https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/ Building science knowledge, HVAC design, & fun Tue, 11 Jul 2023 23:36:47 +0000 hourly 1 https://wordpress.org/?v=6.6.2 https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5838 Sun, 15 Sep 2013 16:29:40 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5838 Attempting to make cold air
Attempting to make cold air inside the hottest part of a house is like attempting to break a land speed record with flat tires on the vehicle. 
 
It’s time to stop the insanity and change house design to include mechanicals and air distribution within the thermal boundaries.

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5837 Mon, 17 Jun 2013 20:54:22 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5837 Bob: What?
Bob: What? You don’t want to spend a lot of time in attics in the summer? Yes, you’re right. If HVAC companies are doing the other work, that’s a perfect way to set up the work schedule. 
 
Geoff H.: Yep. There’s a gazillion stories just like that. 
 
Mike M.: You’re one of the few I would trust doing that and making it work. In this attic, the duct coming off of the trunk was only half the length of the longest run. 
 
M.Johnson: I think they typically don’t drain to anywhere. The little black thing you see on the edge of the left side of that pan is a water sensor with a cutoff switch. I did see a really clever idea for draining that pan on another house recently, though. They ran a pipe to the soffit and had it drain right above a window. That way, if the pan fills, someone might have a chance of seeing the water draining outside their window and then call the HVAC company. (I’ll post a photo of it on our Facebook page in a little while.)

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5836 Mon, 17 Jun 2013 20:49:59 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5836 @M. Johnson, the code
@M. Johnson, the code requires either a dedicated drain or a float switch as a minimum in attic installations. It’s not a good idea to rely on a dedicated drain because they are usually flat at best and uphill and clogged with insulation more often. Float switches are the best way to avoid a big problem. At this particular home (which is NOT our installation), the customer had a quote to upgrade both primary and secondary drains. In this business, you can only explain the risks and put the ball in their court, but ultimately the customer will make their own decisions.

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5835 Mon, 17 Jun 2013 19:06:14 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5835 On Case #4, take a close look
On Case #4, take a close look at that metal drain pan. Does that have a drain outlet which goes nowhere? I really want to know what is professional opinion on this — it was like that in my house too.

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5834 Mon, 17 Jun 2013 18:31:31 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5834 When your suppy takeoffs are
When your suppy takeoffs are well designed/thought out, and when you provide supply dampers for all outlets at the plenum for airflow balancing, locating takeoffs at the end of the plenum for those rooms which have longer distances to travel, and higher airflow needs, works beautifully. We do it all the time with excellent results, and without any problems balancing room airflows to Manual J/D targets. Just thought I’d throw that out there as an example perhaps of the “rare cases” you mentioned, and in response to the bold “never, never” statement. If it were me, I’d use the double never for takeoffs located on the top of plenums in unconditioned attics, especially when anywhere near the roof deck (very common practice here- where we can/should be burying our ducts beneath insulation (dry climate)). But that was also the case for yours- effectively coming off the top of the plenum. 🙂  
 
Looks like you guys had a fun day seeing firsthand that systems running with borderline airflow, due to poor distribution design and installation, are on a razors edge of a service call. How much better to provide a system that is commissioned at 60-75% of manufacturer’s maximum total external static pressure and full airflow, so that there is plenty of wiggle room for the occasional filter change slip up? 
 
Realizing that dirty filters are the cause of many problems with AC, we’ve been installing field adjustable differential pressure sensors which we commission on each system to trigger an alert at the thermostat when the filters must be changed. We’ve found this to be much better than the timed reminders because it won’t go away by a simple button reset (requires an actual filter change to restore the proper pressure), and it keeps filters which don’t require changing yet from entering landfills prematurely.

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5833 Mon, 17 Jun 2013 17:44:06 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5833 It is amazing how often the
It is amazing how often the only problem is either a) dirty filter, or b) loose/disconnected ducts. B on almost every home (new or old), and A on large percentage. 
 
I once worked on a home w high bills and poor cooling. I asked if they checked filters and changed them regularly. Answer: “Oh yes, usually every month.” So ed looked. 
 
Syst 1: Filter grill was painted to the wall. Painting was done over 1 year ago. 
 
Syst 2: Owner did not think there was a second air return, but there was another filter grill in the upstairs hall (directly at top of stairs). When I pried the filter out, it looked like the ones in your article. There was a ‘Woosh’ and the Owner asked “what’s that noise?” The answer was the house became significantly more quiet! Once the air started flowing, the earlier roar of the A/C went away. The Owners had simply become used to the very loud background noise and thought it was normal.  
 
Problem solved! Recommend check and replace filters each month.  

]]> https://www.energyvanguard.com/blog/a-day-in-the-life-of-an-air-conditioner-service-professional/#comment-5832 Mon, 17 Jun 2013 15:29:57 +0000 http://energyvanguard.flywheelsites.com/?blog_post=a-day-in-the-life-of-an-air-conditioner-service-professional#comment-5832 A big part of the problem is
A big part of the problem is everything is crammed into the summer months in southern climates, Very little work in the winter, then 8-10 calls per day in summer. Moving home performance work to the cooler times of year when it’s not so hot in the attic and there are less calls to run would help keep everybody working through the winter.

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