Underfloor heating and insulation questions

[chimpster]

That seems quite economical, the reasons we ruled out wood pellet so far were briefly: lack of guaranteed supply source, variable pellet quality, stories of rodents nesting in pellet storage area, plus space and storage conditions required. Would consider pellets if I got a some feedback on the above (realise that these have been covered in some previous threads, but it seems to be a developing market)

Its quite economical alright. There are a few reasons for this. UFH runs from a set of stats in each room. I have 3 rooms with big south facing windows. These 3 rooms would be in excess of 600 sq foot. Basically the UFH only comes on in these rooms in the evening after the suns goes down in the evening so I expect my usage to go up in the winter time. Also as I said my DHW isn't connected yet so this will need another 2/3 KWs once its connected though the Solar should take care of alot of this heating need from April to October.

As for storage. Well I have a friend who has a Kedco franchise so I got well advised on all the options. I basically have gone bagged for now but I am awaiting an outdoor silo which will store my 3.5 tonne. I will run my augur through the wall of the garage and in to this outdoor silo so I will have automated pellet feeding. Kedco are also supplying me with the pellets. The quality has been good so far anyway. As for rodents, I haven't heard anything about this before, any pellet storage area should be sealed tight anyway so they really shouldn't be able to get in there.

 

[eroe]

Hi
We have UFH on two floors of a 3 storey split level house. Rads in attic level, which are bedrooms. We used 250mm Thermo kind insulation (high ceilings and lots of glass) The quality of heat is fantastic. Reused existing kerosene boiler, planning to change to geo thermal when finances permit.
The rads are over sized (to allow for future change to geo-thermal) but saying that they are rarely turned on as the high level of insulation keeps all the heat in. One mistake we made was not putting in a heat exchange unit - they are very effective especially with UFH. Good Luck and get on to the UFH people asap.

 

[mickeyg]

Three have been discussions on various threads on the suitability of various types of timber floors for UFH. I am particularly interested in the suitability of solid wood flooring for UFH. Can anyone give me a definiive position on this.

m

 

[keeper]

Hi
We have UFH on two floors of a 3 storey split level house. Rads in attic level, which are bedrooms. We used 250mm Thermo kind insulation (high ceilings and lots of glass) The quality of heat is fantastic. Reused existing kerosene boiler, planning to change to geo thermal when finances permit.

eroe, can you give me a ball park on running the UFH with kerosene, and also guide on house size, my research so far says oil is very expensive for UFH, also Mrs Keeper likes her heat, so how many hours a day is it run?

 

[eroe]

Hi Keeper, are you sitting down? €1500 a year!! it is on about 6 hours per day in the middle of winter. (I like mrs keeper like a warm house!)
We have had it running 2 1/2 years like that (on a boiler which is 15+ years old) - and hope to get it down to 20% of that with geothermal when we install it. House is just over 2000sq ft. Hope that helps!

 

[lfcjfc]

Hi Eroe

As MickeyG says there are a lot of discussion threads on this - reading through them the cost in terms of electricity to run a Geothermal system was the subject of much debate. Reducing your costs to 20% of €1500 per year, ie €300 per year would be optimistic based on some experiences. To be honest it was the huge range of numbers quoted on geothermal running costs vs the capital expense that eventually turned me against it

 

[eroe]

Hi lfcjfc,
You may well be right but hopefully we can reduce from €1500! The environmental concern is also important for me.

 

[keeper]

Hi lfcjfc,
You may well be right but hopefully we can reduce from €1500! The environmental concern is also important for me.

Actually, €1500 for UFH on oil per annum does not seem too bad, what type of construction/insulation have you got. We have got several quotes for Ground Source/Borehole heat pumps, but these seem to start at about 15K+ and the skys the limit after that, and no-one is prepared to commit on actual running costs, which makes me more that a little wary. They all say use night rate electricity, but I don't really need the heat when we are asleep. Primary heating requirement will be mornings, evenings and weekends during the winter months, so I don't really see the savings for night rate electricity. Also the capital costs for heat pumps or a properly specced wood pellet boiler would buy a lot of oil.

 

[Maurice Kell]

When putting underfloor heating on a concrete slab unstairs should you lay directly onto the slab of put foil backed insulation down berofre laying the pipe work.

 

[inchbyinch]

Maurice

Welcome to AAM

I personally would lay insulation ,clip UFH onto that and float in screed. As if you were to leave it out the heat would radiate in all directions instead of just up you need to encourage the heat up as much as anything else other wise you will be using your first floor heating to heat your ground floor aswell.

As to how much, I would consult an expert. perhaps you could ask some of the people here who have installed it as real experts seem hard to find on this topic (i.e. people who have been at it years and know exactly what they are on about)

I would pay particular attention to your control system and temp stats, they are what will really make it efficent, its not really as simple as a boiler and rads which you can turn on and off, it needs to get information all the time.

Rgds
Inchy