What We Do

Our services include:

Deep Lake Water Cooling

District Heating

Energy Management Services

Frequently Asked DLWC Questions:

1. Does Enwave’s DLWC system warm up Lake Ontario? The Deep Lake Water Cooling (DLWC) process starts on the south side of Toronto Island at the City run Island Filtration Plant (IFP). It is here that the City draws in lake water to filter and chlorinate for potable water consumption throughout Toronto. The clean drinking water is sent under the Inner Harbour to the City’s John Street Pumping Station (JSPS) where very large pumps send the drinking water out to reservoirs and water towers. Before the cold potable water leaves the JSPS, it passes through a very large bank of heat exchangers where the heat energy from Enwave’s cooling customers is transferred to the potable water supply, without the two fluids ever coming into contact. Enwave’s warm water returns from our customers, is cooled down in the heat exchangers by rejecting heat into the City’s cold water supply, and returns to our customer sites much cooler.
   
   The warmer drinking water continues on to reservoirs, and ultimately to our homes and offices where we drink, cook and clean with domestic water. This warmer water is then treated at the City run Sewage Treatment Plants where the temperature is tempered down to an acceptable level before being released back into Lake Ontario.


2. How much does it cost to connect a building to Enwave’s DLWC? The cost to connect a building to Enwave’s Deep Lake Water Cooling system varies depending on the location of the building in relation to our distribution network. The majority of Enwave’s 48” diameter chilled water supply and return pipes are buried in tunnels between 60’ and 120’ below the streets of Toronto. Connection costs heavily depend on the work required to get pipes from our distribution tunnels, up to the building’s foundation, and through the wall of the building.
   
   Additional costs are incurred inside the building to install heat exchangers, run pipework from Enwave’s chilled water pipes from the building wall to the exchangers, and finally connecting the exchangers to the existing chilled water system in the building.
   
   All of this construction can be considered connection costs, and because of all the variables, Enwave performs a detailed analysis in the building to arrive at connection costs that are presented to a customer in a DLWC proposal.


3. How much do buildings save on DLWC? As explained above, no two buildings incur the same connection costs. Because of this, the ultimate operational cost of DLWC in a building can only be compared to the cost to install and run chillers in the same building. Buildings that are easier to connect to Enwave’s system may experience operational cost savings; however this is not always the case.
   
   Enwave cooling customers will experience significant savings in electrical consumption and demand charges, water consumption for cooling tower use, and chemical treatment in the building’s condenser water loop


4. Can Enwave’s DLWC be connected to a residence in Toronto? Unfortunately the cost to connect residential buildings would be many times the cost of the installation and operation of today’s newer air conditioners. The cost involved in extending the service from Enwave’s distribution tunnels to the residence would be prohibitive.



5. Does a building use DLWC during the winter? A large number of office buildings do require cooling throughout the winter. While the majority of cooling requirements during summer months are comfort cooling for tenants, there is a small cooling component required year round for small server rooms, elevator machine rooms and mechanical rooms where any heat build-up might damage sensitive equipment.


6. Is Enwave draining the lake? As explained in Question #1, the interconnection between Enwave’s DLWC system, and the City’s Potable Water system, Enwave never dictates how much water is drawn out of Lake Ontario at any given time. The flow of water is completely dependant on the demand for potable water by the City’s residents, not Enwave’s cooling system.
   
   During winter months when cooling demand is low, Enwave only uses about 25% of the cold water treated at the Island Filtration Plant. During hot summer days, the City water flow through Enwave’s heat exchangers approaches 100% of the potable water produced at the IFP.
   
   Because Toronto Water manages the volume of water drawn out of the Lake, they can ensure that the amount of water released out of Sewage Treatment Plants is the same as the amount of water drawn out of the Lake at Water Treatment Plants.


7. How does DLWC reduce the strain on the electricity grid? The majority of Enwave’s cooling load is proportional to the ambient temperature outside. This means that customers demand more cooling as the weather gets hotter. Customers that have switched to Enwave DLWC are now using a clean, green, renewable source of cooling that unlike conventional chillers, does not rely on electrical consumption. The result of this switch from chiller use to Enwave cooling is an overall reduction of 61MW of electrical demand on Ontario’s electricity grid.
   
   The time of year that this peak reduction occurs is very important for the province, as our electricity grid is constrained the most on the hottest summer days. The same days that Enwave’s reduction contribution is maximized.