Wednesday, March 30, 2011

Movie about how a MHRV systems works


Sunday, March 27, 2011

This will only work in a Passive House: Heating with nothing other than fresh air

compact unit ventilation+heating+dhw for passive houses
This is the know "classical" compact unit: all building services are realised in one handy appliance:
  • heating,
  • ventilation and
  • domestic hot water.
Everything is centred on the element of air: air is the medium that transports the heat (on the supply side), air is the heat source of the heat pump (on the exhaust side). Of course, if necessary, the air could be cooled and dehumidified as well, using the same equiment - that might be interesting in hot climates.
Note that only the fresh air required for indoor air quality is used, there is no recirculated air. That is a difference to the systems in wide use e.g. in the US; those use only recirculated air and a far higher air flow rate.

Fireplace, which is the main heating system in a passive house in Friedberg (architect: Blumrich); this automatic oven is also heating domestic hot water; during summer thermal solar collectors top the concept off.

Compact Units available on the market.
Idea #1: Use the fresh air required for indoor air quality also for heating the building
A building occupied by human beings needs fresh air. If the fresh air supply is left to good luck, it should not surprise if indoor air quality (IAQ) worsens.
If on the other hand the heat from the exhaust air is not recovered, there will be significant ventilation heat losses. It is impossible to realise an energy efficient building in this way - especially if the indoor air quality is to be high as well.
Therefore, for energy efficient new construction or refurbishment a mechanical ventilation with heat recovery is really necessary - this at least holds for cold climates (climates, in which one needs a heating system) and in hot climates (climates, in which one needs active summer cooling). For a detailed discussion of this point, have a look at our page on the topic ventilation.
The supply air, which is delivered by the air-to-air heat exchanger, can transport some heat, too. It is not a huge amount, but just 10 W/m² can be delivered to the supply air rooms using the fresh air required for good IAQ (see the calculation on heating capacity of fresh air). That will not be sufficient at all in conventional houses. But in a passive house, the peak heat load requirement is extraordinary low. Indeed, it will be so low that these 10 W/m² available from a fresh air supply will be sufficient (that in fact is the defining condition for a passive house). Thus, some simplified building services systems become possible in passive houses: “Heating with the ventilation system”, without the need for additional ducts or even without the need for a higher duct cross-section dimension. If, in addition, the heater for the supply air is integrated within the ventilation system and the domestic hot water boiler, one ends up with an integrated compact unit:
Heating, ventilation, domestic hot water and cooling (if necessary) can be supplied by just one appliance. Many solutions can be chosen for heat generation:
  • Use of a small heat pump (Compact unit with heat pump, see figure at left hand side)
  • Use of a small condensing burner (natural gas compact unit)
  • Use of a small combustion unit for biomass fuel (e.g. straw-pellets).

Passive House: Comfort through Efficiency

The Passive House is the world’s leading standard in energy efficient construction: Energy saved on heating is 80% compared to conventional standards of new buildings. The energy requirement for heating is lower than 10 to 20 kWh/(m²a) (depending on climate), adding up to a low cost of 10 to 25 € per month. Therefore high energy prices are no longer a threat to Passive House occupants. 

Exceptionally efficient components and a state of the art ventilation system, achieve these huge savings without compromising comfort, but rather increasing it.

The Passive House concept is a comprehensive approach to cost-efficient, high quality, healthy and sustainable construction. The concept is easy to understand:

  1. Contemporary construction is quite airtight, therefore the air replacement from infiltration is not sufficient. Ventilating by opening windows is not a convincing strategy either. Getting a sufficient volume of fresh air is not just a question of comfort, but a requirement for healthy living conditions. Therefore mechanical ventilation is the key technology for all new construction as well as refurbishment of existing buildings. Mechanical ventilation will work in all cold and all hot climates since in an airtight house, the heating and cooling energy required will be significantly less.
  2. Even though mechanical ventilation systems raise initial investment costs, if designed efficiently they will reduce energy costs significantly, eventually paying off the initial cost.Ventilation units suitable for Passive Houses allow for an economic operation.
  3. Now we explain the central "trick" of the Passive House concept: The fresh air needed is entering the room anyhow. If one could use this air to cover the heating load, without increasing the mass flow, without recirculated air, without noise and without drafts - then the ventilation will pay off a second time.
  4. This concept of "fresh air heating" is only possible in a building with superior thermal insulation, just like a Passive House. For experts: This is the defining requirement; the maximum heat load should be lower than 10 W/m² , allowing the fresh air to carry the heat load.
Passive Houses require superior design and components with respect to:
To realise an optimal interaction of all components, an energy balance of the building has to be worked out. And step by step any new design may be improved to meat Passive House standards.
Thousands of Passive House dwellings are already occupied. Examples will be shown in workshops at the Passive House Conference:
  • Design, redesign, create scopes of opportunity: architecture and the Passive House
  • Passive commercial buildings
A tour of the built  House will follow.

Wednesday, March 23, 2011

Walls have arrived

Our super insulated prefab walls from Ray-Core have Arrived at the job site. We are Ready for Building our super insulated Walls .

One 53' Trailer full of our Panels.

Offset 2x6" Studs to eliminate Thermo Bridging in the Walls R 52 Foam core insulation Ray-Core .

Sunday, March 20, 2011

Selecting Tiles

We are going with larger tiles ( 1.2 m x 0.6m  or 4'x2' ) for most areas on Bathrooms walls and Floors.
Master bath Floor black slate with cream Limestone on the walls and Wood Cabinets. Contact me for supplier info if you like some for your house.

Nice Texture