underfloor heating, suitable to heat a room or will i need radiators aswell!!

stolt

Hi everyone, looking for some advice, we are in the process of having a glassbox extension on our house, the whole room size including the extension is about 20ft square. It will house our kitchen and small dinning table plus a seating area, wife classes it as a family room!! just discussing with a electrican tonight about him doing his work and feeding the new kitchen with wiring for the cooker and induction hob etc. We mentioned the underfloor heating and he said he wouldnt be so sure it would keep the room warm enough and said perhaps a wet underfloor heating system would be a better option and keep the room warmer. I'm concerned myself that if it was a cold winter morning the room would be freezing first thing in the morning so heating would have to be on all night (costs!!) so perhaps a radiator will need to go in there aswell. The extension (builders) arent doing the kitchen as we havent the money for it yet but they will do the underfloor heating in the extension and the kitchen.

the extension has a 20ft glass wall and a smaller 10ft glass wall but has a solid roof and one wall so its not as bad as a conservatory.


Its driving us mad and i have seen sarah beeny on tv moaning at people saying they need to list everything down and this build has just run away and different jobs are needing to be done before others and well i think its done my head in!!!

The initial question was just about the underfloor heating (Electric), but on a wider scale if you have been through this type of thing yourself any tips...

stolt

Heres a pic of a rough floorplan..

missile

Looks very smart. Impossible to say, without detailed knowledge of the method and materials used for construction as these will affect the insulation values. Your architect will be the best person to advise you. He ought to be able to calculate the heat loss and heat imput required.

Wet underfloor heating is generally more expensive to install but cheaper to run.

stolt

Hi, yes we have had a surveyor that was part fo the company that are installing the glass extension. he has been aroudn the whole house and measure windows and walls and there insulation properites, apparently this extension will be more energy efficient that the house. i just dont know now whether underfloor heating will be enough for the whole room to make it a comfortable heat or just keep the floor warm or indeed how much the cost will be to constantly keep it on. Whether to keep a radiator in the room aswell? too many questions that i dont know the answers to. Have tried contacting the surveyor today, on this and also the waste pipes laid into the floor now look as if they are 300m in the wrong direction which means they will not be under our kitchen units!!!

arrgh pulling the last of hair out of my head !

left messages with the office to ring me back but they are overworked because the gaurdian run a review on them in a sunday magazine and they told us it has gone really busy since then, so i susppose we are suffering ebcause of that magazine run.

Anyone think itwas worth discussing with the building inspector that comes round, he would have had to approve it all beforehand, ie heat loss etc.

andrew-b

Sounds to me like you need to get an opinion from someone who knows what they are talking about..i.e. a qualified/experienced heating engineer with experience of underfloor heating systems and not a more general electrician, builder or site foreman etc. The only real way to get an answer is to do a thermal loss calculation for the room and then see if you can find an underfloor heating system that will give sufficient output. With the amount of glass (incl. skylight) the heat requirements for the room will be much greater than if it were solid wall with a few windows in.

Heat from radiators with a relatively small surface area can be fairly localised - feeling hotter near the radiator than the other side of the room whereas with underfloor heating your covering the entire room and it will be less likely to have localised hot spots.

If you've got a tape measure, pencil, paper, bit of time and a calculator you can do a fairly decent heat loss calculation yourself. Have a look here. Once you've got a figure for the room you then have a starting point to assess whether underfloor heating systems will be upto the job and whether they meet your budget. If it were me and could afford it i'd probably have a wet underfloor heating off the main gas central heating system rather than an electric one as gas is cheaper per unit kWH.

HTH

Andy

stolt

andrew-b wrote: »

Sounds to me like you need to get an opinion from someone who knows what they are talking about..i.e. a qualified/experienced heating engineer with experience of underfloor heating systems and not a more general electrician, builder or site foreman etc. The only real way to get an answer is to do a thermal loss calculation for the room and then see if you can find an underfloor heating system that will give sufficient output. With the amount of glass (incl. skylight) the heat requirements for the room will be much greater than if it were solid wall with a few windows in.

Heat from radiators with a relatively small surface area can be fairly localised - feeling hotter near the radiator than the other side of the room whereas with underfloor heating your covering the entire room and it will be less likely to have localised hot spots.

