Garage A/C control system.

[Shaggy]

Hello 

I've been following the blog for a while now and decided to finally join up!

I'm working on this project at the moment.. but I'm sort of stuck. I love electronics but I'm no expert yet. xD

Alright, so I'm making a control system for a DIY A/C project for my garage. (The heat out there is insane, I could probably melt solder to the wall just with air!) I know how I want the system to work but I'm just not sure how to make a circuit board/control module. Basically I have a refrigerated water cooler I plan setting up to run cold water inside the garage to a fan/radiator to cool it down.

Here's what I have so far. (sorry if this is a poor diagram, don't have money for a good diagram program.)




What the diagram means: Basically I need to find a way to delay start up of components, the water circulation pump needs to start approx. 1-2 minutes after the compressor turns on. The compressor needs to turn on 30 sec. after the cooling fan turns on. How can I make a time delay circuit? (It'll actuate a relay/contactor for each part)

Second problem is the thermostat type of control circuit. I could just get a normal thermostat but that's not part of the DIY spirit. xD

I just need something that will turn a relay on/off and a settable temperature. This relay will actuate the time delay circuits which will actuate the components.

This is probably an extra elaborate system but the more complex it is the more fun it is in my opinion!

[lamja]

An Arduino will be perfect for this project. You can use a temperature reader and some logic-level FET's to control your releys.

Even easyer: If you don't want relays, like this guy did with an Arduino and some servos :

[Pyr0Beast]

I am not sure why do you want to complicate things.

Cooling fans can be started with compressor. You could just add a simple bimetal switch to start compressor when water temperature gets above a certain threshold, same for the pump it could run with fans-radiators in the garage.

If the compressor is any less than 500W just forget about cooling the garage down.

[Shaggy]

Well, the way I was designing it was so the fan cooled the compressor before start up (Seeing as its 100 degrees out here and this'll be outside.) But I've since changed the plan, now the fan runs all the time and the compressor gets cooled by a separate system. Now the compressor will have a 5 minute anti-short cycle delay and the pump will turn on the same time delay as before.

I don't really intend to keep the garage at 70 degrees, just something less than 100 would work good. I've tested it with a "small scale" radiator and fan and it seems to have plenty of cooling power to spare.