Full fresh Air Package unit

[Goober]

Hi all,

I have a customer that requires a full fresh air package unit to replace an Australian Techniaire unit that has come to then end of its useful life. Local supplier Temperzone can't handle a custom unit like this. This is more directed at my Australian colleagues...the specifications are as follows...ignore the separate exhaust part, that is already in place

It is for a Biologically secure facility similar to a dust free area which requires filtered fresh air input and a separate exhaust system maintaining the space pressure at 20 pa below ambient. the minimum airflow is 120l/sec and ideal max is 200l/sec. Cooling requirements is to maintain space temp. at 20 deg C with an ambient air temp. of 32 deg C with an RH of 75% allow for a 2kW solar, lighting and electronic gain
The winter cooling requirement is to maintain a space temperature of 22 deg C with an minimum ambient temp. of 0deg C and a RH of 60%. As the operation is 24/7 the is a need for hot gas bypass deicing of the outside coils in heating mode. we can consider aux electric resistance heating for preheat in low temperature conditions with a maximum of 7kW

Anyone know a supplier that would have a unit to suit?

[Magoo]

Hi Goober.
that was snap quick response, cheers bud, catch up tomorrow. Should not be a problem at all.

[Mick13]

mate theres a company called airchange that make a unit that would probably fit what u need.

they are based in sydney i believe, i have worked on a few of them before, they make 100% fresh air units, and run the return air (exhaust air) through a heat exchanger with the fresh air before its cooled, to precool the air to save energy costs, if u get what i mean.

so if the air in the conditioned space is 22c and the air being taken in from outside is 32c, it runs them through a heat exchanger to precool the air intake to say 27c-28c before it hits the cooling cool to reduce running costs.

i personally think its a really good design.

[chemi-cool]

Check this website, they make very good products.

http://www.addison-hvac.com/

[icemanpaj]

Hey mate,
At a previous job we worked on heaps of these 100% OA units, when it came time to replace them we installed some Accent Air Package units that have digital comressors. so they ramp up and down depending on the load in the lab. We were able to maintain +/- .5deg c. We also installed 3 wonderful Temperzone digital units before they discontinued them. For the winter we used to use electric reheats and carel humidifiers to maintain RH. Also on bigger clean rooms we used chillers and Temperzone AHU's and electric reheats. I don't know about your lab situation but they used to come to us with the spec sheets and 'forget' to include the Fume Cupboards, so we'd size it all up then have to alter the units again to adjust the airflow volumes.