HVAC inspection routine

[tnpappas]

What is your normal routine for inspecting a HVAC system? Do you stick to the SOP, or are there checks that you conduct that go above and beyond?

[tnpappas]

Everybody, please slow down with those responses! Just kidding.

Maybe, I just need to expand the question a bit. Do you inspect the outside unit on your initial pass or two of the exterior? Do you adjust the thermostat when you initially enter the house to get the system fired up for a period of time before you get to the unit? Heat first, cooling second season permitting? Do you check the systems at a certain stage of your inspection, or when you come to the unit during your inspection of the house? Do you have a certain checklist of items that you make sure is covered in every report. If you find no recent evidence of a HVAC maintenance checkup do you always recommend a HVAC consultation? How many of you measure temp. drops? Take amp ratings? Or remove registers to look around?

I know every system is different. Just want to develop a solid fundamental approach to inspecting in a consistent manner. Also, I understand that everybody has their own ways of doing things. I figure if I can take a little bit of good advice from a lot of different and experienced people, I am on my way to a developing a sound and consistent procedure.

[Jim Katen]

What is your normal routine for inspecting a HVAC system? Do you stick to the SOP, or are there checks that you conduct that go above and beyond?

Troy N. Pappas

"Thanks for all the advice, your training is invaluable."

Kind of like asking, "How do you build a building?"

What kind of HVAC system?

- Jim Katen, Oregon

[Chris Bernhardt]

My basic protocol is to visually observe say a gas furnace and take pictures of it before I touch it. I'll pull the covers and again visually observe it and take pictures before I touch it further. After I am satisfied that it appears safe to turn on, I'll go turn the thermostat on. I usually turn it up high, cause I want to be sure it stays on and not reach temp before I'm ready in case I get off onto something else for a moment. I also want to determine if it's short cycling. After I am satisfied it's not short cycling or not kicking off for some other reason, I'll turn the thermostat down and observe where it kicks off.

If it's the summer time I'll start with the A/C.

I see mostly gas furnaces, followed by electric systems (heat pumps, baseboards, Cadet heaters), then oil furnaces and then rarely boilers.

If the furnace is dusty, I usually automatically write it up for cleaning and service. I look for the filters, identify their location and whether they need cleaning or replacing or just installing. I look for and at the automatic safety controls to make sure they haven't been bypassed. I try to figure out how old the furnace is and whether it's past or close to it's expected service and report on that. I observe how the furnace operates, startup, flames, shutsdown, etc. I look for code violations, and make sure there are adequate combustion air sources means, and observe for venting problems and contraventions.

In my area I see a lot of the same brands and have gotten familiar over the years how they should be operating.

There are so many things to look at and consider, but they are pretty much contained in one area, so it goes pretty quick.

Some guys will check for CO, but you'll almost always find some, your findings will probably not be reproducible and will change based on various conditions.

The distribution system is another whole ball of wax.

What I recommend is that if you haven't already, join some local HI associations and inquire with the local brethren. What we recommend here will vary regionally.

Also Mike O. has got a really good protocol list of things to do covering various systems floating somewhere about this site.

Chris, Oregon

[Scottpat]

As I walk around the house I look at the exterior unit (package or split). If it is summer, I have most likely already lowered the thermostat by 10 degrees from what the owner had it set at. I always do 10 degrees so that I will know to raise it back 10 to what the owner had it set at.

I feel the refrigerant line after about 15 minutes, if it is cold like a cold beer then I'm pretty confident that it is cooling good. If I have a concern I will take a delta-T but it will not show in my report, it is only for my information.

I listen to and for any strange sounds throughout the entire inspection. I will have the A/C running almost the entire time, most likely harder than it has run in a long time.

I look for the condensate, I hope to see water on a hot humid day! If not, I then start to look for reasons.

Just a whole bunch of things that I do that I don't even think about any more. After a few years it is becomes automatic.

In the winter, it is about the same except I'm dealing with heat. I see either gas furnaces or heat pumps, no oil, steam and on a rare occasion I might see electric resistance heat panels in the ceilings or baseboards units.

[msteger]

When warm enough to run the A/C, I turn that on (or down, if already running) when I get to the home. I want the outside unit to be running when I do the home's exterior (which is where I start my home inspections). I check the tag for Age, BTU, current ratings, line insulation, etc. and of course listen to it running.

When I get to the inside, I am happy the home is cooling because I look cold weather and detest hot weather. I run the A/C while I inspect the attic and most of the home. While doing so, I'll take temp measurements in several rooms, especially at a supply vent very near the blower.

Before I do the last rooms on the main level, I'll turn the thermostat off. Then I finish the main level and go to the basement. I'll take the cover off so I can see the indoor coil. Then, I inspect most the basement and thin get to the furnace. This would have provided approx. 20 minutes for the unit to stabilize. Then, I go turn the furnace on, watch the unit fire, check the air filter and exhaust venting, and let it run for a while. When I get to the electrical panel, I check to see what the breaker ratings are for the A/C and see that they closely match what I saw on the compressor's tag. I complete things in the basement and go check to make sure all finished rooms are getting heat. I don't remove registers or grills. Once I am confident all finished rooms are heated, I replace set the thermostat to where I found it, unless it was on in A/C. If the seller is there, I tell them to wait 15-20 mins. before turning the A/C on again.

If I find no posted service records for the HVAC system (from within the past 12 months), I recommend clean/service by a qualified HVAC tech and recommend annual clean & service to the client.

[John Dirks Jr]

Scott,

Can you describe how you that the delta-T? On what location on the system do you take the readings and how long is the equipment running before you take the measurements?

[msteger]

I run the system for at least 20 minutes (more closer to 1.5 hrs) and then take a temp measurement at a few supply registers closest to the air handler. I report whatever temp is lowest. I then take an ext. wall measurement facing the sun and report that as my ambient.