I think these links are the information you might be looking for and a good place to start.

Nordic Air-To-Air Heat Pumps

Nordic Air-To-Air Heat Pumps - Brochure

Nordic Air-To-Air Heat Pumps - Technical Manual

IMPO

SR

I'm not sure what's up with the Nordic Air recommendation above but if you're in the US, this Canadian manufacturer is a relatively small company and is not particularly well known here.

A better choice would be a US brand (irrespective of where made) because you'd experience better parts availability, distributor attention, and HVAC contractor familiarity. Pick the contractor as the primary choice and let the ones you speak to recommend the equipment they know that will provide the functionality you need.

You should research inverter type heat pump. Carrier and Bosch are two manufacturers who offer this type of heat pump. I second Elmer's advice of looking into brands that are common for your area. You should have several choices in your part of NJ.

Heat pumps can produce heat down to very low temperatures. The question becomes what is the heat loss of your house at these temperatures. The back up resistance heat is needed to make up any difference between heat gain and loss. Heat pumps should be sized for the cooling load and not the heating load. You can't over the size the heat pump in an attempt to reduce the backup heating frequency.

I assume natural gas is not an option. Gas is currently the cheapest fuel to heat a home in NJ.

I had looked for companies in my area. Some had bad reviews. The equipment they work with generally wasn't what I was looking for. I did look into a couple brands that were supposed to be good. I was able to find a couple dealers that service my area but are a ways away. Even then, I was hoping for input on best brands/models that actually do well with the temperature range without needing a second fuel assist. Then see what dealers the manufacturer lists near me.

I have no faith in contractors. Would not trust what they recommend. Vendors in my area in my experience don't know jack about what they are doing. Seems to be too much work and they rush from one thing to the next and don't care much about bad reviews or doing bad jobs because there is already too much work and it won't slow them down. Doesn't seem like hardly any know what a proper heat load calculation even would be.

I am doing a full heat load HVAC calculation using Wrightsoft for Manual J, D, and S. It will determine the size by heating or cooling side depending on which load is greater.

There are other factors like not needing as large a flue pipe if I don't have gas backup. But that is a long explanation.

I did a deeper dive into energy costs between gas and electric in NJ. Even though electric heat pumps are much more efficient than gas. Gas still turns out to be less than half the price per BTU. Looks like I might end up doing a condensing gas HVAC system as long as the association doesn't give me crap about adding another vent in the roof.

Re: Stymie

“I am hoping people can recommend air sourced cold climate heat pump, centrally ducted. Brand, model, or series that don't need gas or electrical assistance when temps get down to the single digits Fahrenheit or have problems cooling in the mid to upper 90s.”

The only HP’s that meet that criteria are geothermal. All other heat pumps still have Defrost Cycles that must either use some form of fossil fuel or electric resistance heating elements during this mode. The only HP’s that don’t have Defrost Modes are geothermal - but even geothermal must have a secondary stage of backup resistance heating elements for times when the envelope is loosing more heat than the HP can produce and in case of ‘Compressor Lockout’ for ‘Emergency’ backup mode.

There is almost no escaping this. The only way to possibly escape this when employing HP’s is to employ multiple HP’s in cascade mode so other HP’s that are ‘Staged’ can come on line during the primary HP’s defrost cycle or when the heat loss is too great for the primary unit.

I would not advise such an installation unless you had a very specific application in mind. If that were the case you would be better off hiring a commercial HVAC professional engineering company, as this is way beyond the scope of most in the residential market.

WaterFurnace Series 7

IMPO

SR

I knew it wouldn't be long before our "everyone should spend $75K (or more sometimes) for a ground source heat pump system" advocate to speak up.

Stymie, you need to find a competent HVAC contractor, there's no reasonable substitute. I'd suggest that online ratings and comments are not the best source and can be more misinformation than real information since often it's only people who want to grouse and get even have much to say. Ask friends in the area. Ask neighbors. When you call bidders, ask for local references.

