Ventilation - Air-conditioning

Ventilation - Air-conditioning


For 29 years we used thermostatically controlled storage heaters and since our bungalow is airtight and very well insulated, the running costs of storage heating was reasonable.

However, in 2018, we removed all the storage heaters and had a 7.5kW air-sourced heat pump fitted driving two ceiling cassettes and a wall unit. 

We used this system for the 2018-19 winter with two ceiling  cassettes in the main hall, but they were not quite sufficient to heat our bungalow.

So, in 2019, we had an additional 5kW air-sourced heat pump fitted to heat and cool the lounge and provide additional heating to the bedroom area.

We had tried a stand-alone portable air-conditioner, but it was incredibly noisy and needed a huge snakey hose.


5kW Heat Pump

By having two air-sourced heat pumps, we have redundancy and back-up should one of the units fail.  However, we need both heat pumps running concurrently when the weather is exceptionally hot or cold.

It is worth noting that a 7.5kW unit uses a maximum of 2.5kW because of the 3:1 efficiency ratio.

We are on the Octopus Energy GO tariff that offers cheap electricity for four hours, to fully charge our Tesla Powerwalls and electric cars.  The Powerwalls then release the stored charge during the day when the price of electricity is dearer, so saving us a considerable amount of money.  If you would like to join Octopus (who have excellent customer support), please use this Octopus Link to give yourself and I, a £50 bonus. 



Ventilation and air-con controllerIn the photo on the left, the black left display controls the forced ventilation and heat recovery system; this ensures that the bungalow has sufficient air changes per hour to avoid condensation.

The white unit on the left is an air conditioner controller.  It is worth noting that air conditioning does not replace air, the ceiling units either heat or cool the existing air.

The white controller can use four programmes for each day of the week, and we use all four.



Ceing air conditioning cassetteThis is a typical ceiling air conditioning cassette.  Air is sucked in through the centre where it is then heated in winter or cooled in summer and then blown out through the four vents on the edges.

This is a 2.5kW unit, but, because of the 3:1 efficiency ratio, it uses a maximum of 800W of energy.  Except for the lounge and main bedroom, no rooms have individual heaters.

The ventilation system brings fresh air into the bungalow and also provides air movement, and so avoids the use of individual room heaters. 


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