Q & A
Question: How is draft or air flow controlled within a comfort ventilated area ?
Question: How does the ventilation system deal with potential odour problems that are likely to occur in the kitchen, bathroom or toilets ? How long does it take i.e. for cooking vapours to disappear ?
Question: How noisy is the ventilation system ? Can very sensitive people hear it ?
Question: Can we open in a passive house window ? Are there actually windows that can be opened in a comfort ventilated room ?
Question: How exactly and precise can temperature in the various rooms be altered to adapt to our different needs ?
Question: How do we avoid allergies, are there filters in the ventilation system ?
Question: How will we achieve optimal humidity, which should sometimes be individually different ? Are humidifiers and dehumidifiers integrated and how is that controlled ?
Question: Many people are afraid of an overly complex technology. Should systems and controls - where possible - not work automatically and unnoticed by us ?
Question: Can we also cool down our house with such a system in summer ?
Question: How then does such a system look ? Do I have to look at a lot of pipes and ventilation grilles ?
Question: What happens in a passive house if (i.e.) the electricity goes out ?
Question: Do passive houses always have to have boxlike forms ?
Question: Is the ground floor cold?
Question: Is there an opportunity to visit a passive house ?
Question: What does PHPP mean ? Why do I need it ? Is it absolutely necessary to have it ?
Question: Is it true that a passive house has no heating?
Question: Is it possible to have an open fire place or an oven in a passive house ?
Question: If I want the house to have a higher inside temperature i.e. 25 degrees, is this possible ?
Question: Very often passive houses are built without a basement.Why is this so? Is it not possible to build a passive house with a basement ?
Question: Is it possible to build a passive house in an area that can be quite foggy at times or has little or no sun in the winter months ?
The speed of the air flow is so low that significant air movements cannot be felt. The air flows in a passive house are anyway lower, given that if compared to conventionally constructed buildings, there is no convection due to high surface temperature differences (warm radiators / cold glass surfaces).
Wet areas (bathrooms) and toilets have an increased automatic comfort ventilation. Even with an open plan cooking unit odours do not spread around the apartment or house and after short time are no longer noticeable. In the kitchen a re-circulated extractor cooker hood cuts out about 90 % of the residual fat in any kitchens vapour.
Based on our experience with hundreds of passive structures we are now able to fine tune the systems so that the residents cannot tell the difference between ON and OFF. An automatic comfort ventilation must bring an increase in comfort in all sectors of comfort – also when it comes to sound and noises. By the way: The ventilation also cancels out noise transmission between two rooms in static air, a common problem otherwise between two non ventilated rooms.
Of course there are windows that open in every room. And they are allowed to be opened whenever you want (in winter it has the same consequences as in conventional buildings: it will be getting cold). However: Based on the experience of many of our customers after some time of living in a passive structure one rarely feels the need to open a window, because the air quality is extremely high and unwanted drafts of cold or hot air would otherwise be entering.
Basically, there is a relatively even temperature in a passive house, since the buildings intelligent skin is insulating it very well. Sometimes however, the bathroom should be warmer or the adult bedroom cooler than the rest of the house. For the bathroom there are many solutions (FBH, e-heater, heated towel racks, etc.). In the bedroom you can open the window if needed (tilt windows short-term, or even overnight). It's that simple. But we have also already learned that one can sleep pretty well at 20 ° C as long as the air is fresh (remember the old misbelieve: 'only cold air is fresh air'), so usually people stop opening windows after a few weeks. But it is best to convince yourself: Try living in a passive house, or talk to a passive house resident, we are happy to provide you with a contact.
Due to the automatic comfort ventilation, allergenic particles can not even get into the house. The incoming fresh air from dust to pollen is cleaned through fine particle filters. Thus, an automatic comfort ventilation, especially for allergy sufferers is a real blessing. Hygienic concerns can be dispelled: The incoming air pipes remain permanently clean because of the filters. Over time, the exhaust pipes may get a little dust coating but that air flow is the one that exits the house or apartment, it never will come into the room.
Counter-question: What happens in the conventional house? First, the room is heated (like in the passive structure). Second, the building is ventilated through windows (even in winter) to ensure adequate air quality (in the passive house the comfort ventilation does this). Third, due to the supply of dry outside air the relative humidity in the room will be reduced (also happens in the passive house). Now: If that is too dry or the other way round - which is felt individually different, depending on the person- you may have some laundry to dry, may have some plants inside, may use a humidifier or the reverse of it. That is exactly what you can do just as well in a passive structure.
If you can master a normal heat control station of your heating system or of your air-condition, you will have no problems with a comfort ventilation system. It works mostly automatic and gives you just a few options to” play around with”. Nothing difficult at all.
