Carrier ICS FE4 Air Handler With Water Coil?

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08-05-2010, 02:57 PM
DavidNJ

Carrier ICS FE4 Air Handler With Water Coil?

Carrier apparently sells both the coils and the a hydronic interface. The ICS apparently has hybrid heating with hot water available.

Has anyone done it?

For a small system it offers lots of modulation: a 60mbtu boiler can modulate to 16mbtu. The outdoor reset on the boiler would also manage the modulation. Could mixing also be done to control modulation, especially with zoning?

Setup -- Hydronic Heat
HYDRONIC HEAT SETUP

HOT WATER LOCKOUT -- Outside temperature above which the hot water will not operate except for defrost (if needed).
S Available settings -- NO, 5 to 55_F / --15 to 13_C in 1_increments
HEAT PUMP LOCKOUT -- Outside temperature below which only the hot water will run, 1_F / .6_C resolution.
S Appears only with a heat pump outdoor unit.
S Available settings -- NO, 5 to 55_F / --15 to 13_C in 1_increments
DEFROST W/WATER:
S Available settings: YES / NO (Default =YES)
S Appears only if heat pump is available If no, hot water will not run during a defrost.
AIRFLOW -- Selects desired airflow during Hydronic Heating S Available range from OFF, 500 CFM(minimum) to 400 CFM/ton cooling maximum in 50 CFM increments.
S Default is the cooling airflow. (350 CFM/ton)
S OFF selection does not turn off airflow if heat pump is defrosting.
BLOWER ON DELAY -- Time after hot water is requested that the blower will turn on.
S Available settings -- 0 to 240 seconds in 30 second increments
S Default is 30
BLOWER OFF DELAY-- Time after hot water request terminates before the blower will turn off.
S Available settings -- 0 to 240 seconds in 30 second increments
S Default is 0.
08-05-2010, 11:36 PM
DavidNJ

Still looking for someone who used it with a boiler.
08-06-2010, 12:05 AM
tedkidd

David, I looked at it. Wouldn't do what I wanted. Boiler does not communicate with air handler, definitely won't ramp up or down for zoning. Consider that.

Want fast recovery when not real cold? Ts, outdoor reset only allowing 120 f water. Boiler doesnt know what ah is trying to do. Is this a big deal? Probably not, but mvc would know and deal with that.

Other option- run hi temp water all the time. What's the point of that!!
08-06-2010, 01:01 AM
DavidNJ

Outdoor reset would probably be 85F-140F. It wouldn't know about zones but would know about EWT. It would also keep air volume up during heating which the MVC can't do.

However, no dehumidification with reheat, which is a water advantage.

Isn't the coil placement in the FE4, before the blower, better than the MVC, after the heat exchanger?
08-06-2010, 10:44 AM
drewski11

Quote:

Originally Posted by DavidNJ

Outdoor reset would probably be 85F-140F. It wouldn't know about zones but would know about EWT. It would also keep air volume up during heating which the MVC can't do.

However, no dehumidification with reheat, which is a water advantage.

Isn't the coil placement in the FE4, before the blower, better than the MVC, after the heat exchanger?

the DX coil is before the blower. the water coil would go where the heat strips usually do, which i'm pretty sure is after the blower. at least that's what i was told.

why is before better? impact on static?
08-06-2010, 11:17 AM
DavidNJ

Quote:

Originally Posted by drewski11

the DX coil is before the blower. the water coil would go where the heat strips usually do, which i'm pretty sure is after the blower. at least that's what i was told.

why is before better? impact on static?

All of the commercial air handlers I've looked at have had both cold and hot water coils before the blower. All the residential air handlers have the DX coil before the blower.

The question is why they do and why furnace systems don't.
08-06-2010, 02:44 PM
drewski11

Quote:

Originally Posted by DavidNJ

All of the commercial air handlers I've looked at have had both cold and hot water coils before the blower. All the residential air handlers have the DX coil before the blower.

The question is why they do and why furnace systems don't.

my understanding is that if the DX coil was before the heat exchanger it could cause condensation and possible corrosion in the exchanger.
08-06-2010, 02:54 PM
DavidNJ

The DX coil is AFTER the heat exchanger which is after the blower on a furnace. It is before the blower on an air handler. On some (most) air handlers, the hot water coil is between the cold water coil and the blower.
08-06-2010, 03:06 PM
drewski11

Quote:

Originally Posted by DavidNJ

The DX coil is AFTER the heat exchanger which is after the blower on a furnace. It is before the blower on an air handler. On some (most) air handlers, the hot water coil is between the cold water coil and the blower.

Yes, my answer was WHY it's after the heat exchanger and the blower in a furnace. If it was before the blower and heat exchanger the cold air could cause condensation and corrosion in the heat exchanger. This is not an issue for the hot water coil so it can be downstream of the cooling coil.
08-06-2010, 05:14 PM
DavidNJ

ok...that makes sense.

Then why is it before the blower in the other cases. That is, what advantage is there when a furnace isn't used that is lost when a furnace is used?
08-06-2010, 05:37 PM
drewski11

Quote:

Originally Posted by DavidNJ

ok...that makes sense.

Then why is it before the blower in the other cases. That is, what advantage is there when a furnace isn't used that is lost when a furnace is used?

What I've read is that with the furnace + heat pump, you can't run the heat pump and have the furnace augment the heat (i.e. run them simultaneously) because the air from the heat exchanger will be at a higher temp than the heat pump can produce. If the heat pump starts to struggle it shuts off and furnace is 100%.

With an air-handler heat pump + aux heat (strips or water coil), both can be run together so the aux heat can supplement rather than take over for the heat pump.

There may be other reasons.
08-06-2010, 06:35 PM
DavidNJ

However, if there is only a heat pump, such as the AHUs from Mitsubishi and Fujitsu, the coil is before the blower. When manufacturer's report the SEER/EER /HPSF/COP of air conditioners and heat pumps, the air handlers always have better numbers than the furnaces. Is that just the extra air flow constriction of the furnace heat exchanger?
09-23-2010, 10:43 PM
Love_Geo

I have this setup installed in my home. I have a Carrier GT-PX Geothermal Heat Pump, FE4 air handler with Infinity Controls 4 zones, HWG, and the hot water coil hooked to my boiler. The boiler also supplies domestic hot water as well as hydronic heat. (2 separate water circuits) I have had the boiler for 14 years using it to supply water for 4 Aquatherm systems.

According to the Carrier rep, there are only 3 homes in the US with this setup (Geothermal, Hydronic Supplimental). Mine, 1 in Washington State, and 1 in Indiana.

I saw a post on here about the call for the boiler to come on. Since mine also supplies the hot water for the house (limitless) it has a upper and lower limit built into its controls. 120 degrees lower, 180 upper. The boiler operation is self contained and does not require controls from the unit.