NY Metro ASHI®
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Articles: Codes Corner Commercial vs Residential Inspections Home Inspectors to be Licensed
By: Evan F. Grugett, CCA, ASHI® #169
NY State CEO Reg. #1191-7640B
A/C INSPECTIONS – GENERAL RULES OF THUMB
Data Plates: Give make, age, capacity, electrical & pressure requirements.
1 ton of cooling = 12,000 Btuh
Old sizing: FLA rating ±7 > 7.5 amps per ton.
Floor area/600 = tons±
Current sizing: Floor area/550 = tons± (more efficient building envelopes).
Use model # on data plate to check rated capacity:
12 = 1 ton, 18 = 1.5 ton, 24 = 2 ton, 30 = 2.5 ton, 36 = 3 ton, 42 = 3.5 ton, 48 = 4 ton, 60 = 5 ton.
Fan/coils generally last longer than condensers/compressors.
EER – energy efficient ratio = Watts/Btuh
Full load conditions = 95ºF and ±85% RH (rarely exists on inspection!).
No cooling coil upstream of heat exchanger.
Date of manufacture: Condenser life is 15 to 20± years.
Exterior unit min. 10’ from propane tank.
Not by dryer vents.
On level pad.
Disconnect switch in sight of condenser.
Clearances around unit and disconnect switch.
Not overgrown with vegetation.
Better on shady side of house.
Coil ratings must be compatible with condenser size.
Size conductors and over current protection according to data plate: ±10 amps per
ton (for 1Ø equipment, 3Ø may be smaller):
1.0 ton 10 amp #14 CU wire No Al
1.5 ton 15 amp #14 CU wire #12 Al
2.0 ton 20 amp #12 CU wire #12 Al
2.5 ton 30 amp #10 CU wire #10 Al
3.0 ton 30 amp #10 CU wire # 8 Al
3.5 ton 35 amp #10 CU wire # 8 Al
4.0 ton 40 amp #8 CU wire # 6 Al
5.0 ton 50 amp #8 CU wire # 4 Al
Thermostat wire not inside the electrical conduit.
Through wall units are mostly old and at end of useful life.
Multi-gang units must have proper separation so they don’t share/mix air.
Condensate line penetrations of wall must be caulked & sealed.
Out of level, unit usually on backfill around foundation.
Cannot drain to public way.
Drain pipe min. ¾" with 1/8"/foot pitch.
Can drain to indirect receptor (lav., tailpiece, or tub overflow).
No direct connection to waste or vent pipe (DWV system).
No drilling of DWV pipes (saddle fittings) to accept condensate drains.
Secondary drain &/or pan required for equipment above framing.
Secondary drain pipe to conspicuous point of disposal.
Water detection device (float switch) in pan in lieu of secondary drain pipe.
Drains to gutters can be clogged.
Not discharged directly onto flat roof surfaces.
Design for cool air flow, it’s heavier than warm air.
If designed for heat only, may not cool properly at end of system.
Firestop penetrations through floors in concealed spaces.
No duct openings in garage.
Minimum 24 gauge sheet metal in attached garage.
Two story maximum vertical rise on factory made duct.
Flex duct support: Horiz. 1½" strap @ 4’-0" o/c, sag max. ½" per 4’.
Vertical 6’ max. o/c.
Holes, open joints, in plenum at coil = air leakage.
Insulation in unconditioned spaces (now R-12 was R-8), with foil vapor retarder.
Room by room return in older systems better than central returns.
Not from bathroom, kitchen, furnace room, closet, or other dwelling unit.
Minimum 10’ from natural draft appliances combustion chamber/draft hood, or wood burning fireplaces.
Sufficient volume = 25% of areas served or hallway must have 3 doors to area served.
Minimum size 6 sq in/Kbtuh output rating or manufacturer’s spec.
Old houses may lack return air at upper floors.
High return grill placement with cooling only systems, warm air is forced to upper floors or high in room.
High – low placement in older houses.
Dampers on registers for adjustment.
Close registers in winter in systems with separate heating.
Can’t be next, or close, to return air grill.
We’ve all done residential inspections on single family homes, and we’re all pretty good at it, or we wouldn’t be here, right?
That’s fine for residential, but what what do we do with those requests we all get from time to time for COMMERCIAL inspections?