What kind of fuel source does your home use right now for heating? If you have the connections and tanks in place for oil or propane, is there a reason to not use that for a backup source?

Ground source heat pumps are usually the most expensive approach. They do work. If your budget is unlimited and your home has enough of the right kind of space, that's another way to go.

Glad to hear you are doing your own load calculations using Wrightsoft. I would be interested in seeing the results. For NJ I would expect the heating load to be about twice that of the cooling load, but every house is different.

My results would not apply well to others with the Wrightsoft software. I live in a 2 floor corner unit condo with neighbors behind, below, and on 1 side of me. Which leaves me with SW and SE exposures and the attic above. Plus the builders (Hovnanian) are incompetent shysters so my place is beyond inefficient to start with. I have to guess as to what things like wall insulation will be when I get them insulated. Currently, the heat load is actually about twice the cooling load for preliminary calculation. 32.5K btu heating vs 15k btu cooling. Current HVAC has 88K BTU and can't keep up as we get down toward single digits and 3 ton cooling which struggles to keep up over 90 degrees. Which gives you an idea how bad Hovnanian is.

Yes, online ratings and comments are not that reliable. But going onto contractors websites and seeing what brands they work with and looking into those I found weren't what I was looking for. I'd expect even the best contractors to have some bad reviews. Not everyone will be happy and not everyone even understands what they are posting about. But some just had tons of bad reviews and BBB ratings. My HVAC guy I use for maintenance is decent. But he impresses me as more an old school guy and not up on current technologies and comparing them.

Geothermal is not an option. I live in a condo on a reclamation site. There is no space for it, wouldn't get approved by the board, and as a reclamation site they frown upon piercing the barrier of material that wasn't hauled away with the initial cleanup.

I did use http://www.warmair.com/html/fuel_cost_comparisons.php to do a cost comparison of natural gas (current) vs HP electrical. Each way I tried it, electricity was at least double the cost based on values in a few of my bills. I will try other sites to confirm it. But it looks like although HP is more efficient, I would end up paying double due to natural gas and electric prices. Condensing furnace is looking at a better option at this point. And can route that vent through different chase to attic.

Flue pipe issue is that incompetent builders put downstairs neighbors MUA vents, our shared flue pipe, and my return air in the same chase. Flue is in wrong location and probably MUA vents which leaves not enough space for my return air. If I can have a smaller flue by eliminating part or all of my use of it, more space for my return air ducts.

Are you interested replacing your gas furnace with a heat pump primarily to eliminate your flue pipe? If that is the case then you are allowed to install a PVC exhaust and intake out the side of the house you could install a 90%+ efficiency furnace. If that is not allowed, then you could go straight up with a 3 inch PVC pipe to the roof. You would still need a flue for the gas hot water heater unless you replaced it either with an electric hot water heater, which I don't recommend, or were allowed to install with a power vent to the exterior.

What is the size of the condo. Your initial calculations seem low. If the condo was built in the 80s you should use R11 for wall insulation. If you can go in the attic you should be able to measure the insulation. The fact that your furnace and AC can't keep up is probably due to poor duct work and how the equipment is operating. However I do agree Hovnanian has been notorious for poorly built condos and townhouses.

"Condensing furnace is looking at a better option at this point. And can route that vent through different chase to attic."

I think it needs to go to the outside, not just to an attic. Most HOAs won't approve new wall or roof protuberances.

As I said in another thread, choose an HVAC contractor, not an equipment brand. Unless you have specific requirements for a type only available from or produced in a superior way from one brand and not from others. And if that's the case, get contractor names from the manufacturer, most have that information and also which ones have attained higher levels of accomplishment either through unit volume, ongoing participation in training, or both.

"Geothermal is not an option. I live in a condo on a reclamation site."

Hahaha. Not laughing at OP but at the recurring geothermal for everyone recommendation.

