There are a few things that set this design apart from the status quo;

• Hybrid closed and open loop
• Variable loop flowrate
• Heat exchanger backflush

All of this comes together to make a highly efficient and innovative installation.

Hybrid closed and open loop -

This site didn’t have the space to easily install a horizontal groundloop and vertical was cost prohibitive. The site had an existing shallow well, but when we tested the refresh rate it wasn’t high enough to reliably provided the water we would need for an open loop system. By incorporating a mechanical diverter valve, a portion of the water is returned to the well and a portion rejected. The long buried supply and return lines also draw a significant portion of their thermal energy from the trench.

Variable loop flowrate -

Design flow is a parameter that needs to be considered carefully, to deliver the manufacturers recommended flowrate is a good starting point, but we can improve on that even. Multi stage heat pumps are capable of modulating heat pump output, to optimize run time and COP. The result is a variable requirement for heat input – the heatpump requires more thermal energy in stage 2 than stage 1 for example. Since the energy available is a function of temperature and flowrate, and we can’t change the temperature – we optimize the flow to conserve energy.

Too much flow - With a relatively high head and long supply line open loop system, pumping energy can be significant with no gain. Excessive velocities can cause premature failure in system heat exchangers, valves and elbows.

Too little flow – Too little flow reduces operating COP and can even freeze the evaporator in heating.

Heat exchanger backflush -

Biofouling of open loop heat exchangers is a very real concern and raises the potential for increased maintenance and reduced performance. By reducing the flow direction in a heat exchanger periodically, we can eliminate the need for heat exchanger antiscaling service or replacement. This is accomplished automatically by using 2, 3 way diverter valves, driven in opposition automatically by schedule.

Program information

Response form

When the heating and cooling loads are similar, the heat pump(s) will maintain the hot and chilled buffer tanks. This essentially means that heat is moved from one location, to another within the same building. For example, domestic hot water can be heated with the heat extracted from a space requiring cooling.

When the loads are unbalanced (more heating or cooling required), a valve with direct flow to the geothermal field and start the field circulating pump(s). In this mode, heat can be extracted from or rejected to the field at a system COP (coefficient of performance) in the order of 4.

In this case, the geothermal field included a series of vertical boreholes to 300′.

This is great for that time you head off to work and realize that you left the thermostat on high…or heading home from work and realize you left it on low and want it toasty for your arrival. How about managing multiple thermostats remotely? maybe you are a property manager for churches, community centers, condo’s or school or maybe its a remote location that is visited sporadically like a cottage or summer home. But these are much more than a convenience and comfort device.

The bottom line is that these devices can make you more comfortable while saving energy. Another benefit is the cost monitoring – they can connect directly to your utility and display what you are paying for electricity – real time. This allows you to manage your heating and cooling effectively in a “time of day” electricity billing scenario.

Check out a few manufacturers;

Radio Thermostat

Ecobee

The control and distribution of a biomass gasification system can be every bit as comfortable, efficient and civilized as any other heating system.

Solar thermal fits seamlessly into this installation, providing nearly free energy for space heat or domestic hot water when it is available.

A 2 pipe per trench horizontal ground loop provides superb performance, minimal pumping power requirements and minimum pipe in the ground. It does however require more digging and more land, but provides excellent long term performance.

By utilizing an outdoor reset control strategy, we can provide more even heat to the spaces, reduce energy consumption and not overshoot or undershoot our heating set points.

Concealing the wiring and insulated lineset in a colour matched false downspout is just such a detail. By routing below grade where necessary in sealed piping allows a retrofit that can integrate seamlessly with any house design.

Stage 3 Renewables Inc. has been contracted to provide Engineering design, schematics, specifications and letters of assurance for the project.

Check back for updates as the project develops.