Home
Case Study: Underfloor Heating and Ceiling Cooling

Case Study: Underfloor Heating and Ceiling Cooling

Installing domestic hot and cold services with Underfloor Heating and Ceiling Cooling

Already working with Multipipe for the underfloor heating system and domestic hot and cold services for the build, Excelsior Heating Services asked if we could also help with the cooling system, as they had no previous experience in it.

Because it is well insulated and has a lot of glass, one of the challenges was the heating in the building. The client’s consultant wanted to use cooling via the heat pump system, and the original design for the cooling involved using ceiling panels and wall panels. We suggested it would be better to install the system directly into the fabric of the building and plaster it in to give it a true thermal mass.

Project at a glance:

Executive home
Ground and second floor
Combined area 823sqm
Domestic hot and cold services
UFH heating system throughout
Cooling system in ceilings
Pumpstations

“After working with Multipipe for this project, it has made us far more confident to move forward on other projects, specifically with cooling. The support I’ve always had through ordering, design, and supply from Multipipe has been amazing.” – Matthew Smyth Excelsior Heating Services Ltd

Read the full case study here.

Home
Secondary Recirculation Systems

Secondary Recirculation Systems

Why You Should Use Secondary Recirculation Systems

As houses get bigger and clients demand even more from their installer, one of the biggest issues is delivering hot water quickly and efficiently to the hot water taps. The only way to efficiently do this is by setting up a circulation loop from the cylinder to the tap emanating the dead leg between the two – known as a secondary recirculation system. Although there are no legal requirements to fit one, HSE’s best practice is to deliver 50°C water within 1 minute to a tap; this is for legionnaire control.

How Does a Recirculation System Work?

The idea is you have your primary hot water pipe flowing through your house. Besides this, you have a “secondary recirculation pipe”, which travels beside the hot water primary pipe to the extremities of the system. The secondary pipe taps into the primary to join the two pipes. The cylinder then has a hot water circulation pump (normal heating system pumps will not work). The pump is set to push the water through the primary pipe to the tap, and it then returns on the secondary pipe, thereby keeping your hot water hot all the way to the tap.

Limits of a Secondary System

With 60-70°c water flowing through it for most of the day, the secondary pipe has a hard life. A heating system can flush through the water’s pH and impurities. However, you cannot do this with a recirculation water system. Also, you are transporting oxygenated water, which can harm parts of a system. This is why all plastic pipes made under BS 7291 cannot be used on these systems. However, because of how our pipework is made, MLCP can be used with recirculation systems as Multipipe MLCP is made to a different standard than plastic pipe. See our MLCP range here

Our Top Recommendations for Secondary Recirculation Systems

Where possible, insulate as much of the pipe with good quality, thick insulation. This will limit the heat loss going back to the cylinder.
Only use a WRAS-approved pump specifically designed for hot water circulation.
Fitting a timer to the pump is a great idea for energy efficiency to stop the circulation when not needed.
You can use a rule of thumb of 2 sizes smaller than the flow pipe for sizing the right pipe.
If you have reduced flow rates at your tap, you might need to fit a flow restrictor on the secondary pipe to push water to the tap.

Towel Rails

Did you know fitting a towel rail on the secondary circuit can be done? This is great because they keep constantly hot! (as long as the timer runs). Ensure you consider the heat loss to your cylinder, but also, they *MUST* be WRAS approved and made of stainless steel or copper. Lastly, the towel rail should only be fitted to the return circuit of the hot water system.

If you have any questions about secondary recirculation systems, please email our technical team who will be happy to help: [email protected].

Home
Do You Install Your Hot and Cold Pipes in Floors?

Do You Install Your Hot and Cold Pipes in Floors?

Most of you know the water regulation schedule, a government set document that lays out rules for installing (and manufacturing) pipes and fittings. In this article, I’ll look at one small paragraph: Schedule 2, section 7 under the heading of “Requirements for water fittings” to explain how you can install your hot and cold pipes in floors.

I have often seen and spoken to people about pipework in floors. However, when it comes to space heating (underfloor/rads etc.), it does not directly affect this (WRAS does not cover heating services). Still, I consider it good practice to adopt the principles of this regulation for radiators etc.

However, we should be more concerned about potable water (hot and cold-water supplies) as this water regulation is enforceable by law. Failure to meet these standards can result in fines or imprisonment, so ensure you read this carefully when embedding pipes and fittings in a wall or floor.

Ensuring You’re Regulation Compliant

I created this article to share my biggest concern surrounding what I see as a lack of awareness. One day, I mentioned the water regulation to a college lecturer and found he was not aware of it. This example may have been an isolated case, but standards will slip if we are not teaching the new plumbers of this world.

WRAS has made a convenient guide to break down the entire section of the regulations, so it is well worth reading (you can find the link below this article). First, however, I’ve broken down the key points you need to consider when laying a hot and cold system on a screed floor.

‘No water fitting shall be embedded in any wall or solid floor.’

Clarification:

“water fitting” – this refers to any fitting and includes the pipe.

“Embedded” – this means in direct contact with the screed or plaster.

To conform to this rule, we recommend that you either look at the installation of a manifold plumbing system, or you must look at boxing in any fittings under the floor, and this must then be accessible. As for the pipe, we recommend that you look at our pipe-in-pipe solution or sleeving the pipe yourself. Either way, the pipe should be free to be pulled out and replaced without having to dig up the screed.

Underfloor Heating Systems

NOTE: the pipe should sit above the insulation board to stop the risk of freezing. However, if you are to install a UFH system, the pipe in the pipe should be cut into the insulation board. The pipe should then be covered with an additional 25mm insulation layer to stop the risk of overheating the cold-water pipe.

No fitting designed to be operated or maintained, whether manually or electronically, or which consists of a joint, shall be a concealed water fitting. This rule means any valves or used devices (stop cock etc.) should not be covered. So, where you have valves in a wall or floor, they need to be boxed and have an accessible door).

‘Any concealed water fitting or mechanical backflow prevention device, not being a terminal fitting, shall be made of gunmetal or another material resistant to dezincification.’

All our fittings are made from a DZR material or come tin-plated. This method is to ensure that dezincification cannot happen.

If you’ve any more questions about installing hot and cold pipes in floors, our technical team are always here to help you out.

Ref: https://www.legislation.gov.uk/uksi/1999/1148/schedule/2/made
Ref: https://www.waterregsuk.co.uk/downloads/public_area/guidance/publications/general/info_leaflets/para_7_guidance_version_2_july_2014.pdf