Interesting -

I went to the NEEP site the OP linked to and played around with the various numbers. I initially selected 80000 BTU/hr at 5 degrees and there were none. I reduced that number until I got some hits, and that number was 57000. All the hits were Mitsubishi or Trane/Mitsubishi. If I lowered my requirement to 50000, then a few more showed up, including LG and Gree, but most were still Mitsubishi. I don't know what I really need; my primary purpose is to add some AC (I have none) and reduce the operational cost of my 68200BTU/hr resistance-heated boiler.

Have you checked out geothermal heating

Are you replying to me, Patricia? Yes, initial cost too high. Did get solar panels, however.

Re: Stymie 'OP'

“I am hoping people can recommend air sourced cold climate heat pump, centrally ducted. Brand, model, or series that don't need gas or electrical assistance when temps get down to the single digits Fahrenheit or have problems cooling in the mid to upper 90s.”

“I was hoping for input on best brands/models that actually do well with the temperature range without needing a second fuel assist.”

“Probably a good post for Canadians to chime in on. If I can get a few ideas I can research them and see if they have installers in the area who aren't horrible (like most contractors in north east NJ).”

Elmer J Fudd:

“I knew it wouldn't be long before our "everyone should spend $75K (or more sometimes) for a ground source heat pump system" advocate to speak up.”

“Hahaha. Not laughing at OP but at the recurring geothermal for everyone recommendation.”

Seems to me that the OP is already more knowledgeable than the non-professional posters on this thread.

Can any one of you answer the question of how to install a HP without the need for backup or fossil fuels? That was the original question.

FSQ - ‘Me’

“I would not advise such an installation unless you had a very specific application in mind.”

I am a completely disinterested party. I’m only addressing a technical question. I do not know what stake you think I have in this.

‘Fudd’ - You offer more financial advice - with low technical content.

This website is poorly moderated and has gone way down hill over the years. I do not see many of the really good posters on this site very much anymore. I wonder if it’s because there are too many mean spirited, nasty SOB’s here that they feel, ‘why bother’.

IMPO

SR

The condensing furnace exhaust can't go through the chase with the current flue since the chase needs to be fire rated and plastic exhaust pipes would not qualify. By attic I meant routing through the attic as a roof vent. Can't go out the side wall since that would change the facade which is not allowed and be right over my neighbors windows and front door.

The reason my current system is so bad is because the builder put no insulation in the walls and sealed nothing. There is an inch gap between each floor and my back and side cinder block fire walls which allows direct access for attic air to go down the walls and between floors. Except at the top of my sidewall which is a 2.5 to 3" gap. Not a single bit of ductwork was sealed and nothing was measured right before it was cut by hand. A couple duct take offs in the attic just fell out of the ductwork when I was checking them. Not even a screw to hold it in place. The transition between return plenum and filter box is just leaning against the wall it goes through. Not attached at either end. The HVAC system is pulling tons of air in from the attic and walls and blowing an equal amount out as well. My HVAC design with Wrightsoft is based on where I expect to be when I replace the HVAC and duct, not where I am now. I have sealed everything in the attic, sealed a lot of things in the walls. I am in the process of re-insulating the attic with new insulation to R53. I am looking toward injection foam for the walls as my prefered option. My condo is 2 floors, corner unt, and about 1500Sqr ft. facing southwest. Neighbors on 2 sides and below.

I am looking into efficient and cost effective options. The flue pipe fix is also part of the consideration. I won't know the full specs till I open the wall and get in there. I think I have about 10 inches between the wall and flue pipe at the moment for the return air. And limited room to move stuff and no idea if moving neighbors MUA vents around is an option or not.

The site I used http://www.warmair.com/html/fuel_cost_comparisons.php for the cost comparison figures out the cost per BTU based on the efficiency, type, fuel source of the unit with the costs of that fuel source. I don't know the assumptions or equations it uses. HP is more efficient, but due to the cost of gas and electricity, a gas furnace costs half as much per BTU.

