Is it possible to achieve large energy\nsavings with minimum capital investment, by using existing equipment to its\nfull potential? <\/p>\n\n\n\n
In 2018, Impact Engineering was engaged by\nMore Than a Roof Housing Society, to study its Sunset Towers facility, and to understand\nthe potential for building recommissioning to achieve energy savings. <\/p>\n\n\n\n
With Study and Capital funding from the\nFortisBC Custom program as well as BC Housing\u2019s EERP program, Impact achieved a\nmeasured 25% reduction<\/strong> in natural gas use, resulting in a simple\npayback under 2 years<\/strong> after Fortis incentives.<\/p>\n\n\n\n This is the story of how thoughtful\ntargeted actions lead to approximate savings of 50% in base energy use\n(primarily DHW) and 10% in heating related energy use.<\/p>\n\n\n\n Sunset Towers, located in Vancouver, BC,\nconsists of two towers (16 storey, 23 storey) covering a total of 150,000 ft2<\/sup>\nof conditioned space. The buildings are heated by a central mechanical plant\nsupplying hot water to radiators, to rooftop ventilation units and to heat\nexchangers for production of domestic hot water.<\/p>\n\n\n\n At the heart of the plant are five (5) 1,500\nMBH condensing boilers. <\/p>\n\n\n\n At Impact, our design philosophy is centered\non uncomplicated systems, which are easy to operate and to maintain. On our\nfirst site visit to Sunset Towers, we realized that though the main equipment\nwas high efficiency, the complexity of the existing plant did not facilitate\nefficient operation.<\/p>\n\n\n\n It was also clear upon review and in\nspeaking with the maintenance contractor that the building DDC system had\nfailed to perform its function. As a result, manual adjustment was necessary.<\/p>\n\n\n\n The combination of these factors was\npreventing mechanical equipment from achieving its high efficiency potential.<\/p>\n\n\n\n The first step to unlocking the energy\nsavings potential was the physical piping separation of DHW and space heating. This\neliminated a complex control valve arrangement and allowed boilers to match demand.\n<\/p>\n\n\n\n Two (2) boilers now serve DHW and three (3)\nserve space heating, providing redundancy for each system. Manual shut-off\nvalves were installed to enable reconnection of the entire plant if needed.<\/p>\n\n\n\n A new DCC control system was installed,\nwhich allowed space heating boilers to follow an outdoor air temperature reset\ncurve. Ventilation supply temperature also follows an outdoor reset curve and\nair volume is adjusted seasonally.<\/p>\n\n\n\n Rather than store DHW at continually\nelevated temperatures, a Cleanse Mode was programmed to allow the DHW boilers\nto operate in their highest efficiency range.<\/p>\n\n\n\n The DHW\nboiler circulation pumps were replaced with smart pumps to respond to actual\nDHW demand and DHW storage was reduced from (3) tanks per zone to one (1) tank\nper zone.<\/p>\n\n\n\n DHW\nrecirc pumps were disabled from 11pm \u2013 6am and only activated during\noperational hours when the recirc temperature drops below a setpoint.<\/p>\n\n\n\n Existing zone thermostats consisted of\nmanual lever arm models that were inaccurate and were often set for\ntemperatures as high as 30\u00b0C with windows left open to combat overheating.<\/p>\n\n\n\n These controls were replaced with digital\nbattery-operated thermostats with pre-programmed temperature range limits. <\/p>\n\n\n\n In the first year of operation post\nretrofit, Sunset Towers saved more than 4,000 GJ and over 200 tonnes of carbon emissions.\n<\/p>\n\n\n\n Our monitoring has shown that most of these\nsavings (almost 50%) came from the base load (primarily DHW). All the actions\ndescribed above made this possible. <\/p>\n\n\n\n Additional space heating savings are\npossible beyond the current 8% reduction. We plan to further optimize this\nsystem by reviewing DDC logs for opportunities to match loads as closely as\npossible. <\/p>\n\n\n\n This experience makes it clear that there\nare substantial energy savings waiting to be unlocked in existing buildings and\nthat these savings do not require substantial investment in new equipment. <\/p>\n\n\n\n Owners and Operators have a fantastic opportunity to realize this value.<\/p>\n\n\n\n —<\/p>\n\n\n\n If you\u2019d like to chat about recommissioning\nand simple energy strategies, contact us anytime.<\/p>\n","protected":false},"excerpt":{"rendered":" Is it possible to achieve large energy savings with minimum capital investment, by using existing equipment to its full potential? In 2018, Impact Engineering was engaged by More Than a Roof Housing Society, to study its Sunset Towers facility, and […]<\/p>\n","protected":false},"author":6,"featured_media":7069,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[74],"tags":[],"yoast_head":"\nBuilding Systems<\/strong><\/h3>\n\n\n\n
First Impressions<\/strong><\/h3>\n\n\n\n
Energy Saving Strategies<\/strong><\/h3>\n\n\n\n
Decoupling Domestic Hot Water from Space Heating<\/strong><\/h4>\n\n\n\n
Boilers System controls with DDC<\/strong><\/h4>\n\n\n\n
DHW System Improvements<\/strong><\/h4>\n\n\n\n
Zone Control System<\/strong><\/h4>\n\n\n\n
Following the Savings<\/strong><\/h3>\n\n\n\n
Opportunities Abound<\/strong><\/h3>\n\n\n\n