SANCO2: The Clear Path To Net Zero Energy.
Multifamily DHW projects and the new 119-gallon tank
The efficiency of the SANCO2 is attractive for new multifamily projects but the offering of 43 and 83-gallon tanks are tough to fit into a building since space is tight. With a new 119-gallon tank things change. At the typical 149F water temperature, the 119-gallon tank can deliver about 158 gallons of 125F water. However, as you look deeper at the new G3 heat pump options you find the output temperature range is variable from 130F to 175F. By increasing the heat pump output temperature to its 175F maximum, the tank now is full of 175F water. The yield of the tank at 175F increases from 158 to 198 gallons. Now a single tank can serve 4-5 apartments. This approach significantly reduces cost and space required in multifamily building applications. It’s the new clean and efficient way to make the most of the new G3 heat pump and a tank that holds 36 extra gallons. By placing the buildings DHW system into smaller distributed plants serving nearby units, the internal heat gains resulting from long DHW recirculation runs are reduced resulting in less need for cooling and also getting the full use of the high COP from the CO2 refrigerant heat pump.
It’s a bit astounding that a 30% increase in tank volume and the ability to increase the output temperature of the heat pump will yield a 66% increase in delivered DHW. The DHW tank yield is calculated using three variables: 1) Heat pump output temperature, 2) Incoming water temperature from the cold water supply, 3) Mixing valve set temperature to the building occupants. Sanden has created a mixed water fraction chart covering all of the variables which can be used to calculate the DHW yield for any project. You can download the document here.
- 5x more efficient than traditional electric water heater
- Allows use of off-peak power
- Greater first hour rating than all heat pump water heaters
- Faster recovery after hot water draw
- Hot water production down to -20°F & below
- Up to 175°F delivered hot water temperature
The Sanden SANCO2™ Heat Pump Water Heater is a two-part system consisting of a tank (usually placed indoors) and a heat pump unit (usually placed outdoors, up to 50 ft away from the tank). The heat pump works like a reverse air-conditioner, drawing heat energy from the atmosphere and applying it to water in the tank. This technology is already in wide use in industrial applications as well as residential water heaters in countries like Japan and Australia.
The Sanden SANCO2™ works just like a conventional heat pump, except that it uses CO2 as a refrigerant. Due to the unique properties of CO2, the Sanden operates very efficiently in a wide range of temperatures. It is able to extract heat from the air all the way to -20°F and beyond It accomplishes this in a single heating stage, raising the water temp as high as 175°F at .3 gallons/minute. The result is a system that requires radically less electricity to heat water when compared to conventional hot water systems and works without a backup coil in a very wide range of climates.
While the Sanden system is a perfect choice to replace an existing gas or electric hot water tank in any residential or multifamily application, the ability to work at low exterior temperatures and still supply hot water at 175°F means the same system can be the total heat demand solution for today's new low energy homes.