Stymie, is there anything to learn from any of your neighbors who have already confronted the same challenges you're trying to deal with now?

"Can any one of you answer the question of how to install a HP without the need for backup or fossil fuels?"

Most electricity in the US is produced using fossil fuels. Even with the important move away from coal and at least, for now, to natural gas, a fact people like those in the ground source heat pump business like to ignore is that more energy (ie, more efficiency) is extracted from natural gas in a residential furnace, for instance, than from burning natural gas at a power plant.

If there were a mass movement to air source heat pumps from gas or oil furnaces, the resulting incremental electricity demand could only be supplied (in most places) by more use of natural gas power plants. Which overall would use more gas than if the gas were burned in homes.

The gardenweb forums are mostly visited by ordinary people, sharing whatever knowledge they have with others. There are other sites like hvac forum to hear from pros in the business. The most knowledgeable pros of all kinds usually offer more than one answer to questions but your contributions seem to be the same every time. The most expensive HVAC approach - appropriate in limited circumstances, yes. Limited is the key word. Most people have limited budgets and shooting for the sky, price wise, is often not what they're interested in learning about.

I'm sorry you feel the need to insult participants here by calling them mean spirited, I think people try to help and address questions that are posed as they best can.

Seems like the OP’s initial question was “hoping people can recommend air sourced cold climate heat pump, centrally ducted. Brand, model, or series that don't need gas or electrical assistance when temps get down to the single digits Fahrenheit.........”

It looked to me that the responses and information links indicated that any HP, other than geothermal, would require a supplemental heat source at the lower temps. It didn’t seem to me that @fsq4cw was trying to sell a system.

Not trying to argue with anyone here.

I suspect the easiest approach will be to more or less "replace" in kind what's there now.

"Stymie, is there anything to learn from any of your neighbors who have already confronted the same challenges you're trying to deal with now?"

For most people, they are hearing the extent of the issues from me for the first time in our facebook group. Many acknowledge that there are issues with getting enough heat/cooling to parts of their condos. And some already know they didn't insulate the walls. But no one else has really done what I am doing in trying to fix the problem in full. 1 person in section 2 (under different management and board" ) had put in a high efficiency York system that vents through the roof. But I think they just matched the specs on his existing system and didn't fix the other issues. Many people are renters and don't have the option of doing something. Someone had stated they had seen a company that does injection foam insulation in the complex before but no members of the forum have posted first hand experience. I've asked.

Plus to see the gap between me and the side neighbor I had to open the drywall wall between us and am guessing I am only the first to have done it. Was able to look between my floors when moving a bathroom fan out of the way as well as lifting the downstairs return air intake enough to see. Plus I used a bore scope to look into a bunch of places. Had to take off the bottom cover of my furnace, pull out the filter, lay on the floor and stick me head in to see the return air duct just leaning against the wall. Pulled up all my attic insulation to see the horrible job they did. Most people have not seen any of those things.

Most people have condos with only 1 or 2 sides exposure to the outside. Bottom condos have the front, top condos have front and attic. They are a little drafty and unevenly heated but for the most part the heating/cooling costs aren't wallet breaking so they just deal with it.

What I have now is a standard gas 80% efficient unit that is way oversized if the place was insulated and sealed. I will be doing a 100% duct replacement myself. As well as sealing it. For obvious reasons I will have a contractor do the HVAC install. And will probably be a pain in their ass to be sure it is done right.

Current Heat load calculation is 38,161 BTUs. Cooling 13,243, cooling latent 3302. Might change a little as I design the duct layout more and get equipment selected..

@fsq4cw

"Can any one of you answer the question of how to install a HP without the need for backup or fossil fuels?"

I've seen it stated that many heat pumps reverse the coolant flow to heat the outdoor coil to defrost it. Sometimes an electric heating element will counter the cold air that results indoors from it. Maybe others might have an outdoor external electric heating element for defrosting? Aside from that, some HPs maintain enough heating capacity at single digit temps to heat a home without going out of bounds from ACCA capacity ranges for an HVAC design. I couldn't tell you exactly which brands have what capabilities off hand. I have seen some Canadians state their HPs didn't need assistance in some of the lower temp ranges. I have been looking into these things on and off for a few months so can't say exactly where I read different things.

