Looking for Large Commercial Air-Source Heat Pump Water Heaters in USA

[nuuvox000]

Hello, the only large, commercial units I have found are the Aegis Lync units that just came out on the market a month ago. Is anyone aware of any other manufacturers that sell large units in the USA? Lochinvar and AO Smith only make ones that max out at about 250,000 BTUh but I'd really like to have closer to 500,000 to 1,000,000 BTUh if possible. Just a little worried about how new the Aegis Lync equipment is. Thanks in advance.

 

[EnergyProfessional]

What is the application? If you heat a room directly, you have a variety of heatpumps or VRF systems. For very large loads you would use a heat recovery chiller or similar.
I don't know where you are located, but i would look at the unusual suspects for chillers/DX equipment.

A large heatpump sounds a bit like an oxymoron. In climates with large heating load, and air source heatpump usually doesn't work well. In climates with suitable low-temps in winter, a 1,000,000 indicates a very very very large space.

They will need to know what the application and conditions are.

 

[nuuvox000]

This is for the domestic hot water for a large apartment complex. The owners are adamant that we use heat-pumps (not water-source though, too expensive) and not electric resistance heating nor gas heating. We are located in Utah and designing to 0 degrees F; we don't recommend air-source heat pumps for everything but like I said, the owners really want it. Let me know if I'm wrong but I don't believe a heat-recovery chiller would help us because the apartment units will be heated by air-source heat pump splits. There's basically not really any extra heat to recover anywhere in the building (again, no gas, no electric resistance heating).

 

[EnergyProfessional]

Probably need backup electric heat. Hot water probably needs to be heated to 120°F. So we talk about a refrigerant lift from maybe -10°F to over 130°F. I'm too lazy to do the math... but this is close to a COP of 1 anyway.

I bet the owner googled and saw someone in CA said in a youtube video that a heatpump is the way to go.

 

[nuuvox000]

This is actually for a University and they have a whole team of people so I think mostly they're trying to sell "efficiency". Sounds like they also don't have a lot of electrical power available for some reason...
Looking at the data on the unit, it looks like it has a COP of 2.5 down to 5 degrees F ambient so not too bad honestly. Maybe because it uses CO2 as the refrigerant.

 

[EnergyProfessional]

Should review with manufacturer if that application works. May use multiple units if they only come in some size. Look into capacity at the design temperature. If they list 250kBtu/h, that may be at 50°F. so at 0°F it may drop to half or less.
Depending on how many days it is 0°F, some electric heat may be OK for some days to save equipment size. Obviously they need the power required.

Is the evaporator actually outside? the few water heaters i know have the evaporator on top and extract heat from the room air, which obviously won't work well in heating climates.

 

[nuuvox000]

Agreed, I should have the manufacturer take a deeper look into it just to be sure. The capacity does drop to about half at these low temps but I've accounted for that. Yep, the evaporator is outside. I would agree that backup electric heat would be great (it would eliminate one of the units) but I think they're really trying to prove something on this project. They seem to really want to say that it doesn't use electric or gas heating.

I looked into the indoor evaporators but it's such a high capacity that we would have to heat the room with VRF fan coils which didn't make a lot of sense.
Thanks for the tips.

 

[EnergyProfessional]

I'm curious how they would be able to say they don't use electric heating when they use a heat pump. How does the compressor turn without electric motor? Gasoline engine, or do they have a horse carousel turning the compressor?

Nest thing, use an electric generator. The generator will be driven by an electric motor. You know, need to claim you don't use fossil fuel.

 

[nuuvox000]

Ha ha, electric-resistance heating is what I meant to say but I can offer them a horse-carousel and see if they're interested. Or hamster-wheels in each unit if they want to go with individual unit systems.

 

[PEDARRIN2]

Try Watts Lync and Colmac.

They would be ideal where the load is large and has a relatively long (hour or two) duration.

 

[EnergyProfessional]

Since that is a University, make the hamster wheel be part of the fraternity hazing process. win-win.

 

[nuuvox000]

@PEDARRIN2, thanks, Watts Lync is the one I'm going with right now. Colmac may be a good option if we go with individual smaller heat pump water heaters.

 

[itsmoked]

I'd militate for a couple of smaller units so you have a graceful failure mode rather than an entire complex losing all it's hot water when one single unit goes down.

Do they not have gas?

It might make a bunch more $$$ sense to put in rooftop solar water heating for nearly free hot water during most of the year and then pay for more expensive HW occasionally.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[nuuvox000]

@itsmoked, we are sizing them for 100% redundancy per our clients direction so hopefully total failure will be rare. They will not accept gas anywhere in the project for sustainability purposes. I had the same thought but they gave us a hard no on looking into solar. Thanks for the comment.

 

[EnergyProfessional]

Solar hot water is a good idea, but you still need a "regular" water heater of the regular size to cover night, rain, snow events etc. From an energy point, SHW can cover 50-70% annually, but not on all days.

Alternatively to SHW, installing PV to generate electricity for the heatpump can be more economical since PV got relatively cheap. But where electricity comes from, is kind of dis-connected from the heatpump since we have the grid as battery/source.

Multiple smaller heatpumps also may work better to have longer run time on each unit (fewer start/stop). Not sure if those heat umps have some sort of variable speed compressor to modulate.

 

[itsmoked]

Yeah.. San Francisco just stated they won't allow gas to be supplied to any new buildings.

I'm saying if you can get existing 250kBTUh units use 4 of them instead of a mythical 1,000kBTUh unit that you end up being the bleeding-edge guinea-pig customer.

Alternatively use insulated storage and some math to get a smaller unit running longer to bank heated water.



Keith Cress
kcress -

http://www.flaminsystems.com

 

[chicopee]

I am not certain that a large unit is the answer. It would be better to have smaller units and the reason is if the large unit needs repair than the downtime may be lengthy especially now with COVID 19. Manufacturers are struggling to get workers.