Who has a heat pump?

[miss_chance]

Totient and I are looking to replace our quarter-century old oil furnace with a modern system. The buzz-words for the thing we're thinking of getting include:

Mini-split (small units in each room, connecting to a single heating unit outside),
Multi-zone (separate controls for each unit),
Ceiling Cassette (vs wall-based), and
"Hyper Heat" or something

Comments

[earthling177]

I don't have one but know a bunch of people who do in Brazil, where such systems are common. Thing is, it doesn't get that cold in Brazil. One thing I'll warn you about, is that mini-split systems vary by a lot, the most common ones have outside units that are just as loud as any central A/C would be. And a lot of heat pump systems, mini-split or not, annoy a least some people because they have a defrost cycle that switches the system to A/C mode every once in a while to remove the ice from the outside unit -- some of them turn on the electric resistance backup heat during that period, which increases the cost, some of them don't and pump cold air into the rooms during the defrost cycle. Just one of the things to ask about while shopping.

All that being said, one of my neighbors here in Woburn recently installed a Mitsubishi mini-split system (towards the end of summer, in fact) and they seem to be pleased by the performance. I haven't talked to them about it after winter started, I'd be curious to know how it performed during the couple of evenings we had -10F around here and how much it's costing in electric, but I can tell you that the inside units I've seen (they have I think 5 inside units and 2 outside units, and I have not seen the ones in the more private areas) are mounted high up in the walls and are very quiet. To this day I have not heard their outside units from the 20 feet or so away, and my central A/C unit makes enough noise to be heard way further than that, so I'd say the units are *much* quieter than usual and I'd consider installing them based on that alone. I also know that my neighbors originally had a hot-water radiator system that is still in use, but I'm not sure if they are using it just as backup for very cold days or if they turn off the heat pump during serious winter.

I can definitely put you in contact with them if you want to ask more questions, or I can ask them and pass the answers your way.

Another thing to consider, in case your present system is even remotely satisfactory, is to install a new furnace (either gas or oil) and a heat pump instead of central A/C -- I know people who do that, so the thermostat can choose the cheapest mode on the fly: for mild days the system runs the heat pump, for serious cold or defrost mode it runs the gas/oil furnace and the electric resistance backup (which tends to be expensive to run) only comes on if the furnace fails to work. The biggest problem in that case is losing the multi-zone, the next problem is that A/C is less efficient when the registers are low (floor or wall, instead of ceiling) because the system was designed primarily for heating (but my home has such registers and the A/C works fine if not the most efficient ever).

In any case, I am under the impression that the key to silent or very quiet systems is to ask for "Inverter" or "multi-speed" for both the compressor (outside unit) and the evaporator (inside unit), which is where the Mitsubishi (and, I'm told, Panasonic) units excel.

Good luck!