Remeha sets new standard for boiler size and weight

Remeha, Boilers, space heating
A single-piece cast-aluminium heat exchanger is the key to the small size and weight of Remeha’s Gas 220 Ace boiler.

Floor-standing boilers have just got a whole lot smaller with a new launch by Remeha. Ken Sharpe was invited to Holland to find out more.

The size and weight of boilers have been shrinking by leaps and bounds for many years — one could even say many decades. One of the main driving forces is the move from cast-iron sections for heat exchangers to materials such as stainless steel and aluminium, combined with smaller waterways.

So great has been the reduction in size and weight that wall-hung boilers account for the majority of the market for commercial boilers, often operating in cascade arrangements to deliver high outputs with a large turndown ratio.

At the top end of outputs for wall-hung boilers is the 160 kW from Remeha’s Quinta Ace 160 boiler introduced in the middle of 2016. These boilers can be installed in cascades of up to eight to give a total output of 1.28 MW, modulating down to 32 kW — 20% of the maximum output of a single boiler in the cascade.

But there remains a significant demand for floor-standing boilers. Here, too, however, there is pressure from the market to reduce their footprint in response to ever-more restricted space in plant rooms — as was revealed by a market survey carried out by Remeha about five years ago.

The findings of that survey were fed into the company’s new-product development process, leading to the recent introduction of a floor-standing boiler that is substantially smaller and lighter than the company’s long-establish Gas 310 range.

In preparation for the comparison, a reminder that Gas 310 boilers with outputs of 261 and 327 kW (flow/return of 80/60°C) have a footprint of 2 m2 and weigh 364 and 398 kW, respectively.

The new Gas 220 Ace boilers all have a footprint of 0.87 m2, well under half the size of the Gas 310 models — albeit they are slightly higher because all connections (water, flue and gas) are conveniently on top of the boiler. The two largest Gas 220 Ace boilers weigh just 243 kg for outputs of 243 and 291 kW (same flow/return temperatures). There are two other boilers in the 220 range, having outputs of 160 and 220 kW, with the smallest boiler modulating down to 34.7 kW.

The key to the small size and weight of the new boilers is the heat exchanger — a single-piece stress-free casting of aluminium in various sizes depending on output. UK sales director James Porter observes, ‘A single-piece heat exchanger for an output of nearly 300 kW is no mean feat, as the R&D team will confirm.’

The Gas 220 range has a number of design features for ease of installation, servicing and combining several boilers into a cascade arrangement — side by side or back to back.

Servicing is carried out from the front of the boiler, with a clearance of a metre. There is even a light inside the boiler itself.

Also inside the boiler is the first stage of the flue, with built in tuned dampers to reduce noise.

Also built into the boiler is a flue non-return valve so that boilers can be flued together into a common flue header without the risk of flue gases entering the other boilers.

Remeha, Boilers, space heating
With all the connections at the top, Gas 220 Ace boilers can readily be cascaded using prefabricated rigs with a low-loss header.

The boilers are on wheels, with access to the condensate drain being from underneath with a simple click connection. There is no need for a plinth because the boiler is already raised so it is clear of the floor.

Time and temperature controls are supplied as standard, including built-in 0 to 10 V and volt-free contacts that can connect to any BMS without the need for additional parts.

Seasonal efficiency ranges from 95.5 to 95.9%, based on gross calorific value and depending on the model.

NOx emissions are to ErP Ecodesign (iii) 2018 and EN15502 Pt1 2015, Class 6 — so these boilers are eligible for full BREEAM credits and future proofed for regulations.

For ease of installation, these boilers will pass through a standard door, and they are delivered on a pallet with a built-in ramp, making them easy to offload.

Considerable installation and operating experience has been gained at a swimming pool near Remeha’s headquarters at Apeldoorn in Holland. Remeha regularly tests equipment here and provides heat for free in return. A Gas 220 boiler has been working here for about 18 months and is the longest-serving such boiler.

In the UK a Gas 220 boiler has replaced a Gas 210 Eco Pro at the Samuel Whitbread Academy in Shefford, Bedfordshire. Heating engineer Ashley Jones of Spa Gas comments, ‘A lot of thought has obviously gone into the packaging and pallet design to simplify and speed up installation.

‘Disconnecting the old Gas 210 Eco Pro, unpacking the new Gas 220 Ace and then positioning it in the plant room took just an hour and a half. I like the integrated wheels, which make it easier to manoeuvre the boiler into the final position.’

And Tristan Mitchell, facilities manager with Galliford Try, FM provider for the academy, is also taken by the boiler’s size,’ First impressions? It’s so compact!’

And in the world of boilers, size counts — the smaller the better.

For more information on this story, click here: June 2017, 70
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