I seems to that the notion of "I cant live without a heating system" is very deeply entrenched into our generation.

Central heating has only been with us for a short time and it is not sustainable in it present forms

How do people get educated to understand the ideas of living in a warm environment without one?

my average electrical consumption is higher than I would like -- 43 kWh per day for everything during coldest times 31 yesterday but it was sunny

I am worried that most of this is going into the hrv --- ie my ventilation loss is too big and needs adjusting/fine tuning

I have two small heaters plugged into thermostatic plugs but the never seem to come on -- possibly for a few mins per hour and they are only 750 W anyway

I have no gas no wood or biomass etc

temps under centre of slab has fallen a bit now info on web site

I recon that I need two or three years data for it to get meaningful

Posted By: tonymy average electrical consumption is higher than I would like -- 43 kWh per day for everything during coldest times 31 yesterday but it was sunny
I am worried that most of this is going into the hrv --- ie my ventilation loss is too big and needs adjusting/fine tuning
I have two small heaters plugged into thermostatic plugs but the never seem to come on -- possibly for a few mins per hour and they are only 750 W anyway

If your consumption is 43kWh on cloudy days and only 31kWh on sunny days, your heaters must be coming on - otherwise where is the higher consumption coming from? That they're on thermostats indicates that this is the case - they're coming on to make up for the lack of sun.

How is your hot water heated? I know you have solar panels but is there also an immersion heater too?

What is the fan power rating of your HRV? It should be easy to calculate how many kWh it consumes per day. Even if the fan was 200W and it was on 24/7, that would only be 4.8kWh per day so I'd be surprised if that was the case. If it's 50W then it's only 1.2kWh per day - definitely not the source of your high consumption. Your cold-day consumption suggests that the fan heaters are on for about 5 hours per day.

What temperature are you maintaining in the house? What's the temperature in the basement room? If the floor is at 14.5C that represents a significant heat loss if your room there is at 20C. (See the other thread about effective U values based on surface and air temperatures).

It looks like true passivhaus is pretty hard to attain, even in a UK climate.

Paul in Montreal.

Posted By: tonyThere are thousands of passivhauses in central and northern Europe. -- in much colder climatic areas than the UK and they all seem happy.

And all of them have some form of heating system (ASHP, wood burner, post-heater in the HRV etc.). I don't think there are any examples with no space heating system.

Passivhaus states the total annual primary energy consumption should be less than 120 kWh/m2/year. By that standard, my 112 year old house qualifies. Last year's energy consumption was 110kWh/m2/year (excluding the basement) and 74.5kWh/m2/year if I include the basement. And it's a long long way from passivhaus levels of insulation.

I think it's a laudable aim, but not so easy to attain a design that really does require no heating at all. It will be interesting to see how you do with a few years of ground-warming under your belt.

Paul in Montreal.

In the search for true Zero-Fuel everyone tries for ever-more perfect insulation and airtightness - but IMHO the stoppage is not the heat loss side of the equation, but the solar heat supply side. PH only achieves 1.5 to 2 days heat storage in the above-ground fabric - what happens when there's a week of cloud? How would it be to be able to store for say 10 days in the above-ground fabric, and to increase solar collection (while the sun's out) to fill that, transporting that heat away as it arrives, so avoiding overheat danger. All by simply re-arranging the same or similar building elements.

http://www.tonyshouse.info

If you had said to me that you could be comfortable (almost) without heating 14 months ago, I would have thought you were mad. Having learnt a lot here and improved my house, I can tell that it is (almost) possible, and so can the rest of the family. We need more houses improving to the level of ours and beyond so that people can experience first hand that it can be done without 14 sweaters. If you are living in a cold house with hot radiators, the idea of doing without heating would be scary.
Brian.

''How thick does the insulation need to be to attain the the required amount of hear reduction? ''

Pardon?

Posted By: bot de pailleAs for the best method of attaining zero energy design, wouldnt very large amounts of insulation and airtightnes finaly acheive this if done adequately enough?

What did you think of my comment on exactly that proposition, above?

