Any experiences with heat pumps for heating & hot water?
Renovation question: does anyone have experience with installing and using a heat pump system (Daikin Altherma, Mitsubishi Hyperheat, etc) for heating and producing hot water? Many houses have ductless splits w heat pumps for A/C (cooling), but now manufacturers are claiming they have solved the more crucial efficient heating / hot water issue (you can live with out A/C in the summer, but you need heating the winter). Questions: – What are the running costs in the winter? – What brands / systems did you use? So far I seemed to have found the most information about Daikin Altherma and Mitsubishi Hyperheat. – Do you have any backup heating system (fireplace or traditional steam or hydronic)? – What are the installation costs? – If you have any contractor, mechanical engineer recommendations, please let me knwow. Thank you! Bence
beneec
in Heating and Cooling 9 years and 6 months ago
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13 replies
Augustiner | 9 years and 5 months ago
correction: average is $500 in winter and $400 in summer on 4000 sqf 3 family on the common meter with green Mountain (2 ct per kwh more). That includes hot water (electric heat pump). Moderate heating/ cooling.
Augustiner | 9 years and 5 months ago
@Mr. Positive: yes more than enough heat for the whole house! But if you don’t keep it on the cool side it’ll cost you big time! Average bill in winter is $600/month on 4000 sqf. I guess if windows and insulation was worse that would be double
cmu | 9 years and 5 months ago
A search would show you that split-system heatpumps are being installed in very cold climates, Maine, Canada, Vermont (which has an incentive program.) The caveat is that these are more expensive units (as steam-man notes), not the typical ones installed here, and may not support multiple heads (indoor units.) But they work down to -5deg F, at which temp. they are about as efficient as oil burners. So the main problem for brownstones is that you usually need 2 units/floor. In an open plan floor, one unit may be ok. And, of course capacity. My 3000sq ft leaky brownstone needs 90-100kbtu of actual heat (I have a 150kbtu steam boiler.) Most minisplits are smaller. You’d need to insulate very well and stop air leaks to use one effectively.
Master Plvmber | 9 years and 6 months ago
If steam_man says they work well, then maybe, as he suggests, mine were just ill-suited to the space. I’m not alone in having had a not-ideal experience with them, but I do believe that technology is bound to catch up, or has caught up, with them.
steam_man | 9 years and 6 months ago
You guys are killing me with these blanket statements like eman’s comment which I disagree with. We have installed Mitsubishi Hyperheat H2i and plain old City Multi and we have not heard a customer complain about comfort in winter or summer. Some givens which stand whether you have heat pumps or fossil fuel boilers, insulation is important. BTUs don’t care what produces them, gas, oil, electricity or methane emmissions from a cow’s ass. If you are sending them out the uninsulated window frames then you are wasting money. My customers don’t want their money wasted even if less of it is wasted because they installed a gas boiler than a heat pump. Maybe e-man’s respondants are more well heeled. I don’t know… Another given, is sizing. MasterP I’d be willing to bet your system was undersized and not up to par with today’s technology. Was the system sized for heating load or cooling load? My guess it was sized for cooling and undersized at that. Of course it all comes down to costs. Heat pumps are not cheap to install, that is for sure. The most worry free units which are produced by Mitsubishi are going to cost more than a Friedrich, Amana or similar Chinese made unit but the value is there. That is the reason I feel comfortable offering only Mitsubishi. There are lots of important factors to consider here so it is worthwhile to call a reputable mechanical contractor who will be willing to spend some time on the phone educating you on your options. Feel free to give us a call. We are a proud advertiser here on Brownstoner and I myself a long time member of the Brownstoner community. Look us up under Molten Mechanical Metal Works.
Master Plvmber | 9 years and 6 months ago
I really don’t remember the model. We found it here: http://www.mitsubishipro.com/en/professional/residential-applications/building-applications/multi-zone The building was 1833 (!) brick and wood construction with blown-in insulation. For cooling they were the cat’s meow.
randolph | 9 years and 6 months ago
which mitsubishi system was it? ducted or ductless interior units? was the house well insulated otherwise? and how did they perform for cooling?
Master Plvmber | 9 years and 6 months ago
It was two years ago and, yes, the contractor convinced our building these would work well and efficiently for heating as well as cooling. Luckily, we never removed the old circulating hot water system and radiators, so we set the old system to automatically turn on when the weather outside dropped below 40°F. Then our building warmed up. We were a 5-unit, 3-story townhouse in Manhattan. Truth be told, we could leave our 2 Mitsubishi units on and our 600-sq.ft. apt would eventually heat up to about 68 on a 20-degree day, but that still felt cold to us. Together these units gave us 45,000 BTUs when the math suggested we only needed less than 20,000 BTUs so it wasn’t a question of system sizing. As soon as we turned on our radiators, we could get to 72°-74°f in a few minutes. Again, our monthly electric bill would go from $40 in the fall to $120 in winter. This was a rent stabilized apartment in which my wife and I would choose our battles. The building has since been razed to make way for luxury condos. Bastards. I tell this story way too much to my customers, but I’m glad I lived it. www.72fLLC.com
randolph | 9 years and 6 months ago
Master Plumber- when was this and what type of equipment? my understanding is that in the past few years the heating capability of the newest mitsubishi units is improved. their spec sheet claims the operating temperature range for heating (with the 60k BTU model) is -4 to 60 °F. http://www.mitsubishipro.com/en/professional/products/heat-pump-systems/city-multi-vrf/city-multi-vrf-heat-pumps—outdoor-units/pumy? this is not to say that it is cost effective, but you say they “didn’t work under 40 degrees”. Mitsubishi claims otherwise, but it could be a false claim. thoughts?
randolph | 9 years and 6 months ago
August- electricity costs aside, does it keep your house warm enough? is your house passive or very well insulated? do you have ducted or ductless units? in term of costs- what would you say is your average monthly electric bill in a normal winter, and how big is your house?
Master Plvmber | 9 years and 6 months ago
What eman said. I lived in a NYC apartment with Mitsubishi units for a couple of years and they didn’t work under 40 degrees. Meanwhile, my monthly winter electric bill was identical to my July bill.
Augustiner | 9 years and 6 months ago
I have a Mitsubishi h2i installed. If you don’t have a passive house or a very tightly insulated home this is always be more expensive than a gas fired heating system. If all winters were like this one Hvac is a reasonable idea, but not if it’s freezing for 3 months. Don’t forget the more efficient heat pumps will cost you more to busy than just a cooling solution. You could save yourself some bucks and invest that into a radiant floor heating system. Because Hvac hearing sucks in terms of comfort in regular size bedrooms. Now if you also want to heat water with the same condenser you’ll need yet another model. One that uses the process heat in summer to heat the water. If you want to be energy efficient and save money on the long run there are solutions that will cost you less money, such as a solar thermal backed gas boiler. Or if you decide to go all electric there are standalone heat pump water heaters. Well – it’s complicated 🙂
eman134 | 9 years and 6 months ago
Stop trying to reinvent the wheel ..Will not work in this climate unless you want a phenomenally high electric bill all winter long…stick with a hydronic system wth a heatpump as a backup. My contact info is in my profile.