How Vapor Injection Heat Pumps Deliver 25% More Capacity in Freezing Weather | Joshua Souders-Part 2

what's up guys so in part one with Josh sters from Copeland we talked about the different compressors single speed two-stage and variable speed so in part

two Josh is going to talk about how the variable speed and Vapor injection that technology is it's not new but it's used in in heat pumps so we can get maximum

capacity in the the heating cycle he's going to go on and talk about how variable speed compressors use this Vapor injection and this is the reason why heat pumps are so effective these

days if you get a cold climate inverter heat pump and how it can heat when it's super cold outside when I say super cold I mean that's a very relative term but anyway we're going to get back to Josh guys this is the HVAC not all podcast

I'm your host Gary mccre this podcast is sponsored by cool a Products master cintos and supplyhouse.com go to the show notes and click on the links to

check these guys out let's get back to the variable speed compressor now give us just the basic rundown of of of what it is yeah so you know and I'll keep this

limited to what I would call like a true variable spe compressor so not like a you know a fix speed compressor that's using an inverter of some sort okay you know typically a true variable speed

compressor or what I would call through variable speed compressor you know I have a permanent magnet a rare earth metal you know magnet motor in it to kind of optimize for efficiency but

generally I mean you're pairing a compressor compressor with an inverter the compressor will not function like if you just H up a you know to three-phase power won't work without an inverter you

know and that inverter is sending you know it's basically controlling the pulses that of of power that are going to the compressor you know to regulate a certain speed and depending on the

frequency that you know that that's going uh running at you know you know for instance like our products you know run between 900 and 7,000 RPM like our

current product right and so we'll send pulses at different frequencies to achieve a specific speed and that speed you know the OEM who designed that

system has correlated that speed to a specific you know capacity to meet a specific demand and and so really the advantage of that is you can run exactly

how fast you need to to not shut off you know ideally a variable speed compressor and an ideal world runs 24 like to you your point about the digitals it runs

247 365 never shuts off always continues to run that's the idealized world so you always get you know you always have you know whether in even in heating cooling

right you know regardless it it would continue to run and never quite me the capacity demand but be very close so you have like almost no temperature swing

and you get you know maximum dehumidification maximum comfort so that's the icon of idealized world and and structurally I think there's a couple things to think about variable speed compressors versus like a fixed

speed because there are it does come with some technical challenges and I think a big one is when you're operating over this large frequency range right you're running you're operating you know

sometimes slow sometimes really fast oil delivery becomes uh a major concern uh not only oil delivery internal to the compressor but making sure oil is

getting back out from the system into the compressor so there's a couple things so we design our you know our fixed speed products or our two-stage

products our crank chefs inside have a geometry internal drill to that crankshaft that's designed and optimized for that 60 htz and to pull oil up the

shaft without you know any sort of pump or anything when you get in variable speed you know optimizing that geometry um becomes much more complex

and so generally you have a positive displacement oil pump internal um to kind of force oil up the shaft it's only variable speed it's only variable speed that has that oil pump

right yeah I mean as far as I'm aware I mean most I don't think any compressor manufa I'll put it this way I don't think any compressor manufactur is going out of their way to add cost of an oil

pump if they don't have to like they would of course so of course so yes I I think generally you would only see that either in a a variable speed product or in maybe a different segment so

non-residential like a you know High reliability requirement in like a refrigeration or commercial application you might see something like that but in residential you're not going to see it let me ask you want this question then

because depending on the manufacturer that that gets your or purchases the compressor from you guys and puts it in their their their unit because I've seen this with different types of vrf and

stuff like that where it will have an oil return sort of program where every once in a while if it's running on low speed it'll be like hey let's fully ramp up and bring some oil back now

with the positive displacement pump is that even necessary it is actually not in every case but really

depends on a lot of factors with the SI more the system so every compressor pumps oil out right every compressor in

the gas stream of refrigerant um that's going out into you know through the condensing coil uh you're going to have oil uh Mist vapor in that that stream of

gas and so when you you think of system design we always look at like oil C we could we call oil circulation rates oil pump out those kind of things and so a

lot of times what you see with variable speed is when you run really really slow um so you're running really low mass flow through that compressor for a

long period of time what happens is you're still pumping that oil out into the system but there's not enough mass flow in the in The Vapor like the gastri is moving fast enough to get it to come

back into the compressor so it kind of sits out logged out in the coils and so a lot of times the OEM will make the decision to have this oil boost cycle as

you said where it it ramps up for a specific period of time every you know it's run low speed for so long in order to force that oil to come back into the sump to make sure that that pump can

keep feeding the bearings okay cool yeah that's that's really important that's a really important feature of the OEM to put into their planning and and operation right yeah it has to do with

