What do you think would be the best way for governments to facilitate an increase in the average energy efficiency of heat pump water heaters? Specific draw off tests, removing the element, tank heat loss, tariff consideration & implementation of timers.
What do you think would be the best way for governments to facilitate an increase in the average energy efficiency of heat pump water heaters?
There are a number of steps that could be implemented to ensure an overall higher efficiency for heat pumps.
– Incorporate a draw off test into AS/NZS5125:2010 to determine a systems capability of meeting load requirements more accurately. This is especially important in relation to heat pumps that contain an electric boosting element. Systems with boosting elements that are unable to meet load requirements, will switch to external heating far more often, reducing overall efficiency dramatically. There is some doubt hanging over current load profiles as they tend to spread usage across the entire day, whereas most household usage is focused on a couple of hours in the morning and evening. Future developments should look at removing the need for an element altogether. Introduction of Class A testing and ensuring the products perform to their specification and warranties. This will ensure the energy efficiency of the units.
– Adopt the same minimum MEPS standard for tank heat loss as applied to electric storage water heaters. To the best of my knowledge all current heat pump water heaters sold in Australia utilize a tank storage system. Standby heat loss accounts for up to 20% of daily energy usage, therefore any efforts to increase the thermo retention of these storage tanks would benefit overall system efficiency.
– Incorporate tighter controls on tariff connections to ensure that systems modeled for efficiency under different tariff supplies are being installed accordingly. This could include the addition of new markings on the unit that clearly indicate which tariffs are suitable to connect too. This would ensure that the estimated energy savings as determined by TRYNS modeling would, more accurately reflect the corresponding energy abate in the field. Future developments could see the introduction of a hot water/ heat pump specific tariff that benefits a household for investing in energy efficient water heaters and banishes the confusion between tariffs.
– Promote the use of timers in the design of Heat Pump controls. Timers can increase efficiency by allowing the system to function in day time hours when ambient temperatures are higher and the efficiency is greater. Timers also allow the systems to be better integrated into new smart grids, thereby reducing the peak loading and running costs when systems are connected to TOU basis.
By Simon Baird