Page 21 - PDZA Sustainable Aquarium Brochure

HEATING AND COOLING

There are other energy recovery strategies such Referring back to the annual heating and cooling
as enthalpy wheels, which can provide much energy charts and including the heat recovered
higher energy recovery rates, ranging from 70% from the exhaust air, we can see additional time
to 85%. However, they come with risk of cross each year where we are benefiting from the higher
contamination between the exhaust and outside efficiency of using the exhaust air stream as a heat
air intake streams. For this project, we are using source rather than ambient air. (See Figure 7).
the chilled water loop and our heat pump’s ability
to move energy from the cooling to the heating Pulling the whole concept together in a schematic
loop to actively recover energy from the exhaust air diagram (see Figure 8), we can see how the air
stream. That provides a significant improvement in source heat pump plays a central role in managing
heat recovery efficiency. An “active” heat recovery the heat sharing and transfer from the exhaust air
strategy places a heat recovery cooling coil in heat recovery to the exhibit tanks, and any space
the exhaust air handling unit, and is designed to within the building.
remove heat from the exhaust air before it leaves
the building (see Figure 6). This heat energy
travels back to the air source heat pump where,
internally within the heat pump unit, the heat
energy is transferred from the chilled water loop
to the heating water loop. The calculated heat
recovery efficiency is 94%, which is at the high
end of heat recovery systems normally ranging in
efficiency from 50% to 90%.

Figure 6—Heat Pump Heat Recovery Schematic

CASE STUDY: THE PACIFIC SEAS AQUARIUM AT POINT DEFIANCE ZOO & AQUARIUM 21