you know it's all on their control logic and algorithms now you know is obviously the oams are going to do all their engineering analysis and testing them

you know for each unique system and and it really is very system dependent so depending on what kind of coil they're using how big the coils are all those kind of things can affect it so it's

it's not really a straightforward like you just you know every OEM needs to do it you know this way uh they all kind of have their unique way now we do provide

guidance uh you know in our app so we have a what we call application uh bulletins that we we publish out there for the oems and we will provide guidance if they run you know if you run

a certain period of time at this we recommend an oil boost cycle of some sort to bring oil back to the compressor gotcha okay cool let's talk about the vapor

injection then we'll just get in then it's it's kind of a lead into the into the heat pump and and how heat pumps are designed to run in cold climates these days so talk about Vapor injection on a compressor and what it is and and what

like its function is and what it's supposed to do and all that so Vapor injection I think you know for for any of your listeners that have you know they might work at uh you know

contractors that work in multiple segments of the market of the atak industry Vapor injections and Technology that's been used in refrigeration for

quite a while now it's just kind of now starting to make inroads in residential and really the goal is increase capacity and increase efficiency for heating

applications that's the primary goal you know our you know our analysis and uh testing shows you know up to like a 25%

increase in capacity and 10% increase of efficiency when vapor injection is on so it's a it's a pretty big factor it's a way to get extra capacity

out of the same footprint um you would you know that you wouldn't be able to get otherwise and so the way Vapor injection works is basically you're

you're pulling gas off the condensing line you are running it through a expansion device and then you're running it through a heat exchanger or you can

run through a flash tank it can work that way too but you are bringing that gas you're then bringing that gas back and direct and directly injecting it

into in in our case into the scroll Pockets so you have the normal gas that's coming from you know that's coming back into the system you know

it's got a certain superheat a certain you know subcool it's coming back in going through the normal compression cycle and then in the middle of that you're injecting this gas into one of

the pockets uh the subcool gas to get this increased capacity and increased efficiency and you also do get can can I ask you a question before you go on I just where is that piped from that that

Vapor injected gas right into the scroll set where is that piped from directly so the line so the vapor line comes off your condenser goes through an expansion

viice goes through an evaporator and then it comes from the evaporator that comes from that heat exchanger and goes straight into the compressor there's an extra port on the compressor that it connects to there's people listening

going why is he calling it a heat EX Cher because they're thinking of a furnace he's calling it a heat exchanger because it's a heat pump and outdoor you can't really call one an evaporator because they they interchange depending

on what you're doing right so maybe I can send you maybe a graphic that you could I I don't know if you you have that capability to post it that shows kind of a simplified version of what

that system architecture looks like so there is actually an extra heat exchanger inside yeah it's it's inside

the system that you use to basically that expanded gas gets heated by the gas coming off your condensing line so it

gets like reheated and and you're doing that to control the the quality or the super heat I guess you could say of that extra gas that's going to get injected into the compressor the diagram would

help I'm a visual learner like most so so if you could send me that that would be amazing and I can utilize that as part of posting about this podcast you're basically doing subcooling is

what you're doing okay all right so I'll get that diagram okay so let's we have the vapor injection right into the scroll set yeah so as I said that when that gets

injected you're you're basically putting that extra gas in there it's it's a you know that gas I think there's a couple things obviously as I said increases

capacity increases efficiency also does help control discharge temperatures so you know typically there's a limit on you know that discharge line temperature um that we want to maintain so oil

doesn't start to break down and you just don't start to get you know ging in in excessive wear and so that also will help you know as you move into the upper left-and corner of of an operating

envelope of a compressor particularly for heating you know that's generally where you operate is that upper leftand corner High condensing low evap it will help keep the components inside cool it

also helps with that quite a bit okay awesome now how does is this used only for heating The Vapor injection portion or are they using it in cooling as well

for residential I would say that it's primarily only going to be used for for heating um for heating okay all right now in other segments I think it's used

more for the reliability aspects the discharge temperature control but for residential air conditioning it will be used primarily for heating okay and and

this Vapor injection allows a heat pump to run in low ambient conditions just one part of it or is this like the basic heart of of how we can do this no so it

is just one part of it and so as I said about a 20 up to 25% capacity increase and that in particular you know when you're going lower ambients and you

activate that Vapor injection that is generally how a lot of oems are targeting those ultra low ambient temperatures so I'm not are you familiar with the doal climate heat pump

challenge I don't I've never heard of it no okay so a couple years ago the department of energy put out this Challenge and and really the goal of the

challenge was to see what's possible like how you know how effectively can a uh OEM design a heat pump that is meant

almost as a furnace replacement I I would say that's kind of like the Target right okay not necessarily the reality but that's kind of the goal on the Target and so they put out these targets

or these requirements and and one of their requirements is uh 100% capacity at 5f and what I mean by that is you know whatever your capacity at your

