AC condenser undersized - HI said nothing - to blame?

Some opinions please.

An agent at an inspection the other day tells me the plight of a family member of hers…

Bought a home, 80’s construction. Alum. Dual Pane Windows. 2 story nearly 3200 sf, with basement, which isn now finished. Originally unfinished basement.

Not sure of Furnace size, but, the Condensing Coil was sized at 2 tons:roll:

She asks me what I think as she advised her family member to get 3 estimates, notify the HI of the oversight and “discuss”. From what I gathered of the conversation, it sounded like estimates were obtained and this was headed to small claims. This is in an area that is regularly getting in the high 90’s on a daily basis and the upper floor is not cooling below the low 80’s

Anyway, my response was that:
HI’s don’t generally determine sizing of units, but it’s fairly obvious that 2 tons is undersized for this structure. We advise if the unit is “functioning”, not properly sized.

I also asked if the structure had additions. “Yes, the basement was converted” BINGO!

I indicated that although I felt on one hand that an experienced HI would notice that the unit was very undersized, I would have also inquired if this converted basement was permitted, as the space is likely to have threw off whatever calcs were originally thought of.

To me, this one is sooo undersized, I would have commented on it. But, do we say something about a 2 ton unit on a 1500 sf house… 2000 sf house? I mean, GEESH a 2 ton unit on a home over 3000 sf, in a hot area?

You get my picture.

I would think that if this one ends up in Small Claims, the HI gets fried there, unless he had something indicating a need for a 3rd party to come look at the AC unit by COE. I was told there wasn’t, but haven’t seen the report.

Is the system zoned?

Where is the house?

Are we sure about this?

How is the duct designed?

Where is it located?

Did they add the basement to this system?

How many and where are the returns?

How many and where are the supply registers.

Where is the thermostat?

What is the duct Air Leakage Rate?

What is the Duct Insulation rating?

What is the construction of the duct?

Where are the TAB duct dampers located? What dampers?!

Is the Barometric Damper properly adjusted?

What is the negative static return air duct pressure.

What is the friction loss design pressure of the duct design?

What is the CFM capacity of the furnace?

How much Insulation in the attic, walls and under the basement floor? What is the R-Value of each?

What is the U-Value of the windows?

What is the orientation of the house?

Is it shaded? To what extent?

How many ACH/hr does the house have?

What is the CFM of ventilation (mechanical)?

What is the normal building static pressures?

Where is the Neutral Plane?

Where in the house are they uncomfortable, what season?

Just a few questions then, I can take a stab at a “wild *** guess” from here!

And Lastly, why does she think a Home Inspector has ANYTHING to do with ANY of this?!

Once it gets to court the HI lost… :frowning:

Hard spot to be in, technically I would say the HI is not liable for the undersized AC…

Home Inspectors do not calculate heat,electric or A/C systems.

<---- Scary, I agree. My thought too. But David, are there realistically any scenarios where a 2 ton AC would be sufficiently sized in a region that gets hot like that?

The other parts I did delete, I wasn’t really told any more than that. But I realize that there are a lot of variable that you are pointing out!

BK… I agree there too! From the sound of it, he’s already lost!:frowning:

I agree.

But, I posted this as the 2 ton size of the condensing coil vs a 3200 sf house in a hot area…

Just puttin’ in out there for thought.

If the inspector has a pre-inspection agreement describing the SOP he will use signed by him and the client, has no advertising promising to “exceed” the SOP, and inspected/reported in accordance with the SOP…he has not problem, whatsoever.

Why are you “puttin’ it out there” at all? It’s beyond the SOP period.

Yes, we all exceed the SOP at various times for various reasons, but “missing” something that is outside the SOP should be the NORM.

Good Points, as I’ve said, I agree with our “duties”.

The SOP is the SOP.

The reason home inspections run close to $400 instead of $4,000 is because they are quick (three-hour) non-invasive and unscientific observations. It doesn’t really matter who you are…less than a complete Manual J calculation for sizing the unit and ductwork is a guess. Calling out an undersized unit as a material defect is outside the scope of a home inspection.

I think you were wrong to tell the client that it was “obvious enough” for the HI to call out.

Wrong? Maybe, maybe not? I can assure you that I let it be known that an inspection is not to determine the size/adequacy of appliances like this.

After all, this was at a HI I was performing, I had a vested interest in explaining such things.

But, just as I would comment about a 30 gal water heater in a 5 bedroom 3.5 bath home, if I noticed that a 2 ton unit was serving a 3200sf home, I’d probably make mention of it, especially if there were alterations/additions to the property. Do I have to? Nope.

