House got high ceilings, 2100sf. HVAC unit 3.5 ton. I don't think it is big enough to cool the heat load in the house. How would you all word it out on the report?

__________________
Matt Kelekci
Houston TX

Sounds like this is beyond the scope of an inspection but if you want to try to figure it "partially"......

Need to know SEER rating of unit.
1 or 2 story house?
1 or 2 thermostats zoning system present?
Siding material, foundation material, window ratings, number of windows and sizes, attic insulation type and thickness, wall thickness..

See where this is headed?

I make no determination as to whether the unit is sized adequately for the square footage of the home. Consider having the unit evaluated for proper sizing by a licensed HVAC contractor.

What does SEER have to do with the heat load and tonnage calculations?

__________________
Matt Kelekci
Houston TX

Matt,

Being in the Houston area, it is probably considered undersized.

In the Dallas area, most HVAC contractors figure about a 1 ton per 1K of square footage.

With the humidity and heat in Houston, I would expect the same.

Most homes I see of that square footage here would have at least a 4-ton and most would have a 5 ton.

rick

__________________
Rick Hurst_Home Works Inspection Co_Rockwall TX
In the words of Mike Tyson.... "Everyone has a plan until they get hit inda mouf"

Did you mean 1 ton per 500 sf?

__________________
Matt Kelekci
Houston TX

If you are calling for a HVAC contractor evaluation, aren't you kind of making a determination that unit is not sufficient?

__________________
Matt Kelekci
Houston TX

Matt,

Yes I did, and I edited my comment.

__________________
Rick Hurst_Home Works Inspection Co_Rockwall TX
In the words of Mike Tyson.... "Everyone has a plan until they get hit inda mouf"

What checks/tests did you do during your inspection?
You obviously found some other issues, I'd hope.
While the HVAC guy is out there have him size the system and let him make the call.

__________________
badair http://www.adairinspection.com Garland, TX 75042
Residential-Commercial-Construction-EIFS-Infrared Thermography
life is the random lottery of events followed by numerous narrow escapes

"If you are calling for a HVAC contractor evaluation, aren't you kind of making a determination that unit is not sufficient?"
In a way, yes. I guess you could expand the concept to say something like " In my experience most homes of this size have at least 4 tons of refrigeration. The unit on this home is 3.5 tons. Proper sizing of an air conditioning system takes into account many factors such as cubic volume, insulation and ductwork design which are not within the scope of a home inspection. I recommend you have a heating / air conditioning contractor evaluate the system to determine if it is sized properly.
I was just trying to keep it simple.
Some of the contractors around here that actually do the calculations (few and far between) have told me that most systems they see are oversized which is in most cases worse than undersized.

I guess it really depends on your area. In Knoxville, that would probably be fine.
JF

Air conditioning sizes are done by calculations. I believe it is a Manual J calculation. Rule of thumb is 500 to 600 square feet per ton, but that is only a rule of thumb and may not always be correct. I have, on occassion (once or twice), informed my client that I was not sure if the unit was sized right, and told them that it is done by equasion, and leave them with the option to have a licensed AC company verify the proper size.

__________________
Bill Siegel
Florida Home Inspection Team Inc.

A home inspection does not involve the calculations of heat gain necessary to decide if the cooling capacity on a building is adequate, but the inspector is expected to examine and report on the rated system capacity (such as "36,000 BTUH") and on the presence or absence of cooling sources in the habitable rooms of the building.
A simple rule of thumb for relatively cool climates such as the Northeastern United States: one ton per 400 sq.ft. (Commercial) or one ton per 500 to 1000 sq.ft. (Residential) or one ton per 400 to 800 sq.ft. (Space Pak Systems). . Or a 3000 sq.ft. house may require a 5-ton unit. Or count the supply outlets: 10 outlets @ 100 cfm (estimated) = 1,000 cfm = 2.5 tons needed.