Replies

1. 
   paul_wiedefeld | Mar 09, 2022 01:42pm | #1

   "In my case i keep coming back to a traditional split heat pump with air handler, ducts and damper control."

   That's what you want. Minisplit is a bit of a meaningless term now: It can be a ducted "minisplit" (like Fujitsu or Mitsubishi's high static air handlers) or "traditional" (from the same manufacturers or Trane/Carrier/etc). Very little difference.

2. 
   aunsafe2015 | Mar 10, 2022 07:29am | #2

   "1) I’d like to have a zoned control for every room. Ideally 4 different zones."

   This is going to be very challenging for 110 sq ft rooms. Maybe an expert will have better advice, but if I were you, I'd probably just get a system where you can use something like an Ecobee thermostat with remote sensors, and put a sensor in each room, and either average them or tell the Ecobee which sensor will control the system at different times of day.

   The other possibility is getting something like a zoned 2-ton Trane XV18. But a 110 sq ft room is not going to have the supply duct size to create a "voting" zone. So rather than having 4 zones, you might be able to have two zones. Living space + 1 bedroom on 1 zone, and the other bedrooms on a second zone. Even then, you probably need to oversize the ductwork to get enough capacity for both zones to be "voting" zones.

   The other challenge with this solution is that, although not technically difficult to achieve, it's definitely beyond the scope of what an HVAC contractor is dealing with on a regular basis. So you'd probably get most of them telling you not to do it (largely b/c they simply don't like doing projects out of the ordinary). Or, you might get a poor installation. In other words, with zoning, you need to be extra sure your contractor is very competent. And that's easier said than done.

3. Expert Member
   PETER G ENGLE PE | Mar 10, 2022 11:15am | #3

   With a house that small, there's not much need for separate zones. You won't see any meaningful energy savings by setting back some rooms and heating/cooling the others, and zoning would make the system design far more difficult and expensive (as you are finding out). At that size, a single ducted heat pump or minisplit would more than suffice for the entire house and you might as well just keep all the rooms at the same temperature. Simple, energy efficient, easy to maintain.

1. 
   exeric | Mar 10, 2022 12:19pm | #4

   +1. If a simple plan will work for a particular situation, then that's the way to go.

4. 
   walta100 | Mar 10, 2022 05:56pm | #5

   4 zones in 1025 Sqf seems a bit much.

   Assuming all the walls and windows are of about the same quality your rooms are going to be about the same temp without zoning.

   Zoning can be useful when one room is very different than the rest, like a sun room that is all glass that may need more heat at night and less heat on sunny days or when you have a second story that tends to be a different temp than the main floor.

   If for whatever reason you are convinced you must have zoning I say trying to throttle down a system large enough to whole building, in an attempt to make one zone happy does not seem likely. Most zoning systems have a dump zone where the system sends its excess capacity without regard to what happens to the temp in that room.

   I think having several smaller independent systems is a better solution than one large zoned system.

   Walta