Name Brand Air to Water Heat Pumps getting closer to US

[peakbagger]

I see Mitsubishi is selling air to water heat pumps in England. https://les.mitsubishielectric.co.u...ultra-quiet-puz-monobloc-air-source-heat-pump

They are "monoblock" units where all the refrigerant is outdoors. Taco is offering a monoblock made in Europe combined with indoor Taco unit.https://www.tacocomfort.com/documents/FileLibrary/System-M_Homeowner_Catalog.pdf

There are few Canadian firms selling them but definitely not name brand.

There is lot of hate for heat pumps in England these days. There are many very old homes that are marginally insulated with big heating loads that are being forced to switch to electric heating. Heat pumps are best used in modern energy efficient homes with low heat loads so the heat pumps are getting blamed.

 

[EbS-P]

I just paid $450 for a hvac load calculation. An accurate load calc must be done when changing out equipment. Mine comes out that I’m 1 ton undersized. Don’t guess. Just do the load calc. Choose a 99.6% heating design temp and a 0.4% cooling design temp.

https://www.captiveaire.com/catalogcontent/fans/sup_mpu/doc/winter_summer_design_temps_us.pdf

If going air to water plan on electric backup in the storage tank. Or a woodstove.

 

[begreen]

There is lot of hate for heat pumps in England these days. There are many very old homes that are marginally insulated with big heating loads that are being forced to switch to electric heating. Heat pumps are best used in modern energy efficient homes with low heat loads so the heat pumps are getting blamed.

I was nervous because of that kind of talk about heat pumps back in 2006 when I put ours in. There were a lot of negative comments but when traveling in Asia I saw that they were common, so I got the best available. It works well for our climate in spite of our old house with too many large window areas. Our climate is similar to England's but I suspect our power is cheaper.

 

[stoveliker]

It's amazing how many mini splits one sees in e.g south Korea.

And I can tell you that city folk there do like there comfort.

 

[KDubU]

Mini-splits work well in many climates, it’s the home and homeowners lack of understanding that is the issue. We had two in our other home in Maine and they kept the propane boiler from firing up most of the time. Size them right, purchase a good unit and get them professionally installed by a reputable company.

 

[EbS-P]

I see the real advantage with air to water is domestic hot water and heat in one system. Not sure what the cost comparison is VS HPWH but with 80 gallon units running $2600+ it probably works out for larger homes/hot water demand.

 

[peakbagger]

Dont forget cooling in the equation. Instead of duct work, cold water is pumped around the house to local terminal units (that can look like minisplit heads). Far more efficient. As long as people up north realize that there needs to be backup for very cold periods its a hard to beat system.

 

[SpaceBus]

The monoblocks sound like an interesting concept. Since all the refrigerant is outside in the unit, these should be fairly easy to DIY install.

 

[woodgeek]

The key issue (IMHO) is what kind of COPs can be achieved at the water temps needed for low temp hydronic radiation, or for conventional high temp radiation, relative to the COP achieved in conventional air to air HPs.

The UK and New England are big on hydronic heating. The rest of the US much less so. I switched from hydronic to retrofit air ducting in 2010, and am still ripping out the abandoned hydronics room by room a decade later.

I still think air to water to hydronic radiation is a bit of a half measure if you are going to want central cooling later.

That said, I would love to have a monoblock outdoor unit that circulates water (or glycol) to my indoor unit, rather than refrigerant. This will be MORE important in the future when the refrigerant is a flammable gas like propane or cyclopentane.

 

[begreen]

It's amazing how many mini splits one sees in e.g south Korea.

And I can tell you that city folk there do like there comfort.

They are all through Asia. We saw them in India back in 2004 and in Hawaii in 2000.

 

[NoGoodAtScreenNames]

I see the real advantage with air to water is domestic hot water and heat in one system. Not sure what the cost comparison is VS HPWH but with 80 gallon units running $2600+ it probably works out for larger homes/hot water demand.

Interesting idea of combing both into one. I’d be a little worried about my potable water traveling around through the house’s heating system - but that’s probably just a reflex to having boiler with green copper pipes all over my basement.

 

[begreen]

Interesting idea of combing both into one. I’d be a little worried about my potable water traveling around through the house’s heating system - but that’s probably just a reflex to having boiler with green copper pipes all over my basement.

It would be a separate sealed water system, likely with a glycol solution.

 

[peakbagger]

Search for John Seigenthaler articles, he has many of them regarding an integrated heating, cooling and domestic hot water loop.