Geothermal and water sourced heat pumps would be a good alternative for air sourced, but living in a condo on a reclamation/landfill site negates that as an option for me.

"Can any one of you answer the question of how to install a HP without the need for backup or fossil fuels?”

Yes, I can but first, before long explanations, can you tell me about the size of your mechanical room and what’s in it? Your 2-floor condo, is it 1500sq. ft per floor or total? How far is your mechanical room from what I imagine would be a roof top HP installation and approximately how many feet in height between roof top and mechanical room (this might not be an important spec but of interest none-the-less)?

SR

This is the simple answer

Some heat pumps are designed operate independently without back up heating, while others are designed to use a back up heating system. Whether or not you need a backup heat source for your heat pump will depend on the type of heat pump you purchase, your climate zone, and the design and efficiency of your home.

My home is 1500 sqr ft. total. HVAC, hot water tank, washer and dryer are all in my utility closet. Feet between mechanical room ceiling and roof top is approx. 27ft. I have 1 side of a sloped roof above me which piques at 21 feet at the wall between me and my back neighbor. I am also planning on fixing my MUA vents for combustion air for my dryer, HVAC and hot water heater. Right now I rely on all the holes the builders left in the room to get enough combustion air for them. Will need the HVAC design to determine size of MUA vents. Then I can fix those and seal the holes in there.

I am on the border of climate zones 4 and 5 on the east coast near NYC. Figure a heat pump that could handle not having a backup for Canada or at least colder zones would be fine for where I am. But after doing cost calculations for electric heat pump vs. gas HVAC based on utility prices per BTU in my area, it looks like a high efficiency condensing HVAC system would cost a lot less in utility costs.

I've read so many threads on this subject, so I have forgotten your situation. Why do you want a heat pump without any backup?

Re: Symie

“Can any one of you answer the question of how to install a HP without the need for backup or fossil fuels? That was the original question.”

I see you’ve already made your choice, that’s great. As you have already chosen a gas system, I’ll try to give you the short answer.

An Air-Source Air-to-Liquid HP utilizing Variable Speed Compressor technology (VRF) & Enhanced Vapour Injection (EVI), that you already indicated that you know something about, is the choice of HP able to operate at very low Outdoor Temperatures averaging a ‘Seasonal’ COP fairly close to that of geothermal - without the need of a ground loop (geothermal is still the Gold Standard - but at a price).

The indoor distribution is via hot or chilled water feeding in-floor radiant, heat emitters (radiators) fan coils units to change indoor temperatures quickly (heating or cooling), hydronically fed central fan coil units (to condition an entire floor), chilled beams or any combination there of.

The way the Defrost Mode can work without backup is that in heating mode, the only mode requiring Defrost, is that a hydronic system employs the use of a buffer tank that stores hot water. The buffer tank can have many functions besides the prevention of short cycling (as when one small zone such as a bathroom in-floor radiant zone or even just a hydronically heated towel warming rack calls for heat), depending on design of the system. It can be configured that during Defrost Mode, the thermal energy stored in the Hot Water Buffer Tank is diverted and used to defrost the HP condenser coil while simultaneously continuing to heat the home, as there is enough stored thermal energy to do both. Depending on the design of the buffer tank system there might be as much as a 5˚F -10˚F drop in temperature of the stored hot water - but that temporary drop in water temperature would hardly be felt in the home because unlike a ‘Conventional’ Air-Source HP that completely switches over to Air-Conditioning, the Hydronic system might see that drop in buffer tank stored water from possibly 120˚F to say, 110˚F - not enough to feel any real difference in the home for perhaps the 20-minutes it takes to defrost and even less so with a system designed with all emitters operating at a design water temperature of 110˚F. Afterwards, the buffer tank quickly recovers when the HP fully switches back to heating.

