single coil

[yazguli]

Hi every body
If there is no need to have cooling and heating simultaneously and if there are control valves on air handling units ,is it enough to have just a single coil for both heating and cooling?

 

[dbill74]

What you describe is done all the time, they are "heat pumps". Frequently used in residential applications in moderate weather zones.

 

[RossABQ]

I'd assume from the "control valves" mentioned that you are talking about a hydronic unit? The size and characteristics of a coil for cooling is not likely to be suitable for heating, in a hydronic system. Depends on your water temps for heating, tho.

 

[yazguli]

RossABQ ,
It's a hydronic unit and I mean a three or two way motorized valve.I think it may be possible for a control valve to regulate flow rate for both of heating and cooling , for example both 10-20 and 10-40 gpm.Of course it seems to me that a more accurate analysis is necessary.

 

[yazguli]

And of course we assume that the coil is selected to meet the cooling demands.

 

[willard3]

It is called a two-pipe changeover system and it works badly but keeps piping costs down.