4 FM quick reads on HVAC
1. With HVAC Upgrades, Reduce Loads First to Maximize Energy Savings
Today's topic is the importance of trying to reduce loads before replacing HVAC systems..
HVAC equipment is expensive and long-lived. What's more, these systems are sometimes so large that it is difficult to get new units into place without significant construction costs. So it's no surprise that decades may elapse between the time a boiler, chiller or air handler is installed and the day it is replaced.
The demands on an HVAC system depend to a considerable extent on the performance of other building systems. A one-story building in Texas, for example, will cost considerably more to cool if it has a conventional black roof than if it has a reflective roof. The same building in Minnesota will cost more to heat in the winter if it doesn't have adequate roof insulation.
The roof isn't the only part of the building that has an effect on HVAC loads. Solar gain through windows, air infiltration, heat load from lighting systems – all have some effect on HVAC loads. So does equipment from computers to coffee makers. And improvements can be made in all areas.
The time to consider building system improvements and other load reduction measures is before a major capital investment in new HVAC equipment. If the load on a system can be trimmed, it may be possible to reduce the size of the HVAC unit as well. Optimizing the performance of the air distribution system may provide an opportunity for further reductions in chiller or boiler size. And the savings provided by the smaller units can be used to help pay for the load-reducing measures, or for more efficient HVAC equipment.
More widespread use of energy modeling software makes it possible to evaluate what-if scenarios more easily than in the past. Although energy modeling adds cost, that cost may be justified by the savings available from load reduction and HVAC savings. What's more, if energy savings are great enough, the project may qualify for federal tax deductions under IRS Section 179 (D), widely known as EPAct tax deductions.
By looking at load-reduction measures in conjunction with HVAC system replacements, facility executives may find cost effective ways to lock in lower energy consumption for several decades.
Understanding Why Employees Resist Change
Today's topic is BAS start/stop functions.
A basic control function is simply to schedule HVAC equipment to turn on and at given times. It's always worth checking to make sure that this capability is being used. In some cases, it may have been turned off in an attempt to meet a temporary need, then not turned back on. In other cases, the facility staff may be hesitant to shut down heating and cooling if occupants are in the building late at night. But even a very late stop time – midnight, for example – will save energy and money compared to round the clock operation.
BAS start/stop optimization programs can do far more than simply on/off scheduling based on time of day. They can analyze outdoor and indoor temperatures to determine when equipment needs to be started. They can also schedule equipment operation to ensure that wear on boilers and chillers is as evenly distributed among all units as possible.
These powerful programs can save energy and extend equipment life. That's why it's important for facility executives to ensure that start/stop optimization capabilities are being taken advantage of. It's also important to ensure that facility operations staff understands the value of start/stop optimization. Otherwise, there's a chance that they will disable it. Finally, it's important to have schedules checked periodically to ensure that they are still in synch with building occupancy.
Reducing HVAC First Costs and Operating Costs
Today's tip concerns saving money on HVAC costs.
The time to start thinking about HVAC is at the very start of programming a new building. That's because life-cycle HVAC costs for a new building are often locked in before the efficiency of chillers and boilers has even come up for discussion.
The siting of the building, for example, will affect solar gain. The choice of windows can influence both heat transfer and solar gain. Likewise, the level of insulation in the walls and roof plays a significant role in determining the operating cost of the HVAC system. And the type of lighting system used in the facility will have some effect on heating and cooling loads.
It's not just energy costs that can be saved. Smaller loads translate into smaller chillers, fans and boilers, reducing first costs as well as operating costs.
Specifying efficient HVAC equipment is important, of course, but by the time talk turns to manufacturers and model numbers, many of the most important decisions regarding HVAC efficiency have already been made. That's why it's useful for facility managers to get involved as early as possible in programming.
Find Allies to Win Funding for Facility Projects
Today's tip has to do with winning top management approval for facility projects.
Gaining funding for a project is a challenge all managers face. Top management has to weigh projects from across the organization, then allocate financial support to the ones that will ultimately provide the most benefit to the entire organization.
One way to improve the case for a facility project is to show that it will provide direct benefits to other departments or business units. For example, if the facility manager wants to upgrade aging parking lot lights, energy savings may only be one benefit. By talking to other managers or the human resources department, the facility manager may be able to show that the dim, yellow light from old fixtures makes employees who work late nervous as they walk out to their cars.
Similarly, it may seem obvious to the facility manager that an unreliable generator in a hospital or a Tier 1 data center needs to be replaced. But if the proposal to replace the generator has the support of the head of medicine or of IT, it stands a much better chance of being approved.
There are plenty of other examples, ranging from new HVAC equipment that will save energy and reduce maintenance costs while addressing employee complaints about comfort to a new access control system that may reduce liability while making employees feel safer. The key is to think broadly about the benefits of a facility project.
Taking that approach provides the facility manager with an ally in the battle for funds. It also shows top executives that the facility manager is taking a company-wide perspective, rather than simply looking at the needs of the facility department.