47f rating point you know 47 degree whatever that heating capacity is they wanted to ensure the OEM would have to provide 100% of that you know that same

exact capacity at 5 Ai and so because generally I think and historically this is you know what you brought up much earlier when we started off is as you go lower in ambient you know you get this

get kind of drop off in capacity and yeah and the goal for the do Co climate heat pump challenge was to prove that you know through their Partners in this which are all the major oems that

there's a a technology Pathway to ensure that that fallof doesn't happen or that it could be mitigated to a point that heat pumps in ultral L ambient

survivable and that's funny because if you read specs on low ambient heat pumps I've seen it where they use the 5 degre sometimes it's actually 4 degree and it it says at four or five degrees

basically it runs at 100% capacity and that's after that is when you start seeing the dip so that's all because of of what you just explained yeah and and

this isn't like a it wasn't a you know it's not a regulated requirement or anything like that this was just kind of a technology demonstration but I think a

lot of the the uh oems are launching or have launched products that meet that um and I think they make particularly a lot of sense in kind of like the mid

temperate areas where you do get days that are in the single digits but it's not you know it's not like your you know your Canada weather right I mean they still will work very well in those lower

ambients and in fact some of the oems you know went above and beyond there was kind of a a stretch goal of like a Nega 100% at like a negative five or 10 F I think it was 10 and you know some of

them did meet that as well and so um I think you you're just seeing this kind of uh this alignment around you know or understanding or maybe a agreement that

historically you know low ambients were a challenge for heat pumps and you know now there's Technologies and products that can actually fulfill or not have

those kind of historical challenges what do you say to the the ones out there that say heat pumps don't work below freezing I mean because I I hear it all the time

and it's funny because up here in Canada heat pumps are being it's like I said it's minus I don't know if I said this on the recording or not but it's minus 11c today and I've installed heat pumps

in the area and I'm not getting calls today that the house is cold so what what do you say to the people that have this misconception that heat pumps can't

heat in these types of temperatures yeah I think you know one of the first things is I think a lot of people that that say that often times at least when I've talked to people it's

it's a existing misconception or preconception they had from a heat pump they installed 15 years ago or products they work with 15 years ago and and back

then in particular O's just kind of you know cooling was still the major Focus uh heating was kind of just like ah you're gonna kind of get you know we'll throw it on there you'll get what you get but they didn't really optimize they

weren't really focused on it it was just kind of like a nice to have that they would they would add on right and and so not being optimized not the algorithms

and and all that stuff weren't really optimized very heavily for heat pumps and I think with the focus and the market developing around heat pumps I think you know all the aliums have put a

lot of focus and attention on you know the Comfort aspect of heat pumps in particular the and you know that obviously directly ties to be able to provide you know ethically heat when it's really cold out right it wouldn't

be very comfortable if you weren't getting heat so I think there's been a lot of improvements now that obviously you still have this drop off as you get colder and colder in the ambient

temperatures you know you won't be able to provide capacity versus a traditional gas furnace where you know 60,000 BTU furnace is always going to be 60,000 BTUs no matter what it's always gonna

you know provide that much to the facility where versus you know you actually have a drop off this curve and heat pumps it does exist now as I said a

lot of that's been mitigated now you know it really depends on the technology that's in the base fump as well you know we've talked through all these Technologies you know there are certain advantage and disadvantages in heat pump

applications for some of these Technologies for instance variable speed systems true variable speed systems generally have the capability to over speed which means they can go above that

60 htz right being able to do that you know a lot of them run in heating they'll run you know if they're running

3600 to 4500 RPMs to provide capacity in cooling they're running like 7,000 RPMs or up to 7,000 or maybe even a little bit higher to provide capacity and

heating so this over speed capability and variable speed is definitely uh huge game changer or shouldn't say Game Changer because it existed but it's definitely a key technology that enables

lower ambient heat pumps and so you know I think the vapor injection is just the next step or the next extension of how do we get even more out of it Beyond variable

speed I mean I have a I had a customer and he opted out of going with backup heat or auxiliary heat he wanted to just run and Gun and see what happened and he

called me last year in February and said hey uh my heat pump can't keep up but it was minus 14 Celsius at that point so he was fine up until that point and then

but he was still getting heat he just couldn't get I think his thermostat we're talking in Celsius again and I'll convert it to so I think he he was setting his thermostat for 21 degrees

