Has this winter season affected your building more than usual?
This winter weather has treated most of the country more harshly than it has in many years. In the north, we have seen high temperatures remain below zero day after day. Down south, snow and ice has repeatedly blanketed roads that are not regularly salted or plowed. Weather is fickle and patterns and trends can change anytime. Perhaps we’ve gotten soft after recent winters treating us more mildly. Perhaps it is time to rethink building design standards and construction methods to be better prepared for hotter, colder, wetter or drier conditions.
Much has changed in the last twenty to thirty years in the way buildings are planned and built. Decentralized toilet rooms, convenience plumbing fixtures and the addition of fire sprinklers have added a web of water filled pipes throughout the floor plan. Ventilation requirements force HVAC equipment to treat larger volumes of outdoor air. At the same time, economics has driven us to find the least costly materials and methods to put the pieces together. As the design is trimmed to not excessively exceed, or sometimes just meet the prevailing codes, we run the risk of coming up short when pushed to the extremes. This winter can certainly falls into that description.
There is often pressure to gain a competitive edge. Some development teams convince themselves to deny the probability as the design conditions rarely occur, or only for a couple days per year. Others just enjoy mocking the design engineer as typically overcautious. There are many forces that can attempt to guide the decision making process and pinch the performance of MEP systems to the limits on normal days. What happens to equipment performance and building comfort when the outdoor temperatures remain ten to twenty degrees below the design conditions for several days?
Strategies to minimize cold weather effects on building systems:
- Revisit air handling equipment and outside air damper settings. Ensure minimum required airflow so equipment is not overtaxed. Some mechanical code requirements reacted to “sick building” concerns and increased requirements in the mid-2000’s. Energy conservationists have dialed back those values in most recent ASHRAE standards and mechanical codes.
- Consider CO2 monitor/ control to only introduce cold outdoor ventilation air when indoor air quality requires it. Carbon dioxide (breathing exhaling) is a good indicator of occupancy and activity levels. There is no value gained by ventilating empty rooms.
- Inspect the building envelope to see that caulk remains in place, door and window seals are intact. Have the effects of wind, rain and birds opened any holes in the building?
- Inspect attic insulation. Has recent work disturbed or removed any insulation to gain access to other building components? Make sure it was put back in place correctly as it only takes a minor gap to allow a pathway to freezing pipes.
- Consider new windows in older buildings. There may be tax incentives or utility rebates to offset costs. Outdated or poorly installed windows are huge energy wasters and cause heating equipment to work hard to overcome heat losses.
- Look for potential plumbing trouble spots during the fall season (fixtures on exterior walls) and relocate piping or at least provide convenient means of isolating and draining piping in times of extreme cold to avoid costly cleanup from a burst pipe.
Don’t let the cold temperatures outside cause building occupants to be uncomfortable inside. Whether it is the place where people live or work, buildings can be comfortable all the time. Relatively simple precautionary measures can prevent complaints and expensive water damage cleanup in harsh winters. A thorough review of the construction, design and most importantly the operation of a building before it gets bitterly cold can be as valuable as any part of the long term maintenance plan. The planning and engineering that goes into a building heating and plumbing system design is based on experience and well-meaning assumptions on the behavior of the people that will occupy it. The operators and end users of a building will best know what works and what doesn’t after several hot and cold seasons have passed. Have you taken the time to verify that your building can meet current demands no matter what the weather is like?