Using correct ventilation to ease the discomfort of respiratory disease

Poor house ventilation can cause great discomfort.

It is a well known fact that the environment we live in can have a major impact on our health and general well being.  A poor environment certainly caused problems for one of our elderly clients and we were pleased to assist in improving things for them.

Our client lives in a three bedroom, three floor house which has a conventional attic.  There was a whole house supply and extract ventilation system installed, which extracted from two WCs, the kitchen and bathroom.  However this system did not conform to building regulations, with extract rates below the required rate at less than 15l/s.  Nor did it conform to the current fire regulations as the ducting between different rooms were without firebreaks.  A further problem was that the resident dust was readily carried from room to room and was visible coming through the extract grilles in the ceiling.

Flexible ducting had been used in the attic.  Using flexible ducting can present a number of problems if it is not installed properly.  In this case it was of excessive length and during the installation it had been squashed in places.  To make things more complicated the ducting runs were not accessible within the ceilings.  The result of this poor installation and the uneven nature of the flexible ducting made the passage of forced ventilation challenging, as the surfaces produced turbulence that resisted air flow which in turn created greater back pressure.

Not only was the impact on the householder increased cost as a consequence of higher energy requirement and noisier air movement, but also the main concern in this instance was due to the dust that had accumulated in the duct runs (dust/particular condensate).  Due to the turbulent air flow characteristics of the ducting, the air readily gave up its contaminated content within the ducting as each turn of air caused the air to become thinner and less able to retain particular matter.

The occupant was in hospital being treated for a serious respiratory disease and had been complaining that the home environment was both stuffy with that there was lots of dust exacerbating their health problem.

The solution was to remove the existing system fan and ducting from the attic and seal and make good the ceiling grilles in the bedroom, kitchen and lounge.

The occupant spends most of their time in the sitting room and bedroom and in these rooms we installed a filtered simultaneous intake/extract (DRYVENT X) fan through the wall at high level.  This fan system runs continuously providing filtered fresh air and extracting stale air.  This is highly effective because the plume of air in the front of the fan is essentially fresh air.  With low constituent vapour pressures, the internal air constituent readily migrates to this area as it establishes an equilibrium “high vapour pressure going to low vapour pressure”

Independent fire safe fans (OTTER Fire safe) with internal intumescent seals were installed in the internal bathroom and two WCs.  These operate from the light switch and have a proportional timer overrun.

And to provide the correct ventilation in the kitchen we installed a WOLF K automatic fan with  filter which we fitted through the wall.

The RHL solution now provides a comfortable sustainable healthy environment with a cleaner oxygenated atmosphere. The benefit to the householder is marked and upon return from hospital they are delighted with the cleaner atmosphere, significant reduction in dust and the air feeling less “tight”.

Not only have we improved the general living conditions for this person, but as an elderly person on a limited budget, another concern was related to minimizing costs.  We installed energy efficient fans which together only cost an estimated £9.92 per annum in electricity charges. This was significantly cheaper than the original system. (calculated on an assumed 4 hours average use of each of the internal and kitchen fans and  two continuously running DRYVENT X fans).  Detailed fan specifications together with the energy requirements can be found on the product data sheets.

Example Calculation

Assumption: The fans in the bathroom, 2 WCs & kitchen run intermittently, with the average running time for these types of fan systems being 4 hours in any 24 hour period

In one year this = 365 x 4 = 1460 hours each

Kitchen:   WOLF K @ 8 watts

Annual power requirement: 8 x 1460 = 11.68Kwh (kilowatt hours)

Bathroom & 2 x WC: OTTER Fire Safe @ 4 watts each x 3 = 12 watts

Annual power requirement: 12 x 1460 = 17.52Kwh

Lounge and bedroom: 2 DRYVENT X @ 2 watts = 4 watts continuous running

Annual power requirement: 365 x 24 x (2 x 4) = 70kwh

Total Annual power requirement: 11.68 + 17.52 + 70 = 99.20 Kwh

Electricity cost is generally between 6 – 9p/kwh.

However assume 10p/Kwh

99.2 x 0.1 =  £9.92 Annual running cost for the 6 fans

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