In most states, the sole person LEGALLY qualified to calculate the size of an HVAC system is a PE.

This is far beyond the scope of a home inspection. Providing the HI colored between the lines, he should be okay.

David Anderson provides an excellent range of questions that are considered when evaluating the needs of a dwelling and sizing the HVAC properly. While he may have the wherewithall to comment intelligently, a majority of inspectors simply do not.

I can almost guarantee that what David rattled off the top of his head were things not learned in any HI class…

Good point Joe… David’s list may and parts of this post may be a good reply some day…

I would probably do the same thing Tim but that’s just my opinion

How many inspectors include the size of a system in the report.

In a hypothetical situation (in which none of the points brought out in this thread are to be considered), the answer to your question as to if it is feasible to cool a house that size with a 2 ton air conditioner, the answer is yes, very possible!

Obviously this is totally dependent upon the construction of the house and the design of the HVAC equipment.

If a 24,000 BTU per hour air-conditioning system is capable of cooling a house 1500 ft.² home at outdoor design temperature/humidity for this climate some, it could perform easily.

Simply looking at your fenestration construction, this is highly unlikely. As I said were not using any of the specifics here.

So yes, it could possibly work. And no, it is not the responsibility of a home inspector. And again, no, it is probably not even within the capability of most HVAC contractors!

Sounds like a witchhunt to me.

If you wish to make any comments about the fact you have given, I see no indication there is a return register on the third floor which is where it’s hot.

Fact number one: Hot air rises.

You cannot get hot air on the third floor down to the air-conditioning system if you don’t have a return register installed there!

So in light of this simple fact, the system will never work properly because it was never designed properly, regardless of how many tons of air conditioning you force to that house, it will never work.

Fact number two: the system was modified since the inspection and the home inspector has absolutely no control or responsibility of how screwed up they made it since his inspection.

I would back out of this one gracefully (if you work for the realtor), if not I would call it like it is!

As Home inspectors we may not have to be knowledgeable about capacities or efficiencies of air conditioning or heating systems, however some education and knowledge about how air conditioning and heating systems operate is helpful and I am sure that most of us HI have some knowlege about the systems and how to operate them. I always note the capacity of the condenser assy vs the Evap A-Coil (if I can see the listed labels) and If a unit is undersized for the ASF of the living space I will confer with my client about this because there are many variables to consider especially the age of building and any energy conservation aspects of the building. Tim, I am with you, the client needs to know that a 2 Ton condenser and Evap coil is maybe too small and warrants further evaluation by a HVAC contractor, especially after operating the cooling system and only the lower area of the building is cooled. We need to cover our arces because if we don’t we all know the consequences. Education and knowldge is the key!

As a generalist and home inspector.

I have the SOP and Ben Gromicko’s disclaimer on the intro of the heating pages.

I explain to determine if the system is sized properly the HVAC specialist (Not me) needs to calculate a manual J and figure conditioned sq.ft, window types, insulation and whatever else is required.

I only run the system to see if it operates, check filters and look at various components of the system. (Sequence of operation, burner flames, vent/chimney, ect…

If I do not see a recent record of service the system is called out for a system clean and check by a qualified HVAC specialist before the close of escrow.

I have been noting the tonnage of the exterior condenser with the description of the system. (need to rethink on if I really need to do this, tonnage that is!!)

Many homes around here have add on,s like basements, third floor with the original system. ( I note that the system may be under or over sized but you need the specialist to determine)

Dave A is a home inspector (Generalist) but it sounds like he has the knowledge and background so he is also a specialist. ( I am sure the understanding of building science has helped you along the way)

Good luck with the potential claim, but you should not be liable if you followed and noted the SOP.

I suppose a better question here is, “How many inspectors go over what the inspection covers, to what depth and the limitations of a visual inspection” before they ever start. It only takes a couple of minutes and for me has been a central part of NOT having this kind of misunderstanding. Then further explain that anything beyond that requires the services of a licensed tradesman in that discipline. Then I go over this again at the end when we are finished. Is the inspector in too much of a hurry to get that on site report generated and get to that next inspection and doesn’t take the time to make sure the customer understands ALL of the issues with the home? Or does the inspector just provide the customer with a copy of the SOP, which they know the customer will never read, and hope for the best.

It is the easiest thing in the world for an inspector to simply say, not just in writing, but actually SAY to their customer, " I AM NOT QUALIFIED" to make that kind of determination and you will need the services of a licensed HVAC (or electrician, or plumber, etc.) contractor. Trying to appear that we know everything is what is the root cause of this. No one wants to admit they don’t know something and it is going to start biting people in the ***, or already has.

I always do