Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
 Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




Heating and cooling: UFH below kitchen cabinets

Bottom of Page

1 to 15 of 15

  1.  
    • CommentAuthorluz13827
    • CommentTimeOct 29th 2021
     
    We are planning for wet underfloor heating in our renovation project (if anyone has any brand recommendations, please do share!) - my question is regarding whether or not to place the underfloor heating below kitchen cabinets.

    I think often people don't put UFH under cabinets because it could be a waste of energy in those areas, but is there any risk to the cabinets themselves? Or any appliances we should not have UFH below, e.g. the fridge/freezer?

    The reason why I am considering having the UFH below, is that the kitchen cabinets will partly back onto an external wall, and so I think UFH would make sense as otherwise that wall would could potentially not get as warm, and could then lead to condensation behind the kitchen units, that we can't see. Does that make sense? We are of course doing everything possible to manage humidity in the home to limit the chance of this in the first place, but I'm thinking worst case scenario, if RH did rise. We have had mould issues in the past, so trying to avoid that at all costs.
    • CommentAuthorrevor
    • CommentTimeOct 29th 2021
     
    I would not worry. It is wise to have heating close to the wall and the cabinets nor content will be affected. Fridges freezers dishwashers etc will generate more heat. If you are concerned about flow of air you could put a couple of grills to ventilate. We took our plinths off the other day to have a look and all was fine.
    I had my system from Robbens was very impressed with them. Send in plans and they do a layout pipe spacing etc make up and test the manifold mounted on a board labelled up with loop name flow rate ready to mount on the wall and connect up to. You need to tell them what your heat source will be HP or boiler as the manifolds and pipe layouts are designed accordingly. You can get a complete kit including the stats and a hub to connect to a portal where you can view and control your system on a smart phone or pc. I bought my system about 6 years ago so specs will have changed and I am sure there will be other systems out there. Selling point for me was the quality of the materials used.
  3.  
    We didn't put heating under our units. On the negative side, it would have increased the surface area and heated the junction of the wall and floor. On the positive side, it probably keeps dried food etc in the units a little cooler.

    Our units are on legs, so there is plenty of ventilation underneath and it's also easier to clean if there is a leak or whatever. So UFH probably wouldn't have been much of a problem.
    • CommentAuthorrevor
    • CommentTimeNov 3rd 2021
     
    Another thing to consider if you remodel the house later then you will have a missing bit of heating where the cabinets used to be. Not having heating up to the wall means you will be drawing heat from the rest of the floor through the slab. Many heating loop designs have pipes closer together near external walls to compensate for heat loss. In our previous house we only had radiators and cooking oil kept in bottom cupboards next to external wall would solidify in winter. So I would vote in favour of heating whole floor. However if you are going to get someone to specify the system then see what they say.
  5.  
    We have done the whole floor area in the last 3 projects. In case of future rearrangement.
    Pipes closer together in the external doorways, and in the one full-height window in the current project (it was a doorway)
    I like to think the whole slab will be the same temperature and ideally the whole house the same temperature.
  6.  
    Posted By: luz13827the kitchen cabinets will partly back onto an external wall
    I can't add about the UFH, but I slid sheets of foil PIR insulation up into the gap behind the back of our kitchen cupboards, and in the gap underneath the cupboards. This has raised the temperature of the cupboards and cured previous condensation problems that we'd had, like others described.

    I was a bit concerned about condensation forming behind the PIR instead, but took some out after a year and found no sign.

    It also increased the path length for heat to escape from the kitchen through the ground to outside, so has made the floor warmer. This isn't relevant for Luz who will have insulation and a toasty floor anyway!

    Longer term we are looking at UFH retrofit, but the exposed floor area of the kitchen is relatively small due to the cupboards, so finding it difficult to get enough W/m² to heat the room at a sensible UFH temperature. Am assuming that any UFH under the cupboards wouldn't be useful to heat the room.
    •  
      CommentAuthordjh
    • CommentTimeNov 3rd 2021
     
    Posted By: WillInAberdeenAm assuming that any UFH under the cupboards wouldn't be useful to heat the room.