Keep in mind that when doing things the ‘Conventional’ way you still have at least 2-separate systems, such as a gas furnace and an air-conditioner. The system described above can be 1-fully integrated system for space heating, air-conditioning, Domestic Hot Water production - all with 1-source of energy, 1-utility entrance and 1-bill. It can also be designed to perform all functions all at the same time.

“Current HVAC has 88K BTU and can't keep up as we get down toward single digits and 3 ton cooling which struggles to keep up over 90 degrees.“

Given your situation, I personally would be looking to do something quite different. While you should be able to sort out your HVAC challenges with conventional forced air technology, I would be concerned that some issues while ameliorated were not quite resolved leaving me unhappy.

I might therefore choose water knowing that if I could deliver the right temperature water to all distribution points within the envelope, an easy task with proper design, that I could with the right emitters and fan coils, control the temperature in all parts of the home - heating and air-conditioning.

Keeping to a specific temperature, water is easier to control than airflow. A modern water ECM circulator (pump) might drawing 50-watts (small incandescent light bulb) for the whole house instead of a ½-HP Blower Motor. Hydronics are much easier to zone and control than forced air. A 1-inch insulated pipe might be easier to install than duct work.

"A given volume of water can absorb almost 3500 times a much heat as the same volume of air, when both undergo the same temperature change.”

3/4"tube = 20"x12" duct

3/4"tube = 18" ø duct

Having said all this, I would still insist on an electric boiler backup in case of a real Emergency, such as a Compressor Lockout Condition or if for any reason the HP could not keep up with the envelope or DHW heat loss, if that were part of the design - but not for reasons of Defrost!

While I’m not on-site to first hand evaluate your situation, if this were my home, I would look to do something cutting edge and radially different, rather than ducted forced air that has given you no real satisfaction.

Please keep in mind - I am NOT trying to sell you anything.

A HP Hydronic conversion would be a much more expensive Premium solution!

‘Think Water’ (But don't drown in the details)

IMPO

SR

"I am NOT trying to sell you anything.

A HP Hydronic conversion would be a much more expensive Premium solution!

‘Think Water’"

In YOUR experience, how common are air to water heat pumps in the metro NY area?

How often do you see people install water lines for radiant heating when walls are closed and underfloor access is not available for one entire floor?

fsq4cw

I was previously looking into a combined hot water tank/HVAC solution. But with the buffer water tank, I ruled it out due to space constraints in my utility closet. My concerns with hydronic heat is that I don't want to remove my downstairs floor at this time. Someday I want to convert from carpet to hardwood. But not any time soon. Carpet would insulate the heating too much. Plus, I don't like the idea of having to pull up the floor if there is an issue. It also puts my downstairs neighbor at risk since any leak I have had always made it to them and had to fix the damage. Plus, for us to put in hardwood flooring, we are also rightfully required to put in soundproofing so the downstairs neighbor doesn't hear every footstep and what not which is not compatible with the hydronic heating.

When I am finished sealing and insulating my condo, the heat load ACCA manual J, D, S design that I am working on shows a much reduced load. Heat load calculation is 38,161 BTUs. Cooling 13,243, cooling latent 3302. I am doing the design based on how my home will be and not where it is at right now.

Right now nothing in my ductwork is sealed and nothing was ever measured right. Nothing in my home was sealed eighter. I went into more detail in an earlier post but to simply but it, the builders were negligent.

I've compared the utility costs for my area between heat pumps and gas furnaces. The reason I changed my mind for gas is that every calculation I did on every website based on local gas and electric costs has come out with gas being about half the cost per BTU. I guess gas is just cheap in NJ. Even comparing a high efficiency HP vs a standard 80% furnace it was about 45% cheaper per BTU output.

mtvhike

If you hit ctrl+f and search for "flue" you will find all the parts of conversations on it.