Ventilation

Ventilation - change of air by natural (passive) or mechanical (active) means to and from space or spaces in a building. Also, it could mean a control of thermal comfort in a building as well.



According to the Approved documents Part F, 'ventilation is required for one or more of the following purposes:
a. provision of outside air for breathing
b. dilution or removal of airborne pollutants, including odours
c. control of excess  humidity (arising from the water vapour in the indoor  air)
d. provision  of air for the fuel-burning appliances.'



Types of ventilation:

Natural ventilation - it depends on pressure between the inside and outside the building. Difference of the pressure appears because of the temperature changes, wind strength, people activity etc. Natural ventilation does not require any ductwork, fans, conditioners. The fresh air flow gets in and out through the windows, louvres, grills, air leakage paths (thermal bridges). Natural ventilation has both good and bad sides. It is energy efficiency system which lets the fresh air enter the building, however, it is not always controllable and may cause heat loss.

Mechanical ventilation - is a system which use electricity to move the fans, drawn the fresh air through the ducts inside the building and collect the existing air out of the room and exhaust it outside. Mechanical ventilation, also, has its own advantages and disadvantages. Even though it does not cause so much heat loss as natural ventilation, it consumes energy to operate the system.

Mechanical extract ventilation 

There are 2 types of mechanical ventilation:

Mechanical extract ventilation (MEV) - this system should be installed in all 'wet' rooms. It continuously extracts moist air from bathrooms and kitchens and takes it through the ducts into the outside. Then the air into the 'wet' rooms are replaced by the fresh one which comes through the background ventilators (doors, windows etc), through thermal bridging and building fabric.
Advantages: provides controllable ventilation
Disadvantages: Heat loss, requires space for ducting, might be quite noisy if the unit is installed not properly.

Mechanical ventilation with heat recovery

Mechanical ventilation with heat recovery (MVHR) - the same as the MEV, the MVHR should be installed into all 'wet' rooms. Both systems work very similarly, only before passing through the outlet the moist air goes through exchanger, where the heat is transferred  to the fresh air which is ducted to the other rooms.
Advantages: Provides controllable ventilation, reduce heat loss, provides air filtration
Disadvantages: Expensive, complex installation which requires a lot of space, filters needs to be changed regularly, requires a high lever of airtightness.




Case study

Greenwatt Way - zero carbon house with integrated natural and mechanical ventilation.

Natural ventilation - roof opening and windows with large openings helps to drawn warm air out of the house during the hot summer time, when overheating becomes an issue in highly insulated dwellings.

Mechanical ventilation - in order to preclude natural/passive ventilation and heat loss the mechanical ventilation with heat recovery system was installed.

References: 

'Greenwatt way' [Online] Availabe at: http://www.thisisconcrete.co.uk/home_page/case_studies/greenwatt_way.aspx [Accessed at 17th of November, 2013]

‘Greenwatt Way. A zero carbon homes newbuild case study’, 2011. Energy saving trust.

 ‘Greenwatt way’ [Online] Available at: http://www.house-builder.co.uk/documents/WILFORD-Chris.pdf [Accessed at 17th of November, 2013]

Richards Partington Architects, 2012. ‘Understanding overheating – where to start’ NHBC Foundation

Zero Carbon Hub, ‘Overheating in homes’ [Online] Available at: http://www.zerocarbonhub.org/resourcefiles/OverheatingInHomes8pp_2013_8March.pdf [Accessed at 17th of November, 2013]

Zero Carbon hub, 2013 ‘Mechanical ventilation with heat recovery in new homes’ NHBC Foundations

Building Regulations, Approved Documents Part F, 2010 [Online] Available at: http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partf/approved [Accessed at 17th of November, 2013]
'Different types of building ventilation'[Online] Available at: http://www.wisegeek.com/what-are-the-different-types-of-building-ventilation.htm [Accessed at 17th of November, 2013]

UK Planning guidance

Before beginning any construction work, it is required to get a planning permission. For this it is essential to provide planning application, access and design statements, etc. Without having any of these documents, there is no possibility to begin the development.The UK Planning guidance would be very helpful when preparing all the paper work.

Planning Portal is the Government's official website for planning and building in England and Wales; In which people can find planning applications, search common building projects, read the latest policies and news or download building regulations. Thus, everyone who is responsible for the construction process has to be introduced to this website.

Life Time Homes

Buying a house is one of the most important purchase in our life. The reason is not that it might be the most expensive thing we have bought but because it will be home for us, for our children and maybe grandchildren. That is why nowadays many houses are designed to be flexible and accessible such that the house could adapt to the life changes.

To meet a lifetime home standards you have to follow the main 16 criteria:

1. Parking (width or widening capability)
2. Approach from parking to dwelling (distance, widths, gradients)
3. Approach to all entrances
4. Entrances
5. Communal stairs and lifts
6. Internal doorways and hallways
7. Circulation space
8. Entrance level living space
9. Potential for entrance level bed-space
10. Entrance level WC and shower drainage
11. WC and bathroom walls
12. Stairs and potential through-floor lift in dwellings
13. Potential for fitting the hoist and bedroom/bathroom relationship
14. Bathroom
15. Glazing and window handle heights
16. Location and service control

There is some photos of Lozzells (Birmingham,UK) residential development where few of the 16 requirements had been already applied for the construction.

Knock out panel on the floor for future provision for a lift

The entrance level WC with the potential for a shower to be installed and grab rails to be fixed.

It was calculated that the cost of building to the Lifetime Homes standards range from £574 to £1615 per house.

Most of the 16 Lifetime Home criteria are related with Building Regulation Approved Document Part M. However not all of them match with AD Part M standards. An additional design features should be added to satisfy some of the criteria.

References:
'Lifetime Homes' [Online] Availabe at: http://www.lifetimehomes.org.uk/ [Accessed at 18th of October, 2013]
Images:
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