If you've got a tape measure, pencil, paper, bit of time and a calculator you can do a fairly decent heat loss calculation yourself. Have a look here. Once you've got a figure for the room you then have a starting point to assess whether underfloor heating systems will be upto the job and whether they meet your budget. If it were me and could afford it i'd probably have a wet underfloor heating off the main gas central heating system rather than an electric one as gas is cheaper per unit kWH.

HTH



Andy

thanks, yes we do, kinda being lead by someone that has fitted these glass extensions before but I spoke the boss today and i raised my fears about it not being warm enough and he said that careful calculations have been done on the heat loss of the house and the extension itself and he said it will be fine. I mentioned that the missus always feels the cold so and what was his feelings about the fitting rads aswell, he said in its our call but in his opinion we wouldnt need them. The building inspector reckons he would fit rads aswell to be on the safe side. So i think aswell as the the underfloor heating we will install two radiators aswell.


Phoned the kitchen people and they are coming out on monday to look at the wastepipes to see if there ok, form the soudn of it they said that these types of problems can be overcome so not to worry......

misskool

with regards to the waste pipes, if the builders had detailed plans surely you can ask them to rectify them and get them to fit according to the plan?

stolt

misskool wrote: »

with regards to the waste pipes, if the builders had detailed plans surely you can ask them to rectify them and get them to fit according to the plan?

Detailed plans is a grey area!! the kitchen people were reluctant to release the plans to us until we have paid for the kitchen or at least part of it (the kitchen isnt even planned until mid next year due to funds). So they had some drawings with some measurements on there but as the builders and the kitchen people are different companies the extension hadnt started when the kitchen people came so there is a nib a tth eend of the house where the wall has been taken out which is appx 300m square, the kitchen people have taken the teh measurements from outside of the nib and the builders have worked inside the nib. I suppose we have to take some kind of responsibility but thats perhaps us being too naive and believe they all know what there doing, i've watched neough of the tv programmes where it all goes wrong so i dont know why i thought we would be any different.

i've tried to draw a plan of what i mean, as its awkward to explain.

stolt

heres another plan, in plan you can see where we were going to have a unit to cover the nib of the wall which the worktop would start further forward intot he glassbox

andrew-b

If the waste outlets are in the wrong place (300mm not 300m i assume!!) then i'd get them to extend them to the right place. Yes it might involve digging up a small piece of floor but at the end of the day it's you who have to live with it not the builders or kitchen company. A foot can make a difference between making it usable space or dead space of no use. Obviously your spending alot on this so you want to get your moneys worth out of the space.

The waste pipe is easy enough to extend at the moment IMO - it's not ideal having extra joins under the floor but it should be ok so long as it's solvent-weld pipe and plenty of solvent is used (we had to put a join in the waste pipe for our shower under the concrete floor as there was no other way - was well tested before filling in the hole!).

However i'm not convinced your kitchen design is a very good one TBH - it doesn't work for me with the positioning of the door to the room and the narrow passage into the larger dining/lounging part of the room. Your walking into like the cramped part of the room with limited access to the family dining and lounging part of the room which i suspect you'll use more hours of the day and won't give a good impression of the space the extension is creating. With children around you don't want them under your feet when you're cooking etc. On it's own (if there weren't the extension or the dining part) the kitchen design is ok..but it's how it fits into the rest of the space i have reservations about. If it was me i'd either swap the dining and kitchen parts over (if it's not too late!) so your walking into the dining area or i would change the position of the door (no idea how this fits in with the rest of the house though!). I also don't like the idea of using the sink worktop as a bar. Anyway apologies if it sounds like i'm tearing your plan to shreds..just i feel you could make the room work better as a whole with the seating and dining areas.

Andy

stolt

hi I know exactly where you coming from, the plan is not dead cert, but in the initial stages my wife had three functiosn she wanted from the room, kitchen, light dinning and lounging. We have three girls under 7 and the youngest is quite ill at the moment and needs a fair bit of attention so we wanted a room we could all spend time together, the trouble is my wife ahs very set ideas on what she wanted the kitchen to look like, ie the big bank of floor to wall units.
Its something I've mentioned a few times regarding the layout and i agree we have this big space and the kitchen is suppose to be the heart of the home and with us it is effectively cramped into what was the dinning room and near enough the smallest room of the house. I want us to see some more kitchen shops and designers but despite the size its awkaward to everything that she wants int he space we have, probably going to get many people come back and say but thats amassive space how can you not get everything in!! its probably the initial build and the problems that have took it out of us.