flooringissues
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Well unfortunately I can call myself something of an expert on black mould, though not in connection with underfloor heating.
"Astonish" mould remover, in a green bottle, wipe off after 5 mins. Once a year, about late January, does it for me
Its really not a big deal.
That is interesting JohnJay, as builder told us since its a new houes, a3 rating, it's super warm and that will cause black mold to form quicker than seen in older houses.
I have found a lot of material online about it... but i don't know who to trust.
I go on to one website and it states you can't use hardwood, the next says you can.
One independent (seemingly) said that wood could be used but had to be very cautious to prevent moisture damage. i.e. let the subfloor and wood acclimatise over a few weeks.
Not sure if its any use but i seen a test before where someone stuck down a large square of see through plastic to the ground for a few days and seen if water formed underneath it. This was to test if the room would be suitable for wooden floors.
However, I totally disagree with a couple of statements made up thread to the effect that "wood is an insulator so your system will be more expensive to run" and "you'll have to set the temperature higher to compensate". Where does one imagine the supposed additional energy goes (assuming one believes in the conservation of energy, the most basic of physical principles)?
Yes, I took a look. All it tells me is that you will get a higher temperature gradient through a more insulating material. That's what I'd expect. Their example uses a fixed energy flux of 70 W/m². That's the definition of your energy usage. The fact that you need a higher temperature gradient to achieve it has no bearing on the energy usage. All it means is that the water flowing through the pipes will lose less energy for a given temperature than a less insulating material -- that's the definition of insulation and is why you need the higher gradient. 70 W/m² is the same energy output regardless.Did you go through the Junckers calculations? It's certainly not in their interest to make those claims. The temperature mentioned relates to the temperature of the water in the heating system, not the stat temperatures.
This is the bit I don't understand. How do you figure that? Those Junckers calculations aim for a given temperature at the floor surface. Assuming adequate underfloor insulation (without which UFH wouldn't work at all) the heat losses in your room (through walls, windows etc., being measured in W/m²/K) only depend on that surface temperature. Differing floor materials in different zones make no difference. The thermostatic controls simply ensure that a zone with a more conductive floor material cuts out quicker, giving the same floor surface temperature and same energy flux. As I've said, I've been using UFH for more than a decade, with a mixture of wood and tiled floors, and the temperature stability in all zones is to within a very impressive couple of tenths of a degree.But you'll also get a higher portion of losses trough the system unless insullation levels are increased, so it will cost more to run, and it will be less responsive, but the latter generally isn't an issue if the house as a whole has a high standard of insulation. There'll be further complications if there are differing flooring materials, especially within a single zone.
Note that additional energy to get the floor to temperature is not "wasted" as this will all come out through the floor surface (including during the matching longer cool-down times), minus any additional sub-floor losses. The rest is undoubtedly true, but it is worth calculating a realistic magnitude of the losses. The Junckers examples linked earlier gave a temperature difference (ΔT) of 4 degrees to overcome the thermal resistance of 14mm boards (similar to what I have) at a normal 50 W/m² output. That rises to 9 degrees with 22mm boards at 70 W/m². As you say, real world effectiveness of underfloor insulation depends on factors like thermal bridging but these can be taken into account (assuming a quality installation) by considering the ratio of floor area to perimeter length. Here are tables for various ratios and thicknesses of Kingspan TF70 insulation: http://www.kingspaninsulation.ie/getattachment/5fdd04b2-e58e-4622-97bb-5861799ab02a/Therma-TF70.aspx and for "Kore Floor": [broken link removed]No insulation is 100% effective, with thermally efficient floor coverings, you will only have small losses via through the sub-floor insulation as the heat generated passes easily through the floor into the room. The higher the insulation value of the floor covering, the higher the percentage of heat energy will be lost through the sub-floor insulation into the ground.
To deliver a set amount of heat energy into the room, the slab will have to be heated to a higher temperature. Initially, this will result in a higher energy use to get it up to temperature, how much more energy this will consume over time will depend on the rate at which this built-up heat energy is being lost at and how often and for how long the heating is running.
If you have very deep/ effective insulation under the floor and very careful attention was given to eliminating thermal bridges during the construction, then losses will be minimised, but you will still have losses.
Apart from subfloor losses (which are negligible) that has to happen. Where would the energy go otherwise?The additional energy used to get the slab up to temperature is wasted unless the cool-down time is so long as to maintain the temperature above what it naturally falls back to before the heating is switched on again.
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