Design to maximize the cost effectiveness of an ammonia heat pump.

The key barrier to wider use of heat pumps is cost effectiveness when compared to other forms of heating. Despite growing environmental concerns heat pump adoption is not growing as quickly as had been expected by many. Falls in the price of fossil fuels mean heat pump costs are likely to have to fall and / or efficiencies will have to rise before more users choose heat pumps. Large ammonia heat pumps can be cost effective and this paper will consider elements of the design of heat pumps that can enhance payback including providing guidance on cost effectiveness of extra heat exchangers and non standard arrangements. Control concepts are considered with regard to maximising the heat output and efficiency. Calculations of the performance across a range of heat outputs and operating conditions for a specific system are used to demonstrate the possible variations of different operating concepts.