Defrost Cycle of a Heat Pump. Please proof this new inspection article.

http://www.nachi.org/defrost-cycle-heat-pump.htm

While this may be true, officially stating this from an association standpoint has opened the inspector up to a possible lawsuit. The question comes down to what is “professionally trained”

In the above quote, please explain what “identification” means?

Also, in the above quote, I disagree with the 2nd identified statement. We, are generalists, not experts. This is beyond our responsibility and we may ultimately provide incorrect information on maintenance.

I would agree, to a point. The word “thoroughly” is too ambiguous, and runs contrary to the realities of performing a visual, non-invasive inspection. In fact, it helps to incorrectly set the Client’s expectations. We consider it to be “thorough”, but our perception, the Clients, and the HVAC expert may all have differing views. Also, the notion of justifying one’s obeservations must be couched, specifically, within the true and intended scope of the SOP; that is to identify the readily apparent conditions observed of readily accessible components and systems at the time of the inspection using non-invasive and non-destructive inspection techniques. Let’s not lose sight of any of this.

Emergency or auxiliary heat is also an individual cycle.

Frost on the outdoor coil is not a defect by itself. Depending on outdoor conditions, Frost is a common occurrence.

Ice usually extends beyond the protective grills or outdoor cabinet, not just a frosted/iced coil. This condition should go away within an hour if the system is functioning properly.

It doesn’t matter what the temperature drops down to for the device to activate. Many devices operate at different temperatures and thermostat settings. Most defrost thermostat operating well below the 32° point. In order to absorb heat, the outdoor coil must be substantially colder than the outdoor air (as much as 30°). This means that when its 60° outside, the coil is below freezing (32°F). If 32° were used, the unit would defrost every cycle on a winter day.

Some defrost systems also include pressure switches that correlate temperature through pressure.

Also, air pressure switches are frequently used to detect the amount of air blockage from Frost on the coil.

I just received an e-mail from Ben G, where he has announced the sale of a new video on this subject. The funny part is that the “introductory” content includes the article as written above, less any changes or advice.

Good points, but we won’t be adjusting the article based on those points.

That’s fine…

We can refer to the post when half educated HI’s’ ask at a later date.

Defrost is a very complex operation. I made $thousands/mo in the winter taking care of this single issue…

As a matter of fact, my $400 inspection two days ago had a condenser fan invoice for $480 on the table.

It makes me think about going back into service! :wink:
I spent 6 hours, they spent 1…

However, there are few and far between willing to pay that much for an $80 fan motor!
:slight_smile: