Regional Winners

Please tell us about a project you are particularly proud of – what was the problem and how did you solve it for the customer?

The customer had a solar PV and battery system and wanted to reduce his energy consumption to become as efficient and off-grid as possible. The customer wanted a heat pump/sustainable installation and I advised him on the best units for the job and created the design, including the custom-designed cylinder.

This is a 5kw Vaillant arotherm plus air source heat pump installation, with a custom-built 200ltr newark cylinder which I created with adam from heatgeek to increase the efficiency of the hot water cycle and improve the overall scope and performance of the heat pump. Some features we added include 2 x3mtr coils running parallel internally and baffles on the cold to stop destratification. Firstly, I started with a full house heat loss calculation, as I do with every job, but this house had a strange feature of poured concrete for internal walls.

I calculated room by room heat loss and an overall heat loss of 4.7kw, and this gave me the necessary information to design the system for a 5kw unit. I know I need to run dt5 for a heat pump system and calculate using mass flow. The unit needs 860l/ph and a flow temperature of 40c or a MWt-AT of 17.5c. This would allow me to get an MCS scop rating of 4.13 or an estimated performance of 413%. This job was actually also my MCS audit for MCS approval.

With a full radiator upgrade to allow for lower flow temperatures and a quicker flow rate 860 l/ph due to dt 5, we also did a full pipe design and some upgrades to allow for a fully open loop system and allow the whole system to run of a singular pump, utilising the remaining head of 40kpa in the heat pump and aiming for the pump to run and max 60-70% to maximize the running performance of the heat pump. We also added a full open energy monitoring kit, which can be seen on the heat pump monitor currently running a scop of 5 (10/02/24). A full system swap from a combination boiler to an unvented cylinder in a small cupboard needed some careful planning to allow room for all components and insulation.

Externally we used 140mm trunking with all primary pipework fully insulated and primary pro insulation for exposed external uv protection and sealed to stop any water ingress.

We then did a full system flush and refilled and re-circulated through a va14 demineralisation machine so we could  bring conductivity/hardness down in the system. Water System parameters are conductivity 70us, ph 8, hardness 0, iron 0, inhibitor 0. This allows us to test water quality every year on service and a chemical free system set up. We also commissioned on a Senso comfort control on priority domestic hot water, utilising pure weather compensation on a curve of 0.5 which is currently maintaining the house at a comfortable 20c internally,

just using the outside sensor to adjust flow temperature. The customer is utilising the off peak tariff to load batteries and then uses the solar and batteries to run the heat pump to gain even cheaper energy bills and efficiencies in the property.

Which products did you select for the job and why?

I used a 5 kw Vaillant arotherm plus for this job because of its great performance and great customer usability but also its versatility for ease of installation. I used a custom built newark 200ltr cylinder to increase hot water performance and overall heat pump efficiency. We installed all pipework in copper and press fitting and lagged with 19-13mm rubiflex lagging  for performance, a clean installation and to minimise energy losses. External pipework was primary pro with their bond and seal to maintain efficiency and stop energy losses We used a fernox antifreeze valve externally to protect unit from any possible freezing damage. This was paired with Senso comfort controls for weather compensation, bringing ease of use for the customer and in order to maintain a high heat pump efficiency.

We used a full open energy monitoring kit to give the customer our guarantee and accountability for high efficiencies and high scops. I also used a magnetic inline filter ball to protect the heat pump heat exchanger and a imi deaerator to remove any excess air to maintain high water quality. I used the thorough flush to flush system and a elexion va14 to demineralisation machine for a chemical free high quality system water.

Tell us what was different or unique about this job? Why does it stand out?

This job was difficult for me mainly due to this being the job I chose for my MCS audit so I knew I had to make sure the design and installation and all the paperwork was on point.

But it was also important to make sure the customer had the highest quality installation that gave him huge energy savings and high efficiency over the gas boiler he had previously installed, that would allow him to utilise his solar PV and batteries, go fully electric, and have his gas meter removed. So, the system design, heat loss and installation all had to be calculated correctly, along with the open energy monitor looking at all aspects of the install, it had to be correct as it records electric use, energy generated, flow and return temperatures and external and internal temps. In addition, the house was a unique build with the poured concrete internal walls, which actually allowed for a solid thermal mass and low heat loss. This job took one day on-site for heat loss and design, and five days on-site to complete the full installation.

And finally, tell us what the end result was for your customer?

The end result for the customer as of the date writing (10/02/24) is that he’s running his heat pump at a scop of 5. He has used in the last week 69 kw/h of electricity whilst actually utilising low tariff and running of solar or battery storage.

Using just 69kw/h of electricity, he has generated 344kw/h of heat for his heating and domestic hot water. So he has a huge saving compared to his old vaillant gas boiler. I have passed my MCS audit with the inspector being very happy with all aspects of the installation and the paperwork and designs. I am also very happy with the custom hot water cylinder we designed as it was running a daily cycle of 4.2- 4.5cop loading the tank to 55 c.

The system was maintaining a comfortable 20c indoor temperature on a 0.55 curve 40c @-3 with no internal reference or third party controls. The customer is extremely happy with the end result and lower energy bills and being able to be fully electric.