Consultant finds multiple causes for arena's icky air. McMeeken may re-open next week

The arena re-opened on Mar. 9 after the city had enacted all recommendations made by engineering consultant MET Energy Systems.

 

But ten days later, a newly installed carbon monoxide alarm sounded in one of the McMeeken's dressing rooms and concentrations of 56 parts per million were detected.

 

The arena was then closed until further notice.

 

On Mar. 21,the McMeeken's Zamboni again fell under suspicion when it was taken to the John Rhodes Community Centre to help with ice resurfacing and within 10 minutes elevated carbon monoxide levels were detected there.
 

Here's what Nor Mech Engineering is now recommending:

The following is the full text of Nor Mech's McMeeken report:

During our site investigation, we were accompanied by Jason Mihailiuk at the city, as well as two HVAC [heating, ventilation and air conditioning] service technicians from Henderson Metal (Jason White and Travis King) that happened to be on site replacing an old faulty gas-fired atmospheric domestic hot water tank behind the canteen.

 

The following is a summary of observations made, complete with our recommendations to further assist the city in correcting existing facility deficiencies and eliminate possible pollutant sources, particularly with respect to the existing old heating and ventilation systems:

1) Upon arrival on site, we constructed similar conditions to how the facility would normally operate during ice resurfacing, but less the Zamboni operation. While the rink exhaust fan and makeup air louvre system were operating, we opened and closed the main front entrance doors to the arena, simulating patrons coming and going. It was observed that there was a very significant 'pressure differential' in the building, with the corridor leading down to the change rooms acting as a wind tunnel. It was significant enough, that the hair on your face would blow in the wind. These corridors are basically open to the arena at the north end, so this corridor is acting as further makeup air for the rink, during the resurfacing and operation of the large evacuation exhaust fan at the south end of the rink.

2) It should be noted that it is not problematic that there is a negative in the building when the ice resurfacing process is underway. In fact, for an older building like the McMeeken you actually want the negative pressure differential, so that fresh makeup air is drawn into the rink, to dilute and purge the rink from pollutants such as from the gasoline operated Zamboni while it is cleaning the ice. However, one significant problem is that gas-fired atmospheric type equipment do not operate properly with negative pressure issues, and can experience chimney down-draft issues, whereby makeup air can be drawn into the building down the chimney flues, instead of the equipment flue gases rising up and out the chimney.

3) The two existing gas-fired furnaces that heat the lobby, canteen, and change rooms have their return air pulled from the corridor. Both furnaces have been upgraded to sealed-combustion higher efficiency furnaces, so they will not be adversely affected by the building's pressurization differential during ice-resurfacing. However, since the return air for the furnaces pull from the corridor, any contaminants or odours present in the corridor would easily be re-circulated back to furnaces, and distributed to the canteen, lobby and change rooms. This explains why the carbon monoxide from the canteen DHW [domestic hot water] tank was so easily distributed into the lobby and change rooms.

4) Upon further investigation, it was observed that due to 'pressure differential' in the building, the atmospheric DHW tank behind the canteen was experiencing chimney flue 'down-draft' conditions, so that the products of combustion from this atmospheric DHW tank were not rising up the chimney, but instead were spewing down into the mechanical room and making their way into the corridor, where they were quickly swept away down the corridor, and the contaminants were drawn into the heating furnace return air grilles, where they were re-distributed to the change rooms and lobby areas. We
witnessed and felt the the downdraft in the chimney, when we conducted the above simulation. This faulty old DHW tank seems to be the more-than-likely culprit to the latest carbon monoxide incident. It is our recommendation that this DHW tank that serves the washrooms and change rooms be replaced with a sealed-combustion (direct vented) type of unit. The city was already in the process of implementing this DHW tank replacement with Henderson Metal.

5) It was noted that the zamboni room also has an older atmospheric-type DHW tank, as well as a very old atmospheric-type, gas-fired unit heater with standing pilot (i.e. open flame for ignition). Atmospheric-type equipment with a standing pilot can be very susceptible to improper operation and flue venting issues, when a building is in a negative pressure condition. In fact, during our site investigation and simulation exercises, we noticed the unit heater 'misfire' on two different occasions, proving that the unit heater was being negatively affected by the pressurization issues. It is suspected that these two pieces of equipment were contributing factors to the carbon monoxide incidents. It is our recommendation that the old atmospheric unit heater be replaced with a scaled-combustion (higher efliciency) unit heater, to eliminate these issues. 
It is also our recommendation that this DHW tank that serves the zamboni, be replaced with a sealed combustion (direct-vented) type of unit. The existing electric buffer DHW tank can still be utilized as additional storage and buffer tank for high-use occasions. The installer should also provide a small potable expansion tank, as it was noted during the site investigation that there is significant thermal expansion (i,e. water pipe hammering). This expansion tank would correct that deficiency, and eliminate noise and potential future pipe/fitting leaks from the shaking pipes. The same potable expansion tank should also be added to the smaller new DHW tank that is being installed beside the canteen. These equipment replacements (upgrades) should be completed prior to the facility re-opening.

