Regional Winner

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 client of this new build dormer bungalow asked me to design and install a heating system that would provide a comfortable room temperature whilst being as cheap as possible to run.

The client requested to use natural gas as the method of heating due to the connection already being in place. This was difficult for me to hear as I am committed to being sustainable and believe in the long-term benefits. After long discussions, we compromised on designing the system to a super low temperature and added hybrid solar thermal panels to the installation. These are for hot water and heating and will offset the gas usage. The roof had been slated by the time I came to first fix, so I had to work closely with the roofers to explain the positioning and set up of the panels. I supplied technical guidance.

Underfloor heating was installed at 100mm centres, keeping the flow temperature super low and comfortable. This design is the open loop approach and controlled by pure weather compensation.

Radiators installed on the first floor have been designed at 35°c flow at -3 outside temperature. I was able to reduce the flow temperature by spending time with the calculation software, enabling me to size the radiators correctly to be most efficient. Part L minimum requirements were improved. I had continuous input from the client and builders to ensure that insulation levels were high. Both the ground and first floor have been designed to work on open loop weather compensated controls.

I have learnt that you cannot always change people’s minds when renewable technology is involved. However, I feel that I was able to put across the information and we compromised with other technology. I have also learnt to liaise with the whole team and provide reassurance and guidance when new products are used which they may not have experience with (and would be happier sticking to what they know!).

I am very proud that I was asked by the client to install and oversee this build. Many local tradesmen have been into the build and have commented on the installation.

Which products did you select for the job and why?

The whole system has been designed to be heat pump ready. The boiler I chose was the Viessmann 200-w, largely due to its impressive control and ability to modulate its power to 1:17. This is very similar to how a heat pump would modulate. This boiler is a four pipe boiler which gives priority hot water. This boiler has good reliability, build quality and come hydrogen blend ready.

The heart of the installation lies in the 4 ABORA hybrid solar panels located on the roof. These prioritise hot water and then switch over to heating the buffer tank. ABORA manufactures the most efficient hybrid solar panels in the world, with an overall efficiency of 89% This was a major factor in me choosing these panels. The gas boiler will only be used as a last resort. A bonus is that the panels will also produce electricity to help offset house running costs.

I have used 2 twin coil Joule unvented indirect cylinders in this system. Both are high gain cylinders which are compatible with a heat pump. They provide better heat recovery, due to the coil design/size. One cylinder provides hot water with input from the solar thermal panels and Viessmann boiler. The other cylinder is used as the heating buffer, also with input from the panels and boiler. I have utilised this cylinder to use one coil to preheat the cold feed into the hot water tank. This means that the water entering the hot water cylinder will need less energy to maintain the cylinder at 45°, therefore keeping the boiler as efficient as possible. Stratification will be more even. I have designed the system so that the boiler is always condensing and wastes the minimum amount of energy to the atmosphere. A programmer has been installed to provide a weekly anti-legionella cycle.

All radiators are fed by an Uponor central manifold. This is so that I can set the flow rates as needed to provide the correct output. This manifold is of high quality and spare parts are readily available, should they be needed.

The buffer cylinder feeds 2 mixer pump groups made by MeiFlow. These are independently controlled with 2 heat curves. One mixer is dedicated to the underfloor heating and the other to the first-floor radiator circuit. I chose these as they offer a compact, fully insulated pump group that looks professional.

I discussed the design with our local plumbing merchant. Unfortunately, due to the bespoke nature of the project, I was unable to buy many of the components with them. I ended up using some of my trusted suppliers from further afield who I have worked with before.

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

The job was totally unique as I used the equipment differently from its original intended use.

As a rule, I install underfloor heating at 100mm centres, whereas my local competitors use a minimum of 150mm centres. If I followed their model, I would save time and work, but I strongly believe in reducing flow temperatures and the gains you get from this is substantial e.g. cost and efficiency. This project alone has nearly 1.5 miles of underfloor pipe.

The hybrid panels are uncommon in our region as they do not tend to be installed and are not known about. Traditionally panels are used for hot water production but I have utilised them for the heating system as well. I believe this is a very under-used form of energy.

I like to try new products and am willing to learn from other amazing installers who have used them before me. I feel that I have learnt a lot from attending the annual installer show, and the networking opportunities have brought me closer to various products that I may not have considered otherwise.

I also believe that pre heating the cold water through the buffer will increase efficiency. By supplying the hot water cylinder with a warmer feed, the depletion of hot water will be slower and recovery times should be improved. Water can be stored at a cooler temperature to reduce standing heat loss and reduce energy consumption.

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

This client made it clear that the initial installation cost was not an issue. They were interested in keeping running cost down and comfort levels high due to it being their forever home.

On a previous project, I have installed 2 solar thermal panels on a client’s roof. The feedback I have been given is that they only use the heat pump for approximately 20-30% of the year. The UK supplier of the hybrid panels has estimated that these 4 panels on the current client’s roof will provide the majority of the house energy needs.

The client has been very happy with the quality of the workmanship and equipment installed. They have been impressed with the high performing, low maintenance heating system and show everyone into the boiler room on a tour of the house!