Celsius which is around 7172 is something like that but and he couldn't maintain that temperature but he was only a couple degrees below it like he was he was at 19 or something like that

he's just like I think my heat pump is struggling at minus 14 or 15 or whatever it was outside C he goes I think I need to add the the auxiliary heat strips in

now so I went back and did it for him and fall here just so he could and he wasn't living in the house at the time so it wasn't a big rush or a big deal that's why it was done in the fall uh

but if you can heat a home and to to that type of weather outside with a heat pump that's pretty Advanced as far as technology goes as to what you're saying

from 15 years ago a lot of people really like the dual fuel aspect because they have a lot of trust in in a gas furnace because gas furnaces high efficiency gas

furnaces are pretty reliable I mean they they have a lot of reliability and like you said the capacity is the capacity it does not change so if you're ever having

issues with your your inverter style heat pump you can always switch over to your gas if if need be but I think there's a a true Advantage when it comes to the cooling aspect like we've talked about when you put in an inverter style

heat pump is because you have those long run times you dehumidify better your Comforts better you don't put as much wear and tear on the compressor

the argument and I want to ask you this before we head out the argument from a lot of technicians installers online is my customer doesn't want to pay the

extra cost for an install like this when there's cost savings on their bills might not reflect that over the course of time and that's that's one of the

arguments I I get it there are people out there that will pay top dollar for Comfort like there's people out there that will okay I can give you a a four Explorer or I can give you a Ford

Expedition which one do you want well a lot of people will choose the Expedition because of a high level of comfort just driving that vehicle I mean they're still getting from A to B right but they

like the Comfort they like the heated seats the heated steering wheel how it's high up how It's the leather seats are wrap around your body there there's people that will pay top dollar for comfort so tell me what you think about

the texts that complain about the cost of install versus the customer that wants to pay top dollar for high level comfort you know there's a wide variety

of in user customer you know desire right in it but I think at the end of the day you know even your base your heat pumps have massively improved from

years ago and I think to your point it is a big headwind you know or Road blog for heat pump adoption the extra cost at least up front initial calls you know

now in in areas where there's not natural gas um I think the payack back is is much better in a heat pump right if you're in you're in Florida you're not you know how how many days out of

the year are you going to run that heat pump you know how many days is it going to be below freezing you know might get one or two I mean why would you worry about you know like having to you deal

with like an electric furnace or or some of the other alternativ just put a heat pump it's it's going to pay for itself eventually you know there are a lot of incentives right now for heat pumps um

so I think you know when you look at upfront cost I think all all the contractors um should be at least aware

that you know there's you know up to like $2,000 right now available for you know heat pump you purchases a tax

credit more that in some areas we we had we had five or $6,000 credit last year yep so that's so depends depends where you live yep it's that's Federal uh there's $2,000 for the heat pump itself

there's up to $88,000 for I think in just in general this is all federal right now Energy Efficiency upgrades I think you can get up to like $600 for even like the electrical

upgrades or some of the electrical upgrades associated with you know a heat pump install so there's a lot of incentives at the federal level and then to your point there's tons of like

Regional and state based incentives depending on where you're at that can really really mitigate you you know the extra cost of a heat pump you know for

instance you know you can get a two-stage or even a kind of a a more budget friendly variable speed system in some cases for the price of a fixed

speed system in some cases now right why wouldn't you you know get the you get the heat pump kind of as a gim me in those cases because there's so much yeah

andc of dollars right now behind it so I I think you know definitely you know I think most people understand that the heat pump the initial upfront cost can be intimidating it can definitely be

headwind to adoption but I think at least right now there's there's a lot of things to mitigate that and and so I think for your customer you know as you said there's there's a lot of other

options too as far as architecture you know you know we have a lot of people around our area that use propane all right and so propane's a huge one I I I

know some people that are paying a ,000 dollar a month in their propane bills and I'm like you are a definite candidate for a heat pump and then they

go well isn't it like $50,000 $60,000 I go no that's like a Geo I mean you don't you don't need Geo anymore with the technology that we have right yep and

you know we've got there's several that we you know that work with me they're on propane they live outside of gas delivery and you know there I think every one of them's on heat pump because

they're just like it's just too expensive to heat and cool with propane the one guy told me um he's only ever had his he's got a propane pup actually

I think he he said that he's only ever had the propane backup kick on like two or three times in like the last five years wow very cool awesome man so all

right well I mean Josh this has been cool I really like the the beginning when we talked about the three compressors and how we set it up uh to to get to where we got in this conversation so I mean it's it's been

almost an hour here of of discussion so I I don't want to take any more of your time because I think we've covered what we got to do here and it's I learned some stuff audience uh I hope you did and I hope you you guys stuck around to

the end because this was a nice talk thanks Josh I appreciate it yeah and I'll I'll send you that graphic for Vapor injection I I can see a couple Clips too of the vapor injection how it

works in the scroll and then how two stage works as well because I think it might be um talking through it is not as good as a visual for sure yeah yeah would appreciate I think the audience

would appreciate that visual too so yep thank thanks man I appreciate it yep have a great day