I just purchased a Stirling Technology RecoupAerator 200DX that I'm trying to decide how to control. For those that don't know, an ERV is basically a heat exchanger that allows you to replace stale air in your home with fresh air from the outside. It retains the temperature and humidity of the inside air and transfers it to the fresh incoming air. In the summer, the heat and humidity from the fresh outside air is "diffused" into the stale outgoing air. In the winter, the heat of the stale air going out is exchanged into the incoming fresh air.
The unit features 2 variable speed blower motors (GE ECM), one for stale air out, and one for fresh air in. A third motor drives the energy transfer wheel/filter. I'll duct the unit into my existing HVAC (Trane XE 90) air return and interlock the two together so that the ERV only runs when the air handler blower is on.
The 200DX ERV features a low voltage control PCB with the following connections:
0-10VDC fan control input: Allows adjusting the air exchange with the outside air from 70-210 cfm. 1V = 70cfm, 10V = 210cfm. <1V fans off.
Normally the unit runs in balanced mode, that is the in and out blowers run at the same speed. However, the out blower can be throttled back to create positive pressure in the house to prevent moisture from entering wall cavities, etc. A differential pressure transducer can be connected to the control PCB to retard the out blower motor to maintain neutral or slightly negative pressure.
EconoCool: Bypass air exchanger to allow cool air into house when inside is calling for cooling. This eliminates the need to run the A/C and is very usefull during the night and mornings as long as the outside humidity is low.
I would like to control my entire HVAC/ERV from my computer. I envision needing indoor and outdoor temp and humidity sensors and the ability supply a 0-10 VDC signal to the 200DX as well as provide a contact closure for the EconoCool feature based on the outside temp and humidity, in addition to the the normal closures for the HVAC (fan, heat and cool).
As for the interface to the computer, I was thinking that the following items would do the trick:
1 Midon MD2104 (TEMP08) rs-232 interface
2 Midon MD3020E temp/humidity sensors
1 Midon MD2083 4 channel relay board
2 Motorola MPXA4115 pressure sensors (will need additional support electronics)
I still miss something that will allow me to supply a 0-10VDC control voltage.
But other than that, does this sounds like a doable design? Should I be looking at different hardware?
I already have a computer mounted in a rack with a UPS and a backup generator controlling a 400 gallon reef tank, and it is very reliable, which of course is needed in an application that won't have a regular thermostat as a backup in case something goes wrong.
The unit features 2 variable speed blower motors (GE ECM), one for stale air out, and one for fresh air in. A third motor drives the energy transfer wheel/filter. I'll duct the unit into my existing HVAC (Trane XE 90) air return and interlock the two together so that the ERV only runs when the air handler blower is on.
The 200DX ERV features a low voltage control PCB with the following connections:
0-10VDC fan control input: Allows adjusting the air exchange with the outside air from 70-210 cfm. 1V = 70cfm, 10V = 210cfm. <1V fans off.
Normally the unit runs in balanced mode, that is the in and out blowers run at the same speed. However, the out blower can be throttled back to create positive pressure in the house to prevent moisture from entering wall cavities, etc. A differential pressure transducer can be connected to the control PCB to retard the out blower motor to maintain neutral or slightly negative pressure.
EconoCool: Bypass air exchanger to allow cool air into house when inside is calling for cooling. This eliminates the need to run the A/C and is very usefull during the night and mornings as long as the outside humidity is low.
I would like to control my entire HVAC/ERV from my computer. I envision needing indoor and outdoor temp and humidity sensors and the ability supply a 0-10 VDC signal to the 200DX as well as provide a contact closure for the EconoCool feature based on the outside temp and humidity, in addition to the the normal closures for the HVAC (fan, heat and cool).
As for the interface to the computer, I was thinking that the following items would do the trick:
1 Midon MD2104 (TEMP08) rs-232 interface
2 Midon MD3020E temp/humidity sensors
1 Midon MD2083 4 channel relay board
2 Motorola MPXA4115 pressure sensors (will need additional support electronics)
I still miss something that will allow me to supply a 0-10VDC control voltage.
But other than that, does this sounds like a doable design? Should I be looking at different hardware?
I already have a computer mounted in a rack with a UPS and a backup generator controlling a 400 gallon reef tank, and it is very reliable, which of course is needed in an application that won't have a regular thermostat as a backup in case something goes wrong.
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