two zone split heat pump question

[ghnl]

I am looking at options for heating/cooling our remodelled garage. I asked a local HVAC company about a dual mini-split system with one unit for the garage & the other unit in a 'bonus' room over the garage. His answer confuses me (and I didn't think this through until after he'd left...). He was reluctant to sell me such a system "in case there was a problem in the garage you wouldn't want it to vent into the room above." Am I correct in assuming that they'd be no way for the heat pump to allow something like vehicle exhaust in the garage to get into the room above?

I've done some reading on line (here and at some Mini-Split websites) but I am still unsure if it would be doable to use a dual zone mini-split for the two different areas or not. I did read a caution on one company's web site about not trying to run only one unit with their dual zone heat pump - something about excessive return pressures could result in damage. But can a dual zone mini-split system run two separate wall units at two different temperature settings? Or would I be better off getting two separate mini-split systems?

I am also looking at "PTAC" units but the quieter operation of the mini-split has a definate advantage. Or maybe a PTAC for the garage and a mini-split for the bonus room...

 

[TheShrine]

I don't understand his "venting" issue either..it doesn't make sense...other than him being overly concerned with the coolant escaping and...who knows!

Anyway, I just installed two different splits in my garage. I considered a dual zone but decided on two different units. I had no codes to consider, and I had the outside mounting space that was concealed and well vented, and it was cheaper! There was also the issue that one compressor (heat pump) for two different cooling units meant that ultimately both areas of cooling was down if the compressor had issues.

Check WEB pricing, you should find the same deals right now. BTW, I bought mine from a WEB provider and hired a local A/C company to install to maintain the warranty.

 

[ghnl]

Back with more questions about ductless mini-split systems.

Anyone install one themsleves? I'm getting some estimates from local HVAC companies which are 2X's - 3X's what I would spend if I bought it 'on-line'. (One on-line outfit even claims "no vacuum needed - lines pre-charged".) I don't mind the local contractor making a profit but these estimates seem quite high to me.

Also, does the interior unit have to be located on an exterior wall? I'd like to locate the inside unit on a wall beside a staircase. The pipes could then run under the stairs to an exterior wall.

 

[rickairmedic]

Eric I am doing 2 1 ton heat pump units for another member for $3532 kick in an extra $500 for travel and I hook ya up You can put th inside unit just about anywhere you like although outside wall is prefered just means longer lineset.


Rick

 

[checkthisout]

He was confusing a heating system with zone control VS the mini-split you were wanting to get.

Find a new HVAC guy.