Every three months of operation, the user is prompted to change the coarse or heavy dust filter. The fine particulate filter in front of the heat exchanger is usually exchanged once a year. Both filters are as easy to change as are the filters of your vacuum cleaner. Other than this we do recommend that every three years the whole system is checked briefly by a specialist. And that's it.
The first device the incoming fresh air will pass through is a fine particulate filter. It allows no dust, but also no other particles (down to the size of pollen) into the system. Furthermore, the incoming air has a tendency to get warmer and dryer as it travels through all sections of the pipe system. Therefore, for the emergence of mould or fungus both the germinal material and the moisture are missing. And the continuous investigation of a large number of such building ventilation systems does actually confirm: The air entering into the room due to filtering is in all cases cleaner than the outside air. And should there really be something in the system, all sections are cleanable with a simple brush.
In principle is possible to bring in cooler air in summer. However, because the system is working with such small amounts of air you can not compare the system with an air condition unit. In summer it is possible to bring in air with 16-19 ° C, but since you do that with only 200 to 400 W, the cooling rate is very modest. Passive houses are already designed in a way that an active cooling system is not necessary: Good thermal insulation (works very well from both ways) and outside shading of the glass areas will always ensure a comfortable temperature.
Pipes are usually not visible, as they are in the walls, ceilings, etc. Air inlets and outlets are available in a lot of different forms, so that something can be found for every user. And even they can be designed to literally be almost invisible.
All conventional heating systems are dependent on one or more energy sources: a gas heating requires gas and electricity, an oil heating requires oil and electricity. A wood fired heating requires wood and electricity. The compact ventilation and heat exchanger (heat pump) unit needs only electricity and only very little of that. Here you may also ventilate the possibility to cover this need by a photovoltaic system. And when the power fails for many days: Even in deep winter the temperature in a passive house does not fall under 16 ° C. Not bad, right ?
Basically, all styles, forms of buildings or taste preferences can be realized. But since the passive structure must always function in its desired standard independent of shape and form, the involvement of an experienced planner is recommended. He will bring the basic passive house requirements, such as compactness of the building form, proportions of windows and much more in line with the architectural specifications.
Due to the high quality of insulation, which is also implemented in the floor structure (whether with or without a basement), the surface of the floor always reaches approximately room temperature. This is especially important during the seasonal transition periods. In a simple low-energy consuming (not passive) house the floor surface is usually too cold during the seasonal transition periods, which makes them uncomfortable.
As a passive structure pioneer, our company Weissenseer can utilize and rely on its vast experience as we have realized hundreds of passive houses. Take a look at our buildings, talk to its residents - see for yourself, we are happy to arrange contacts.
PHPP = Passive configuration package. PHPP is a program of the Passive House Institute in Darmstadt (Germany), with which the passive house standard can be verified. Using the PHPP the requirements and configurations for a passive house at any location in the world can accurately be verified and calculated. The PHPP will show the exact needs of thermal intake and dimensions possible. Those data exist for sunlight, sun direction, wind, moisture and temperatures at any possible place. Without the prior result of a PHPP calculation we would never implement or start the fine planning of a passive structure.
It is true that a passive house does not need a conventional heating system such as oil or gas heating. Theoretically, of course, all types of heating in a passive house are thinkable, but they generally produce much more heat than needed. The little heat that is actually needed, can be supplied through the ventilation system. This saves the cost of a heating system, the installations, the heater and the heat distribution and it does save space as well.
Of course. If a client desires "a visible fire", this can be taken into account also in a passive structure. One only has to make sure that the furnace is passive house feasible (i.e. inflowing air can arrive independent such as through a canal to the outside and cold air cannot enter the building when the fireplace is not in operation ...). As the intelligent skin of the passive house is very well insulated and the desired temperature already exists, the operation of an oven or fire place will heat up that space relatively quick, so one will have to think also about a separate ventilation to cool it down. But easy to do.
The heating of a passive structure is the easy task. Since while constructing and dimensioning the service installations one always carefully aims not to oversize them one would only have to slightly adopt those dimensions to have them work at much higher temperatures (such as we do i.e. in Kindergartens…) The important thing though is that this is already taken into account during the planning phase of the structure.
A passive house with a basement is no contradiction. But it is to decide whether such a basement is inside the thermal hull or remains unheated. If the basement shall be in the thermal hull, it is important to take this into consideration when planning the house. If the basement is outside the hull (as it usually will be…), it is important that there is no thermal bridge between the basement and the ground level.
In such a situation it is especially important to create a passive structure. One can reach the passive standards such as the heating demand of 15 kWh / m² a or the heating load of max. 10 W / m² everywhere, but may have to use a different system dimension. This is already known using PHPP (see above). The potential savings of the passive structure if compared to a conventional building on a "difficult" site are logically even higher than in a sunny location.