Don’t turn business away because you may not have done any commercial inspections.
Strictly Business Commercial Inspections does both, and can help you when you get those occasional requests for a commercial inspection!
How are commercial inspections different from residential?
To begin with, commercial clients have a very different perspective on the purchase, the property, and what answers they are looking for from your inspection report.
Home buyers want to fall in love with a house.
Commercial buyers have a specific use in mind for their building, whether it’s an apartment house, a hair salon, or a gas station with convenience store.
Emotions rarely, if ever, play a part in their purchase decision.
When a commercial buyer looks at a building (or YOU look at it FOR him), he wants to know whether this building will support his business needs. If there are problems with the building, he wants to know what, if anything, he will have to spend before he can use it for his intended purpose.
His "bottom line" question (which you are there to answer) is "What will I have to do and what will it cost me before I can open the doors to the public, and start making money here?"
What do you do differently for commercial?
What you do the same is describe the property and report on any defects you see. You still have to inspect the foundation, walls, roof, etc, and tell the buyer where the problem areas are, just like for residential inspections.
What you do differently is to evaluate the property from the point of view of the buyer, and what he intends to do with it.
For example: Suppose you are inspecting a building with a new 40 gallon gas hot water heater and 100 amp single phase electric service for a buyer who wants to set up a laundromat with 50 washers and 30 dryers … The hot water heater may be new and the electric service may be perfect, but they won’t meet his needs.
You would have to make a recommendation for a plumber and electrician to upgrade to two 125-gallon quick recovery hot water heaters piped together, and a 250 amp 3-phase electric service with associated circuit breakers and new wiring. He would also need an upgraded natural gas service if he wanted to use gas fired dryers.
How would the report be different for COMMERCIAL?
Besides describing what’s there, and what condition it’s in, you would also describe it in relation to the intended use…
"40 gallon gas fired HW heater model.xxxx…. Good condition, inadequate for intended use of property as a laundromat… Recommend 2 125 gallon……".
The report would also have more headings and categories to reflect specialized equipment that might be there (such as an elevator or a trash compactor).
The electric and heating/air conditioning descriptions might have to be broken out to show the distribution of power and heat to common uses such as hallways and lobby, and how much to apartments, if it was an apartment house.
You might also need to comment on items the buyer would need that are not presently there, such as a (cooking) exhaust hood and fire supression system if the buyer wanted to open a restaurant. A cooking exhaust hood would need ducting, similar to that used for fireplace flues, run to the roof or rear of the property, and that might not be possible in the property the buyer was looking at.
In writing your report, remember that the buyer wants to "open the doors" as soon as possible, and spend as little as possible.
Your report must provide the commercial buyer with a prioritized list of recommendations for things that "absolutely have to be done", and things that would be nice to do when cash flow catches up.
Needless to say, conditions that constitute safety or health hazards, or items that are required by law such as the cooking exhaust hood for a restaurant, make the top of the list.
Things that will result in on-going damage to the building if they’re not fixed (such as a leaking roof) also head up the list.
Compliance with fire safety and liability requirements are also a part of the inspection and report.
These include emergency exits (with proper doors and latches), emergency lighting, fire extinguishers, and similar items.
With a residential inspection, there is a limited list of specific things to inspect.
When doing a commercial inspection, be prepared to inspect everything.
"Everything" can include 3-phase electric power, HVAC units located on the roof, elevator machinery, steam or hydronic boilers (which may be the size of a living room with a flue pipe 2 feet in diameter), and fire sprinkler systems.
There may be specialized industrial machinery particular to the industry that the buyer will be setting up his building for. If there is, you will need the cooperation and participation of the seller and the buyer to test it.
Learn more about commercial inspection
Strictly Business Commercial Inspections has done over 500 commercial (and residential) inspections, and has inspected everything from apartment houses to gas stations, and even churches.
Don’t turn away business!
If you get requests for commercial inspections, refer them to
Strictly Business Commercial Inspections.
We’ve "been there – done that", and can handle your commercial inspection requests on either a commission basis, or on a reciprocal referral basis. We do residential inspections too!
Ira Eisenstein can be reached at 908-202-2208, or email@example.com.
See our website at: http://www.strictlybusinesscommercialinspections.com
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