6) We reviewed the operation of the existing gas-fired radiant tube heaters [RTHs] in the rink above the bleachers. These RTHs operate with a flue vent evacuation fan, creating a positive suction to draw all the heated flue gases through the tubes and out the building exhaust vent. However, we did notice that this evacuation fan stops when there is no call for heat, which in theory, means that it leaves some flue gases (products of combustion) within the tubes. It is our recommendation that a relay be added to this RTH evacuation fan, to introduce a "post-purge" time delay, such that the fan will continue to run for 1.0 to 1.5 minutes to ensure that all flue gases are evacuated from the tubes, before turning the fan off. This will eliminate any possibility of flue gases leaking into the rink, perhaps during times of ice resurfacing and the rink is under a 'negative.' This equipment upgrade should be completed prior to the facility re-opening.

7) The main rink exhaust ventilation system was also reviewed. We attempted to get model number information off the old existing rink exhaust fan, but the nameplate is old and unreadable. Cross-referencing the physical size of the existing fan and motor, as well as the actual amperage load on the motor with exhaust fan performance charts, it appears that the exhaust air rate of this fan is 15,000 CFM [cubic feet per minute]. For a rink this size, ASHRAE 62.1 only requires this exhaust fan to be 12,000 CFM. Therefore, the existing exhaust air rate for the rink appears to be more than adequate and meets the minimum exhaust air rate required by code. We then reviewed the existing incoming makeup air intake (motorized damper) louvre at the north end of the building. It was found to be properly interlocked with the large rink evacuation exhaust fan at the south end of the rink, as they should be. Due to the excessive 'wind tunnel' effect in the change-room corridors from the lobby exterior doors, it was suspected that the existing makeup air intake on the north end of the rink might be too small. After further review of the existing louvre, it has been determined that this intake louvre is too small. Actually it is only rated for 7,500 CFM, and so it is 50 per cent the required size that it should have been. Also the existing fresh air intake's location does make it susceptible to drawing in exhaust from idling automobiles out in the parking lot. In the short term, it is recommended that the city install an additional second intake louvre (approximately five feet wide x four feet high) on the east wall of the arena, located in between the north players bench and the northeast corner of the rink. This louvre motorized damper would be tied into and work in unison with the other existing motorized damper.

8) The existing arena does not have an automatic gas detection monitoring system interconnected to the rink ventilation/exhaust system. Upon review of the Ontario Building Code and the Ontario Recreation Facilities Association - 'air quality for arenas' standards, the existing arena does not require to have an automatic system, as long as it does have a means of removing 'air contaminants' such as a manually activated rink ventilation/exhaust system, coupled with regular air quality testing procedures, regular maintenance for ice resurfacing equipment, etc. However, I should point out that the code also stipulates that the building systems should be designed using "good engineering practice." Based on that statement, it is no wonder that most arenas do in fact have automatic gas detection monitoring systems, as well as some also go so far as to interlock the ice-resurfacing gates so that when the gates are opened, the system automatically turns on the rink ventilation system, and do not rely on manual operation that make it susceptible to human error. 
At the very least, it is our recommendation that in the short term, the McMeeken Arena have an automatic gas detection monitoring system installed and interconnected to the existing rink ventilation/exhaust system; and continue to be diligent with manually turning on the ventilation system and following the arena's established ice resurfacing procedures and protocol.

9) The existing change-room ventilation system is crude and does not meet current code requirements. If this were a new facility, these rooms would be exhausted and ventilated using an energy-efficient heat recovery ventilating system that would not only provide proper exhaust air exchange, but also bring in replacement fresh air too. However this is an existing condition and does not have to be upgraded.

10) However, while reviewing the change-room areas, it was noted that there are existing change rooms that are lacking exhaust air (i.e. old exhaust fans are burnt out and not functioning) or they do not have any proper 'sanitary' exhaust air provisions at all. These change rooms must have exhaust air provisions, as required by the Ontario Building Code. It is recommended that any change room that has shower/washroom facilities have their old exhaust fans replaced. The existing referee change room and change room #4, which have both shower and washroom facilities, do not have any exhaust provisions at all. This is a code violation and needs to be corrected. Once all required exhaust fan provisions are installed, they should be interconnected to respective change room light switch, so that if change room is being used (i.e. lights are on), so too is the exhaust fan. These equipment replacements (upgrades) should be completed prior to the facility re-opening.

