Questions about Heating

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Does a Passive House need a heating system?


A Passive House needs what is referred to as a ‘back-up’ heating system, which is considerably smaller in comparison to that required for a conventional house. A Passive House may need 3kW of heat at the coldest time of the year whilst a conventional oil boiler produces 20kW.

What kind of heating system is typically used in Passive House?


Typically any additional heating required is delivered using the backup heating system through the mechanical ventilation system installed in a Passive House. The fresh air passing through the house can be heated via different means or methods (such as a pellet burner or electrical heat pump).

What is the difference between a ‘back up heating system’ and mechanical heat recovery ventilation system?


The mechanical ventilation system provides a constant flow of air throughout the house via means of fresh air supply which is heated via the extracted stale air’s heat through means of plates and conduction. When this stale air is perhaps not hot enough to provide the necessary heat required within the system, the backup system comes into play and provides the required amount of heat to supply the constant temperature desired.

Does my Passive House need radiators or underfloor heating?


It is unusual to find these within a Passive House as often they are simply not needed. Of course, if you really want to install these systems, this is possible but you must keep in mind that you are adding costs which in turn unnecessarily increase the cost of construction.

Can I control the temperature in my Passive House?


Of course you can. A Passive House is designed to deliver a constant 20°C throughout the dwelling although different people have different comfort levels so this system can be designed in such a way that the temperature can be changed via means of conventional room thermostats.

Is it true that a Passive House can’t have an open fireplace?


Yes unfortunately this is true. This is due to the air tightness which is completely necessary in order to achieve the Passive House Standard. An aesthetically pleasing compromise is the installation of a wood burning stove as this has a sealing door or a bio-ethanol fire to produce that real flame effect in the home.

If the house is unoccupied will the house cool down?


Yes but very slightly and definitely nothing like a conventional house. The heat loss in this case, due to the quality of the insulation, will be minimal. The temperature changes only very slowly – with ventilation and heating systems switched off. A passive house typically loses less than 0.5 °C (1 °F) per day (in winter).