    I assume that any heat I feed into the house anywhere is going to heat it. But maybe that's only justified in a PH.
    • CommentAuthorrevor
    • CommentTimeNov 3rd 2021
     
    Posted By: WillInAberdeenAm assuming that any UFH under the cupboards wouldn't be useful to heat the room.


    But it stops the room heat in the floor conducting out under the cupboards. Think it is not worth leaving it out for the cost of a few metres of pipe. If you think you cannot get enough heat into the room you space the pipes closer together. Most of my pipes are 200 mm apart but in some areas depending on the heat loss calculations they are 150 mm apart. It is akin to fitting a bigger radiator for heat pumps.
  9.  
    DJH, The heat doesn't get out of the UFH pipe and into the house at the intended rate if something is placed on the floor inbetween. Such as: carpet, rugs, or kitchen cupboards. Even in a PH.

    Revor, thanks yes, I'm looking at 100mm spacing to give the greatest possible output, but since half the floor area is covered in cupboards, the effective area of UFH isn't enough.
    • CommentAuthorphiledge
    • CommentTimeNov 3rd 2021
     
    Posted By: WillInAberdeenAm assuming that any UFH under the cupboards wouldn't be useful to heat the room.


    I dont know how much heat escapes but we have the top 30-40mm of the plinth boards cut off so there's a continuous gap all along the top of the plinth under the units. With the plinth boards being set back under the units you dont see the gap unless youre stood right back or crouch down. Never noticed any of the units getting warm so I guess a fair bit of heat finds its way out.
  11.  
    Thanks Phil! Another member of the household works in a profession where they have to be very tight on hygiene and pest control, so gaps in the plinths appear not to be acceptable... even at home!
    • CommentAuthorMike1
    • CommentTimeNov 3rd 2021
     
    What revor says. You'll still get useful heat output from running pipes under the cupboards, even if not at the same rate as the uncovered floor. If you don't put them in, then heat from the rest of the floor will heat the portion under the cupboards anyway through conduction.
    •  
      CommentAuthordjh
    • CommentTimeNov 3rd 2021
     
    Posted By: WillInAberdeenThanks Phil! Another member of the household works in a profession where they have to be very tight on hygiene and pest control, so gaps in the plinths appear not to be acceptable... even at home!

    You can buy vents specifically for the purpose, or easily make your own with some fine mesh and/or metal mesh depending on what you're trying to keep out. We have metal mesh under the fridge to stop any theoretical mice the cats bring in from getting under there. There are blocks of other kinds covering every other hidey hole.

    Others have pointed out that kitchen cabinets on legs don't behave the same as carpet.
  14.  
    If heat could pass easily through kitchen cabinets, then we wouldn't have had condensation in the back of the cabinets, because the back of the cabinets wouldn't have been so cold.

    (Edit: with the thermal resistance of the wall and the dewpoint of the air, we can do a heat loss calc to find out the thermal resistance of the cupboard which resulted in condensation in winter. I make it very roughly R=0.4m.K/W or 4 Tog, which is equivalent to about 10mm of insulation, or a woolly rug.)

    UFH works largely by radiant heat transfer from the floor to the room, which needs line of sight from the floor to the surfaces you want to heat.
  15.  
    I couldn't remember so had to check my build photos. We dint' put pipe under our cabinets or kitchen island. to an extent it surely depends on the heat loss of the house and the temperature you're going to end up running the UFH at.

    We used https://www.wundagroup.com/underfloor-heating/ for our supply (self installed. our sped with very simple manifolds with just two zones for the whole house controlled by the boilers external weather compensation controller (so no internal room thermostats)

    It's been in use for 6 years now and no issues with any of the parts supplied (and they were very competitive on price).

1 to 15 of 15

  1.  
Add your comments

    Username Password
  • Format comments as
 
Back to Discussions Top of Page
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press