air handler's ratio of outside air to supply air
air handler's ratio of outside air to supply air
(OP)
In designing a split system i have been informed that the percentage of the outside air in the supply air should be less than 22%. I am assuming that this allows the system to perform accordingly without overloading its cooling and heatingm, but thats just an assumption. I don't have any concrete reasons for this method of designing a split system. Does anyone have an answer?





RE: air handler's ratio of outside air to supply air
A typical system will increase outdoor air when CO2 levels rise to 600-800 PPM to insure that maximum levels do not exceed 1,000 PPM. The system should incorporate a minimum outside air setting to dilute building related contaminants during low occupancy periods. A drawback is that CO2 sensors must be calibrated periodically and setpoints may need to be adjusted based on outdoor CO2 levels around the building.
RE: air handler's ratio of outside air to supply air
RE: air handler's ratio of outside air to supply air
You can get very expensive controls and equipment that will minimize but not eliminate coil freezing problems.
RE: air handler's ratio of outside air to supply air
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air
For those who cautioned about coil freezing, please elaborate. Are you saying that the ambient (i.e. the entering air) temp could be so low that suction pressure will fall and cause the coil to freeze?
RE: air handler's ratio of outside air to supply air
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air
RE: air handler's ratio of outside air to supply air
Stainless clamshell on 100% outside air is a waste of money.
My days of 40 below and 4 feet of snow ended 8 years ago
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air
I've seen premature failures with aluminzed steel HX and high O/A loads.
It is currently a balmy -26C (-15F) and we're expecting another couple inches of snow...
Everytime I read your warm weather posts Abby I think: sure I could move, but what would I do with all this cold weather design experience? And then the weather drops another few degrees and I think: I wonder if Abby needs a partner?
RE: air handler's ratio of outside air to supply air
Vapour barriers, condensation are all the opposite of the north.
I have been recruitting by the way.
The comment was on the heat exchanger design of the cheap packaged unit HX or even a stainless steel ICES clam shell. Compare it to something by EngA, drum, tubes, less thermal stress and a condensate drain.
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air
RE: air handler's ratio of outside air to supply air
www.hpac.com
RE: air handler's ratio of outside air to supply air
ht
RE: air handler's ratio of outside air to supply air
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: air handler's ratio of outside air to supply air