Engineered Services Co-Operative, LLC

I first used them in 2012.

I would give them a good referral! Excellent! Workers were very professional.

Probably one of the most professional companies I have ever dealt with.  I am pretty nit picky, and they exceeded my expectations.  My system has been in four years now, and has worked very well.  I have seen in many newly constructed homes where the HVAC contractor would use a fiberboard main duct with flexible hoses running off of it to the registers in each room.  Engineered Services uses all metal duct work through out, and then spay foamed every bit of it to boot!  They use the "Water Furnace" brand of geothermal which is the top of the line.
At the 3 1/2 year mark, we had a problem when our A/C quit and the thermostat screen turned red and had a message something to the effect of "Call For Service."  Of course, it was on a Saturday when the company was closed.  I went ahead and called anyway and left a message.  Evidently they have message forwarding, as Richard, the owner, called me back within 15 minutes and was able to rectify the problem over the phone.

When the said he was coming, he was there. He gave me a price, and that's what he stood by. He's very nice and personable. He does quality work.

How is it possible these guys have no previous recommendations on this site? Talk to them and you'll be impressed. Talk to their reference clients and you will be overwhelmed.
They were professional, knowledgeable, punctual, neat, competent, gentlemanly, responsive, hardworking and cooperative (guess that last was in their name). They figured out the best way to get the job done at the best price, even when it meant less money for them.
All work was square and picture perfect. If you don't like something, they'll fix it so you do (within reason I guess). What more do you need to know?
If they were average I would tell you that, but they were exceptional.