K12AE3 Exam paper 2015-16 UPDATED V2.pdf A south-facing medium-weight mid-terraced house is 6m wide, 6m high, and 10m deep. It is located in London...

K12AE3 Exam paper 2015-16 UPDATED V2.pdf

A south-facing medium-weight mid-terraced house is 6m wide, 6m high, and 10m deep. It is located in London where there are 1800 heating degree days per year. It has 3 windows and 1 door located in both the front and rear façades. Each window is 1m wide by 1m high and each door is 1m wide by 2m high. Its fabric has U-values (W/m2/K): walls 1.5; windows 2.0; doors 3.0; floor 5.0; roof 0.5. Under its floor is a crawl space whose air can be considered to be at ambient temperature. The mean ventilation rate is 2 air changes per hour. It has a permeability of 15m3/h/m2. Its 11kW boiler runs for 16 hours per day to maintain a comfort temperature of 18.5 C. Average casual heat gains are 1kW.

(a)  Calculate the fabric, ventilation, and whole building thermal conductance.

(b)  Estimate the percentage of time per year that the boiler can provide the required heating load. 

(c)  Discuss the purpose and validity of a standard blower-door test conducted in this house.

(d) Discuss pollutant sources that might be found in this house that are attributable to occupant behaviour and methods of mitigating any harm they may cause occupants.