Jenny Robinson left a comment on our blog to ask if it would be possible to heat a Passive House with cats…
So we thought we would check to see how many cats would be needed…
They cited the example of The Countess of Groan in Titus Groan surrounded by a sea of white cats in her castle, but what if we were to employ modern Passive House standards?
According to CIBSE Guide Volume A; Design Data Table A7.3, pA7-4
“… a 3kg cat has a heat output of 14.8 Watts.”
To comply with Passive House Standards, a building must have an annual heating demand as calculated with the Passivhaus Planning Package of not more than 15 kWh/m² per year in heating**.
If we assume a house of 150m2 the total heating load per annum is:
15kWh/m² × 150 m² = 2250kWh
The number of cats required is therefore:
2250kWh / 129.65kWh = 17.35 cats
It is probably best to round up to
18 whole cats to avoid complaints.
This equates to 1 cat per 8.33m².