ASHP for two buildings

Jeff Mowatt · 08-21-12, 03:24 AM

Greetings all,

After joining I note that everyone else is in another country, but I guess the principles are the same.

I'm interested in installing an air to water heat pump that will replace an oil fired boiler and service two buildings. A two bedroom stone cottage and smaller detached barn..

I don't intend to do it myself but would like to know if what I'm thinking is viable.

I was inspired by someone who's installed this kind of system[/URL] in a nearby village in the Forest of Dean, UK

I'm thinking of installing on a south facing wall between the two buildings which are about 50 feet apart.

Insulation improvements are under way

Xringer · 08-21-12, 09:06 AM

Welcome Jeff, we do have posters from all over. They have many different levels of expertise.
You might find some good assistance here.

Please provide some details about the system in the nearby village that inspired you.

I'm using a couple of ASHP units (ductless mini-splits) to replace our oil burner (oil is now the back-up system),
but mine are air-to-air heat pumps. (although I do have a small hotwater ASHP now).

My forced hotwater baseboard units are now lying dormant. Saving us a bunch of money on oil.

Jeff Mowatt · 08-21-12, 09:25 AM

Hi Xringer.

I'm not permitted to post links as a new member. This is the installation. I spoke to the supplier today who are Earth Save Products (esavep.com) and they thought the distance and cost of piping would be a disincentive.

Jeff Mowatt · 08-21-12, 09:26 AM

The site again:

forestecoopenhomes.org.uk/cherrytreecottage

Piwoslaw · 08-21-12, 10:14 AM

Welcome to ER, Jeff

Yes, it is technically possible for an air-water heat pump to service two buildings, though with 50ft you'll have noticible losses. I can imagine a setup more or less like this: Heat pump on one building, heat storage (buffer) inside that building, plumbing from the buffer to both buildings. The hp and storage are in the building which requires more heat, or more often.

Depending on how those buildings will be used (is the cottage used year round, or only seasonally/weekends, how much heat does the barn require and how often, etc.) it may be more efficient (though slightly more expensive) to install two separate, smaller heat pumps, one for each building. How are they being heated at the moment? Are both buildings run off of one oil boiler?

Xringer · 08-21-12, 10:55 AM

Quote:

Originally Posted by Jeff Mowatt

The site again:

forestecoopenhomes.org.uk/cherrytreecottage

That kinda looks like a regular mini-split. Even has a standard ductless indoor air handler.

But, it's been modified, so it can also heat water.. A normal install looks like this.

The advantage of heating water is being able to have multiple zones,
that can be turned on and off..
Whereas the standard ductless indoor unit is basically a single zone.
But it's going to use a less power and be more reliable than other systems.
(Less moving parts, and no running water).

The cost of installation will be less also. Perhaps a pair of inverter mini-splits would work for you.?.

Mini-splits also come with zones.. If you have the money.

Jeff Mowatt · 08-21-12, 12:04 PM

Thanks guys,

The cottage is in full time use as my home and I work from home. The barn is let for holidays, typically summer but some winter use due to local nature interests. It has solar water heating which works well and a log burner.

I had in mind an ASHP to water unit, mounted mid way on a large south facing stone wall which runs alongside both buildings such that the ASHP and a buffer store would sit about 25ft from each. I would build a store for the buffer tank.

Alternately if I install two units, I could place both within about 15 feet of the respective building. However, I'm now leaning toward a single installation just for the cottage leaving the barn asis.

Xringer · 08-23-12, 09:58 AM

I saw this picture on the web. It seems to be an ASHP hotwater heater.

I wondered why it would have a hot-cold change over valve.?.
But, then it hit me. It's used for defrost mode.
(Just like my Sanyo units uses cooling mode in the winter to melt ice on the outdoor coil)..

ThomSjay · 10-06-12, 01:53 AM

Quote:

Originally Posted by Jeff Mowatt

A two bedroom stone cottage and smaller detached barn..

I'm thinking of installing on a south facing wall between the two buildings which are about 50 feet apart.

Is it possible to build a "green house" on the house or the wall? This would allow greater heat build-up for the ASHP.

08-21-12, 03:24 AM	#1
Jeff Mowatt Lurking Renovator Join Date: Aug 2012 Location: Forest of Dean Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	ASHP for two buildings Greetings all, After joining I note that everyone else is in another country, but I guess the principles are the same. I'm interested in installing an air to water heat pump that will replace an oil fired boiler and service two buildings. A two bedroom stone cottage and smaller detached barn.. I don't intend to do it myself but would like to know if what I'm thinking is viable. I was inspired by someone who's installed this kind of system[/URL] in a nearby village in the Forest of Dean, UK I'm thinking of installing on a south facing wall between the two buildings which are about 50 feet apart. Insulation improvements are under way

08-21-12, 09:06 AM	#2
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Welcome Jeff, we do have posters from all over. They have many different levels of expertise. You might find some good assistance here. Please provide some details about the system in the nearby village that inspired you. I'm using a couple of ASHP units (ductless mini-splits) to replace our oil burner (oil is now the back-up system), but mine are air-to-air heat pumps. (although I do have a small hotwater ASHP now). My forced hotwater baseboard units are now lying dormant. Saving us a bunch of money on oil. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

08-21-12, 09:26 AM	#4
Jeff Mowatt Lurking Renovator Join Date: Aug 2012 Location: Forest of Dean Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	The site again: forestecoopenhomes.org.uk/cherrytreecottage Last edited by Piwoslaw; 08-21-12 at 09:58 AM.. Reason: Added link

08-21-12, 10:14 AM	#5
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Welcome to ER, Jeff Yes, it is technically possible for an air-water heat pump to service two buildings, though with 50ft you'll have noticible losses. I can imagine a setup more or less like this: Heat pump on one building, heat storage (buffer) inside that building, plumbing from the buffer to both buildings. The hp and storage are in the building which requires more heat, or more often. Depending on how those buildings will be used (is the cottage used year round, or only seasonally/weekends, how much heat does the barn require and how often, etc.) it may be more efficient (though slightly more expensive) to install two separate, smaller heat pumps, one for each building. How are they being heated at the moment? Are both buildings run off of one oil boiler? __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.

08-23-12, 09:58 AM	#8
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I saw this picture on the web. It seems to be an ASHP hotwater heater. I wondered why it would have a hot-cold change over valve.?. But, then it hit me. It's used for defrost mode. (Just like my Sanyo units uses cooling mode in the winter to melt ice on the outdoor coil).. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

08-21-12, 09:25 AM	#3
Jeff Mowatt Lurking Renovator Join Date: Aug 2012 Location: Forest of Dean Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	Hi Xringer. I'm not permitted to post links as a new member. This is the installation. I spoke to the supplier today who are Earth Save Products (esavep.com) and they thought the distance and cost of piping would be a disincentive.

08-21-12, 12:04 PM	#7
Jeff Mowatt Lurking Renovator Join Date: Aug 2012 Location: Forest of Dean Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks guys, The cottage is in full time use as my home and I work from home. The barn is let for holidays, typically summer but some winter use due to local nature interests. It has solar water heating which works well and a log burner. I had in mind an ASHP to water unit, mounted mid way on a large south facing stone wall which runs alongside both buildings such that the ASHP and a buffer store would sit about 25ft from each. I would build a store for the buffer tank. Alternately if I install two units, I could place both within about 15 feet of the respective building. However, I'm now leaning toward a single installation just for the cottage leaving the barn asis.