the past. Well, guess what. Heating and cooling systems aren't the same as they were 50 years ago. Nor are homes. Rules of thumb don't work because every house is different. If you want to size a system properly, you've got to come up with some way of getting at the rate of heat loss and heat gain in the home you're working on.
So there you have it. That's the top five. Hopefully if you're using someone other than Assured Comfort, they aren't falling into any of these traps or through anyone's ceiling.