Heat Pumps: Efficiency, Insulation, and Ventilation

Jun 21, 2024 | General News

Heat pumps, running on electricity, are a viable option for heating homes. However, their efficiency and cost-effectiveness are significantly influenced by the level of insulation in the house. This brings us to the principle of “fabric first” – emphasising the importance of improving the building’s fabric before installing a heat pump. Proper ventilation is also crucial to ensure a healthy and comfortable living environment.

It’s essential for users to consider their heating costs on an annual basis. While there might be some high-cost days, the overall cost of running a heat pump should be viewed over the entire year. A fixed tariff can help stabilise expenses, balancing higher winter costs with lower summer bills.

To help customers reduce their energy bills, it’s crucial to minimise heat loss through effective insulation measures. The impact of these improvements is now easier to quantify with advanced technology, making investments in energy efficiency more appealing.

A proficient heat pump installer aims for the highest Coefficient of Performance (COP). Engaging customers in this goal from the beginning ensures better outcomes.

Demonstrating the Benefits of Insulation

To highlight the benefits of insulation on heat pump performance, we used an app to compare heat loss surveys for a property with varying insulation levels. The app functionality provides a clear picture of potential savings from insulation.

For instance, adding basic loft and floor insulation to a four-bedroom house with a total floor area of just over 200m² reduced heat loss by 45%, saving approximately £1,000 annually in fuel costs.

Heat Loss Calculations

Uninsulated House:

  • No floor or loft insulation.
  • Heat loss: 16,420 W.
  • Annual consumption: 36,100 kWh.
  • Cost: £3,094.28/year (assuming electricity costs 30p/kWh and COP 3.5).

Floor Insulation Only:

  • 150 mm PIR floor insulation.
  • Heat loss: 15,029 W.
  • Annual consumption: 32,506 kWh.
  • Cost: £2,786.23/year.

Floor and Loft Insulation:

  • 150 mm PIR floor insulation + 300 mm mineral wool loft insulation.
  • Heat loss: 9,258 W.
  • Annual consumption: 20,045 kWh.
  • Cost: £1,781.10/year (COP 3.5) or £1,503.38/year (COP 4).

The Importance of Fabric First

Renovating a house starting with insulation can halve heating costs. For example, a house with an old gas boiler operating at 80% efficiency would cost £3,158.75 a year to heat. Replacing the boiler with a heat pump without insulation would still result in high costs. However, adding floor and loft insulation significantly reduces these costs.

Installing insulation first also prevents problems associated with oversized heat pumps and pipework, such as increased short cycling, excess energy consumption, and reduced equipment lifespan. This approach leads to lower costs and better performance.

While the initial cost of insulation can be high, it’s a one-time expense with lasting benefits in reduced running costs. Grants like the Great British Insulation Scheme and ECO4 are available for low-income households, covering energy efficiency improvements alongside heat pump upgrades.

At Westville, we prioritise the best possible outcome, explaining the savings from a fabric first approach. This results in happier customers with warmer, more efficient homes. This approach is beneficial for all homes, regardless of the heating system used.

To learn more about how Westville can help you make the most of your heat pump installation, contact [email protected] or fill out the form below.