Most people are aware that stop-and-go driving in town consumes more fuel than smooth steady changes in speed on the highway. The best option on a long journey is cruise control.
The same principles of cruise control apply to the heating systems in buildings. Boilers starting and stopping with old mechanical limits burn more fuel than a system operated with temperature-sensitive digital controls.
The last few years have seen tremendous gains in digital technology for comfort control and fuel savings in heating systems. The average fuel savings offered by a modern control is 10%-25% with a 1-3 year payback.
The energy savings result from matching the heating water temperature in the radiators to the outdoor temperature. The warmer it is outside, the cooler the heating water becomes. Many buildings were designed to operate with heating water temperatures of 180°F to 200°F on the coldest day of the year. Most of the year Vancouver Island is well above the coldest temperature.
This means you can heat your building with a lower water temperature. Lower temperatures result in less heat loss, less radiator noise and lower fuel bills. Heat the building automatically with the lowest temperature possible for the outside air temperature.
These factors will influence your fuel savings:
• How fast the building loses heat. This is dependent on building design, insulation and windows.
• The type of radiators in the building. Different styles of radiators operate at different water temperatures.
• Tenant expectations of heat. Some tenants fully expect a tropical experience in their suite at your expense. This may be for themselves, their birds or
plants. We have met a few of these people over the years. You are only required to provide 21°C. Many owners keep the temperature higher to accommodate
long-term elderly tenants. If the room temperature needs to be higher, the fuel savings will be limited. There have been instances where we recommended
against installing any modern controls due to the age and lifestyle of the tenants. The first consideration is always the occupancy of the building.
• It’s 21°C but I “feel” cold. This is actually known as the cold 70’s. The air temperature is correct but there is enough radiant cooling from the walls and windows to feel cold. This is identical to walking down the frozen food aisle and feeling cold even when the air temperature is the same as the cereal aisle at the grocery store. If the tenant needs the heating water turned up 15°F this shows up as a 5% increase in consumption. Is 5% of the building’s heating bill more than double pane windows for one suite?
Sometimes a relatively easy solution is available in the marginal suites. Often there is 20ft of baseboard heating cabinet but only 10ft of actual heating tube inside. More fin tube can be added to increase the heat to a comfortable level often without raising the temperature of the water in the radiator.
Matching the people and building with correct control strategy, is where art meets science in application. Practical experience completes the formula for fuel savings and comfort in your buildings.