11) For the interim, it is recommended that a six-inch diameter thermally insulated fresh air duct be added to each furnace return air plenum, to bring in some fresh air for the change rooms. These fresh-air intakes would work in conjunction with the new sanitary exhaust fans to bring in makeup fresh air, and help ventilate and purge these rooms of smells and odours. This is certainly not the perfect fix or system (refer to item 9 above), but it will definitely help, and at very little cost.

12) It was noticed that the northmost furnace (which was just recently replaced) does not have return air provisions for the majority of the rooms that it serves, including the referee room that actually has the furnace thermostat. It is recommended that the high side wall R.A. grille in corridor be modified (i.e. partially blocked off) such that it only returns approximately 200 CFM (eight-inch diameter duct), and most of the return air for this system come from new return-air ductwork that can be installed along the ceiling at the west wall of the change rooms, with return air ductwork branches added to referee room, and change rooms 3 and 4. This will greatly improve the furnace operation and ventilation of these rooms.

13) Coincidentally, on the evening of Mar. 21, the Zamboni at the John Rhodes arena broke down, so the city staff floated the McMeeken arena gasoline-powered Zamboni over to the John Rhodes. After only using the McMeeken Arena Zamboni for 10 minutes, the city staff reported that the John Rhodes automatic gas detection system went off on first stage reading 35 parts per million of carbon monoxide. Based upon this recent incident, our office recommended to the city that they should immediately get the McMeéken Zamboni (which has a four-cylinder Ford engine) reviewed and serviced at a local Ford dealership, including obtaining another emission test. Preliminary results from Highland Ford are that the Zamboni does require servicing maintenance work, as it has a faulty oxygen sensor that needs replacement, its carburetor is leaking/faulty and needs to be replaced, and its muffler has several leaks that should be repaired. These Zamboni deficiencies could very well have been contributing to the carbon monoxide issues at the arena. The catalytic converter was tested and reportedly is functioning properly, At the time of writing this report, the city was still awaiting for a final service maintenance report from Highland Ford, including results from a second emission testing.

14) Lastly, the city facility maintenance staff were able to show myself the conditions of the Cimco dehumidification unit filters that were just changed. It was noted that the filters were completely 'black' with soot-like material on the media, instead of what should normally be dirty grey-coloured filter media. The conditions of this filter media further reinforce the fact that there is, or has been, excessive airborne hydrocarbons present in the arena, which is more than likely from the Zamboni and/or ice edger; and possibly also contributed from the bleacher radiant tube heaters and/or the old atmospheric-type heating equipment.

Conclusion

We do not think that the recent carbon monoxide issues were all solely due to one piece of faulty equipment. It appears that there were several potential sources, such as the Zamboni, the two old atmospheric type DHW tanks and old zamboni room unit heater, former old furnaces, lack of a 'post- purge' control on the radiant tube heater's vacuum fan, as well as from possible human error whereby there may have been incident(s) where arena staff may have inadvertently not followed the ice-resurfacing protocol/operational procedures including some of the new recommendations that were just recently suggested on the earlier consultant's report.

Before reintroducing the Zamboni back into the building, the Zamboni should be repaired and serviced. Similar 'servicing' is recommended for the ice edger toò. [t is recommended that à regular periodic service maintenance program be implemented for both the Zamboni and ice edger.

It is also recommended that before the building is reopened, that all atmospheric-type equipment be replaced with new sealed-combustion type units, so that they are not adversely affected by negative building pressure during ice-resurfacing procedures. This new equipment could be easily incorporated and relocated into a new arena facility if/when it is constructed. Also, these newer units will be more energy-efficient, which will also help reduce building operating costs, (It should be noted that the city has already begun the process of completing these equipment replacements.)

In addition, the exhaust and ventilation systems for the change rooms should be implemented immediately, in order to correct existing code deficiencies and help improve conditions within these rooms. This needs to be completed before the facility is reopened for public use.

Lastly, we strongly recommend in the short term that an additional MUA louvre be added to the existing rink exhaust ventilation system, and a proper automatic gas monitoring system be installed for the rink with gas-detection sensors installed throughout the facility.

Again this new gas monitoring system should be considered not only as an added safety precaution, but also an investment that could be easily incorporated and relocated into a new arena facility if and when it is constructed.

If you have any questions or concerns, or wish to discuss the above further, please do not hesitate to contact my office.

Sincerely,
David J. Barban, P.Eng. consulting engineer

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