Posted By: fostertomIn the search for true Zero-Fuel everyone tries for ever-more perfect insulation and airtightness - but IMHO the stoppage is not the heat loss side of the equation, but the solar heat supply side

Ours is not "passive house" being a traditional masonery construction built about 15 years ago.
HOWEVER
it is both easy to heat for its size and due to my insistence on......... 150 inner leaf after a 100mm fibre filled cavity,........ with 210mm solid masonary internal walls,........ with additional insulation below an overthick conc ground floor ..................and concrete floors at first floor level.............all in aid of thermal mass.
it does not drop more than a degree or two over 24 hours without heat.
We run a wood burning stove in the living room with the door open, the heat percolates throughout the rest of the house, backed up by prob an hour each day underfloor and a couple of hours a day rad use, early am downstairs and pm upstairs.
In favour of the passive house concept I would say that it requires noticable more heating during a windy cold week as opposed to during a bitterly cold week sans wind

We built a few Passive Houses last year and like any new building you first need to heat them up to get them going. They do need heat in a cold snap and under the Passive House guidelines they are allowed to use 1.5 litres of Oil/m2, so we can use 300 litres of Oil/annum to heat a 200m2 house = 15Kw/m2.a. If it goes above this then we either have a Cold client who likes 23 degrees or we have not done the calcs correctly.

Hi Tony

How much pipe did you bury under your basement?
What temperature did the soil reach last year?
How long has your underground loop been connected to your Solar Collectors?
How many m2 of Solar Collectors do you have?
Why is your basement colder than the main house if there is heat in the ground?
You have no insulation under the floor over your heat store I gather?
If this is the case how do you stop the basement overheating in the summer when the ground is fully charged?


I am in the process of re-doing my roof and I plan to run 1000m of water pipes between the felt and the slates to collect heat that will be stored in the soil under the house and in an insulated ground box in the garden. I will insulate over the ground store with 300mm EPS and use a Fiwihex radiator to take the heat back out in the Winter.

Hi Tom

One of my quandries is which pipe to use, plastic or copper? I'm worried about sagging and aging of the plastic pipe, should I be worried about the copper corroding? The copper is more expensive!

One of my quandries is which pipe to use, plastic or copper?

I'd be worried about the affect of temperature cycling on plastic pipe. The temperature range is a lot more extreme than in underfloor heating or ground source heat pump collectors.

Copper will not corrode, it has a long track record as a water pipe! However, it will cost more to buy, will be more difficult to fit tight against the absorbing surface, will probably need expansion joints & will cost more to install.

How do you plan to handle frost protection?

David

VH --- Pipes in two boreholes 6.5m below basement -- 6.5 loop in one and a 6.5 with a 3.5 in the other all plasticy ; soil got to 16.5C --- solar only dumping for sept and oct; I have 90 ETs -- about 10m^2? -- the soil under the basement hasnt warmed up yet and the rest of the house is so well insulated and warm that in comparison the basement feels cool air 20.5C floor and ankles 18 C, I have 25mm eps as this was cheapest way to do floor, (I have wing insulation too; When the ground is fully charged I doubt that I will be able to get it so the basement would be uncomfortably warm though I dream about having to sell a solar panel cos its all working too well -- easy to stop heat going down there. Soil 1m down under the middle is 14 C today

hope your heat store works.

Hi Paul

I was talking about what pipe to use under the slates and whether plastic pipe would go soft like a garden hose if it got too hot and how that would effect it long term. I think its not designed for temperatures above 80 degrees. I was planning to use antifreeze. I was planning to have 3 seperate collection zones, east roof, south roof and west roof.

Hi Tony

Did you meet water at all in your boreholes and have you checked any geological information regarding underground acquifers and their movement and the way the heat you generate could move under your neighbours house after a year. I visited some Greenhouses in Holland over the Christmas holidays that were using Fiwihex technology to capture and store summer heat from the greenhouses in underground acquifers. If the Acquifer moved 10m per year (like an underground swimming pool) then they pumped the water directly into the acquifer in the summer and back out 10m away in the winter, like 2 wells.