Currently I use a woodstove to heat my place (no ducts). I am thinking about installing an air-to-air ducted heat pump to heat my place. I am trying to figure out what are the important factors (in addition to the cost) I should investigate before approaching a pro.
The winter months here (comox valley, bc. canada) are normally between 0-9 C degrees, but there are days/nights when it dips bellow zero sometimes down to -7C.
Heat efficiency – open crawlspace
My crawlspace has vents (basically holes) to allow for air circulation (to avoid moisture build up) – so it is cold in winter. If I do install a ducted heat pump, the ducts would be in the crawlspace. I was reading that the air coming out of a heat pump is not that hot to start with (25-45 C degrees). So, I was wondering, by the time the heat comes out of the ducts, it may not be warm enough to actually heat the house efficiently. Is this something I should be worried about? Do you have any experience with a similiar situation?
Best Answer
If flex ducting is used it comes pre insulated. If you decide to install a split system make sure it can handle that level of cold. Yes, some can but they are high end units. If you need “emergency heat” or supplemental electric it gets much more expensive to run.
I find when you look at the added cost of installing ducting a “mini split” is a better choice. Mini splits have the outside unit but then run lines inside the home. Each room or zone has its own heat /cooling unit.
Each room or zone can be controlled separately. The cost of ducting can pay for several separate inside units and you wont have the air cooling in the ducts even if insulated.
Mini’s can be cheaper to operate because they are not heating dead air space and if 1 room or zone is not needed to be heated or cooled turn it off and the outside unit slows down drawing less power or cycling for older technology.
What ever you decide make sure your unit can operate to the -7 range, I believe the best one I put in can function to -5 but some can go to -15. They are not as efficient at these extremes in any split system but depending on the brand / model they can do the job. they go into defrost mode more often.