Heating options for room addition in MN?

kiwanda

We've recently purchased a 1997 home that includes a "guest suite" the original owners made by converting a third garage bay. It was professionally done and is insulated to code, has good windows, and the floors are dricore over the slab.  Size is approx 12x22 minus partition walls and ceilings are 8'3". Unfortunately it was not connected to the HVAC system; there is a low-end PTAC cut through the bedroom wall and no heat in the 3/4 bath at all.  Winter temps here hit -25 regularly so the PTAC runs a lot, is noisy, looks terrible, and of course is inefficient. We do not use the AC in summers so are looking to replace with a heat-only alternative.



Due to the slab and distance from the mechanical room I'm told we cannot simply connect to existing GFA HVAC, so it will need a separate system.  Here are some of the options I've looked at:



-electric hydronic baseboards



-plumbed hydronic baseboards w/boiler in existing mechanical room



-Steffes off-peak electric thermal storage unit in room



-adding a small GFA furnace to attic space in adjacent garage



-small gas "wood stove" in room



Cost and efficiency are concerns in addition to noise and appearance. We need to keep the space at 50F in winter when unused, 70F when occupied. It also serves as a home office on weekends. A programmable thermostat is essential. 



I'm leaning toward electric hydronic baseboards (possibly with a cove-mounted infrared ceramic unit in the bathroom) due to low cost and ease of install. Any advice on these or other options would be great!



-kiwanda

EricAune

Where @ in MN?

Your research and understanding of the situation is impressive, have you talked with any contractors?  I am about an hour north of the cities, where are you located?  Have you any drawings of the space you could post here? 

kiwanda

Here's a quick sketch

This is basically what the room looks like. To the left is the garage and main house; there's an exterior door behind the bathroom.  It's not an ideal space but is quite useful as a guest room/office...the only real problem is the nasty PTAC which makes it feel like a Motel 6.



We're near St. Cloud, so right in the middle of the state.



-kiwanda

Jack

Simplest

Is a Rinnai ES11C. Gas fired direct vent, programmable.

EricAune

I agree

The Rinnai wall units are great.  Another option, although much more involved, might be to consider panel radiators.