When equipment is new, it should be commissioned by checking to see that it works as intended. Re-Commission your heating and cooling equipment annually to make sure it is safe, works as intended and uses energy efficiently. This article is written from a work place point of view, but the same principles apply at home.
Definition: Commissioning Acceptance testing, Checking to see that the system works as intended, “Trust but verify”, Making sure you get what you pay for. Computer folks would call it Beta testing and de-bugging.
Definition: Re-Commissioning Doing it all again
I hate to tell you how many times I have found that equipment was never commissioned. The owner paid the bills without making sure that it did the job they were paying for.
Re-Commissioning Saves Money By:
- Reduced comfort complaints and productivity loss
- Saves on the fuel bill
- Saves on the electric bill
- Saves on maintenance cost by increased reliability
- Reduces maintainer stress by avoiding working in extreme heat and cold
- Reduces safety risk of frequent trips to the roof top or other inaccessible locations
A functional check of Heating Ventilating & Air Conditioning equipment to see if it works is not a high tech job. Adjusting, fixing problems and flame safety checks do require a qualified technician. Many technicians arrive on the job without an electronic signal generator or other functional checking tools. You should be prepared for their visit with the following:
Very Special Tools for functional checking:
Flashlights Cold Source (Ice Pack) Heat Source (hair dryer or warm hand, not an open flame) Infrared Thermometer to test with (Raytech or similar) A very small screwdriver for adjusting sensors Sensitive Nose for detecting leaking fuel (the tech should have a LEL gas meter) Two-Way Radios or Cell Phones
In addition to the checks, that the technician normally does, have them make the functional checks listed below. The technician will need help because he cannot be in two places at once. It is good to have someone from your team witness the functional checks anyway.
In most workplace situations, two crews need to work together. One crew located where the thermostat that controls the unit is. The other crew located where they can observe the operation of the equipment. This may mean one crew in the occupied areas and one crew on the roof with the HVAC unit. The two-way radios or cell phones are for the two crews to talk with each other.
Using this method, you can check the heating operation in warm weather or the cooling operation in cold weather. This will let you get ahead of the change of seasons.
Start up the unit and set it to operate in the heating mode.
Crew at the workspace thermostat or temperature sensor uses the infrared thermometer to check the temperature at the sensor. If the thermostat and the test thermometer agree, within couple of degrees, that is good enough. If they do not agree, you may need to have an adjustment made or replacement.
Wipe moisture off the ice pack and apply in to thermostat or temperature sensor to call for heat.
Roof top crew checks response of equipment. Does it go into the heating mode and start putting out heat, as it should? Does the fuel throttle valve and dampers move, as they should? Take notes about anything that is not working perfectly. Is there a smell of fuel from fired units? If there is any evidence of fuel leakage, shut it down for safety until a technician can fix it.
Crew in the workspace; apply heat Near the temperature sensor. This will make the thermostat think it is too hot. Be gentile with the heat. A warm hand on the sensor is enough.
Roof top crew; check the response of the equipment. Does the burner shut down or go to low fire, as it should. Does the throttle valve and dampers move, as they should? Take notes about anything that is not working perfectly. Is there a smell of fuel from fired units? If there is any fuel smell, shut it down for safety until a technician can fix it. Start up the unit and set it to operate in the cooling mode.
Crew in the workspace; Apply heat Near the temperature sensor. This will make the thermostat think it is too hot.
Roof top crew checks response of the equipment. Does the air conditioner compressor start up and make the cold coil cold? Do the dampers move to the correct positions?
Crew in the workspace wipe moisture off the ice pack and apply it to thermostat or temperature sensor to make it think the room has cooled down.
Roof top crew checks response of equipment. Does the AC compressor shut off, as it should?
What else should the service technician be checking?
This list is typical of what I would want the service technician to verify for a natural gas fired heating system.
Are the gas train block and bleed valves working safely? Does the gas throttle valve actuator function correctly? Is the throttle valve linkage set correctly? Does the gas valve position feedback potentiometer work is it correctly adjusted? Does the throttle valve modulate, as it should in response to changes in the space temperature? Does the burner air damper open fully during the burner start up purge cycle? Do all the positioners function correctly? Are the linkages set correctly? Does the outdoor air damper close completely when the fan is off? Does the outdoor air damper open 90% completely? Are all damper blades and linkages in good condition? Do the dampers modulate, as they should in response to changes in the space temperature? Are all the temperature sensors calibrated reasonably well? Do the temperature sensors respond well to temperature changes? Are the filters in good shape? Check the Fan: Belts, Bearings, Motor alignment, Anchor bolts, Vibration
By letting the service technician know what you expect when the job starts you will get better results. Hopefully, the technician will have a list of his own that will include other items.
Work with the service technician to improve the list for your particular equipment. Keep a copy of the checklist on file so you can use it again next year.
Click here for a free money saving report written by the Energy Boomer titled HOW SAVE MONEY ON YOUR NEXT HEATING BILL