Ducted system for house

[Lc_shi]

Hi dear sirs
One 300m2 house air conditioning. If we apply constant air system, how to do when some room turn off air conditioning ,for the air volume is constant and compressor is constant capacity? If we need to set VAV system , the cost should be high (for vav box and inverter compressor). How about your idea?

thanks and regards
LC

[OAT99]

hows about a dual zone digital controller, far less expensive than a vav. You can have multi zone (room) control, you can even set it up to have an economizer for that evening breeze (free cooling). be sure to filter your intake air.

[Abby Normal]

you either over supply air to the rooms still calling for cooling or you bypass air to the return side

[Lc_shi]

I mean while the room cooling or heat load decrease, the non-inverter compressor can match the indoor unit or not. Anybody can offerme some clues?

[Brian_UK]

A non-inverter compressor can only provide a fixed duty.

[Peter_1]

In these systems, you bypass controlled cooled pulsion air back to the extraction plenum so that the load on the evaporator drops and the airflow over the coil remains the same.
Anyhow, if you want to shut off some zones, a watercooled coil is a much better solution because you can keep ductpressure at a constant level without having problems of icing up the coil when decreasing the fan speed.
A VAV system with a non-inverter compressor is a bad energetic solution. But it can work with a bypass but far from the same comfort level of a cooled coil or an inverter driven system.
Look once at http://www.twitoplast.co.il/eng_cata...0System&step=1
It was mentioned in the latest RACA Journal of South Africa

[Lc_shi]

A VAV system with a non-inverter compressor is a bad energetic solution?

It make me think more about it. Any investigation on it?

[Peter_1]

A VAV system with a non-inverter compressor is a bad energetic solution?

It make me think more about it. Any investigation on it?

LcShi, you will load artificially the evaporator to match cooling load with actual load. Also fan speed is higher then really needed when running in partial load.

[Lc_shi]

how about it if fan speed can be multi-velocity or variable ?