Help w/ design for brew rig.

I have been all-grain brewing for a couple years now on a pretty simple 2 tier gas system. I'm very interested in moving into the electric design and I think I've got a great location for it in my garage with a 240v source that I can have an electrician wire up for me. I have some questions as to if what I'm envisioning will work well. I brew almost exclusively 5 gal batches but like having the flexibility of being able to handle a 10 gal batch if I decide I want to.

I'm not interested in totally automating my brewing experience. I don't mind switching hoses around and monitoring temps some. The whole Kal system looks super cool, don't get me wrong, but I don't have the expertise or care to spend that kind of money to build something that pimped out. I'm thinking more of having a HLT that I can just dial in a temp and have it held at that temp automatically. I use batch sparging and would like to keep it that way. I'm thinking about a totally insulated keg-MLT that I can just mash in and come back at the end of the 1 hr mash and drain to boil kettle. Finally, an electric boil keggle. I'd like a single tier, 3 vessel system (I've already got a pump.)

Here are some of my questions:

1) Will a completely insulated sanke keg-MLT hold mash temps for an hour without any sort of HERMS or RIMS setup?

2) Can I build what I'm envisioning pretty inexpensively?

3) Do I need 2 pumps to run this type of system or can I do it with 1 pump?

Would appreciate any and all comments/suggestions and answers to my questions.

Thanks

So here are some answers...
1 - Depends on how good your insulation is. You can expect to have some degree of loss, but I've heard of people only getting a degree or two loss in a 12-14lb mash. So, yes - you could stay pretty close to your initial temp with the right degree of insulation.

2 - Assuming you are only asking about building the electric part - you have a decision to make. You can get a PID and a temp probe, and the PID will turn your element on and off to reach and maintain a temp. Or you can buy / build a PWM that you use to manually adjust the amount of power sent to your heating element and you have to monitor the temperatures and adjust. The PWM route is cheaper. The PID, a small case, a temperature probe, the SSR, and all that can be had for probably around $150.

3 - If you batch sparge, no. You can pump all your water from the HLT to the MLT, then reconfigure the pump to go from the MLT to the BK.

-Kevin

When doing the electrical work, you want a minimum 240v/30amps with GFCI. If you want to run two vessels at the same time then you need 240/50amps.

I spent about $300 on an eBIAB (single vessel) control panel including wiring, heating element, power cords, etc. The same control panel can also be used for your boil kettle.

What is a PWM? I guess I'd rather not have to monitor the temp of the HLT. I like being able to just set and forget the HLT. I guess that's the only automation that I would want. I guess $150 isn't bad. I can deal with that. Any other bits of advice? Where can I buy these electrical parts?

Theelectricbrewery.com is a high end control panel build but also has detailed parts lists with sources for each part. I orders most of my parts from amazon and ebrewsupply. Auberins is another popular source for pids.

If you insulate the hell out of the keg, preheat properly, then you can let it ride without HERMS/RIMS. The easiest setup I could imagine would be to build a controller with an Auberins.com PID with manual mode, a 40a SSR, and put it in a box. Mount the temp sensor in the HLT. Have the control box have a 30a outlet and then you can switch which vessel's element gets plugged in (HLT or boil kettle). When it's time to boil, plug in the BK element and set the PID to manual mode for the boil. Slightly mo better would be to put a 30a DPDT switch in the box to select which element is being fired.