Aqua Booster vs Indirect Water Heater

Reply

  #1  
Old 02-01-07, 12:43 PM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
Aqua Booster vs Indirect Water Heater

i am looking at buying a house in CT with a 1990 New Yorker oil fired boiler (dry based - 133000btu) that has baseboard heat (2 zones)and a tankless coil for domestic hot water. serviced yearly by the oil company since they installed it. it looks in good shape but the dometic hot water is inadequate for me.

i tested the sytem and if you turn on two hot water faucets at once, the pressure drops and the water flows much slower than when only one hot faucet is open.

would an indirect water heater (50gal) be better than using the old coil with a booster? i want to be able to use two showers at once or at least one and run the dishwasher without running out of hot water.
 
Sponsored Links
  #2  
Old 02-01-07, 01:45 PM
Member
Join Date: Sep 2006
Location: usa
Posts: 83
50gal indirect is a lot of hot water. I think it should do it for ya. Especially if you keep your indirect at 130-150F and have HW supply from it trough a mixing valve at 120F
 
  #3  
Old 02-01-07, 01:50 PM
Who's Avatar
Who
Who is offline
Member
Join Date: Jan 2006
Location: San Jose
Posts: 2,175
Yes, far better. The tanks are pricy and need to be piped but definitely the best long term solution.
 
  #4  
Old 02-02-07, 02:39 PM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
thanks for the replies.

what would be an argument against a 50 gal aqua booster?

i have gotten various opinions about this, and was even told that my boiler would need a priority control because it is not large enough to supply both domestic hot water with an indirect and baseboard heat at the same time.

also, what do you think might be the cause of the pressure drop along with the water becomming luke warm after a couple of minutes of flow?
 
  #5  
Old 02-02-07, 11:08 PM
Who's Avatar
Who
Who is offline
Member
Join Date: Jan 2006
Location: San Jose
Posts: 2,175
"and was even told that my boiler would need a priority control because it is not large enough to supply both domestic hot water with an indirect and baseboard heat at the same time"

Do you or the person who told you this know what the heatloss calculation is for your home?
 
  #6  
Old 02-03-07, 04:55 AM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
It is a matter of what you can spend. If you can afford the 50 gallon indirect, go with it. 30 is probably adequate but if you are planning on stressing the hot water delivery, then get some storage capacity. You probably will need a priority control too but the only way to know for sure is to install the indirect and try it. If you run out, install the priority control.

Tha systems I prefer make 2gpm with a plate heat exchanger and use a 40 gallon tank. I have never in 19 years had someone complain of running out of hot water. That would be 160 gallons per hour. Your coil should make that because it is probably rated at twice that and would never make 4 or 5 gallons continuously anyway.

Ken
 
  #7  
Old 02-03-07, 10:53 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
Originally Posted by Who View Post
"and was even told that my boiler would need a priority control because it is not large enough to supply both domestic hot water with an indirect and baseboard heat at the same time"

Do you or the person who told you this know what the heatloss calculation is for your home?
no one has done this calculation. the tech asked me about my boiler capacity (133,000 btu) and off the top of his head said it would most likely need a priority control due to its size.
 
  #8  
Old 02-03-07, 11:12 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
Originally Posted by KField View Post
It is a matter of what you can spend. If you can afford the 50 gallon indirect, go with it. 30 is probably adequate but if you are planning on stressing the hot water delivery, then get some storage capacity. You probably will need a priority control too but the only way to know for sure is to install the indirect and try it. If you run out, install the priority control.
what would be a typical price difference between a booster and an indirect? would a booster do a good enough job even though i am relying on the old coil?

i could post some pictures of the system if it would help. let me know how to do this if needed.

Originally Posted by KField View Post
Tha systems I prefer make 2gpm with a plate heat exchanger and use a 40 gallon tank. I have never in 19 years had someone complain of running out of hot water. That would be 160 gallons per hour. Your coil should make that because it is probably rated at twice that and would never make 4 or 5 gallons continuously anyway.

Ken

what brand of system are you referring to that use a plate heat exchanger and could you provide any links? what kind of boiler is used in these systems?

the problem with the coil is that i was advised that it might be clogged due to the pressure drop i experienced when opening two hot water faucets. i think i might not want to rely on it (16 years old) for my domestic hot water needs if i can get a new one as part of a new tank. also, these coils don't have a great flow to begin with. what do you think?

i looked at a weil-mclain gold indirect which seems like a quality tank - not cheap though...
 
  #9  
Old 02-03-07, 11:43 AM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
They don't show the individual components but you can get an idea how it all would go together. They are the same parts they use in the system but can be matched to any system. You probably get as much out of your coil as the heat exchanger supplies and the tank is the key to removing the 'instantaneous' from the coils demand. http://www.energykinetics.com/aproducts.html

I prefer these indirects. I'm not in love with WM for anything.
http://www.crownboiler.com/products/indirect/mega_stor.asp

Use your judgement. I probably have 12-15 of the "hot water helper" packages installed in all kinds of boilers over the years and never had a complaint. You can obvoiusly get 2 gpm through your coil and the circulator won't move much more than that anyway through there so unless you are looking for an expensive project, don't throw the idea out yet.

Ken
 
  #10  
Old 02-06-07, 04:47 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
Originally Posted by KField View Post
They don't show the individual components but you can get an idea how it all would go together. They are the same parts they use in the system but can be matched to any system. You probably get as much out of your coil as the heat exchanger supplies and the tank is the key to removing the 'instantaneous' from the coils demand. http://www.energykinetics.com/aproducts.htmlKen
the tanks they show are boosters which are used with the plate heat exchangers, right? is this all you need to install?
when you say the exchangers are like my coil, i guess you mean if the coil was not clogged as i have been led to suspect due to the pressure drop when openning two hot water faucets or could this situation have some other causes?


Originally Posted by KField View Post
I prefer these indirects. I'm not in love with WM for anything.
http://www.crownboiler.com/products/indirect/mega_stor.aspKen
do you have any idea how much these should cost, installed? - ballpark? this would be the alternative to the energykinetics stuff i guess.

Originally Posted by KField View Post
Use your judgement. I probably have 12-15 of the "hot water helper" packages installed in all kinds of boilers over the years and never had a complaint. You can obvoiusly get 2 gpm through your coil and the circulator won't move much more than that anyway through there so unless you are looking for an expensive project, don't throw the idea out yet.

Ken
i'm not sure i get exactly what your "hot water helper" packages include. if i get an indirect, then i don't need my coil or the heat exchanger, right?

also, if i use a booster tank, i either need to use my coil or the heat exchanger, right?

which type of installation has proven more cost effective in your experience? thanks again.
 
  #11  
Old 02-06-07, 05:36 AM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
The hot water helper using your coil would be several hundred dollars less expensive. If your coil was clogged to the point where 2 gpm would not flow, you would not be using the shower. The difference between using your coil for a helper and using it for instantaneous supply is about 3 gpm. You are correct about the operation but the installation of the indirect requires much more work and piping. Also most indirects are stainless steel tanks and coils and the helper is a 12 year glass lined tank. In my area, a 40 gallon hot water helper would cost about $1000 installed.

Ken
 
  #12  
Old 02-06-07, 06:08 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
i like less expensive, as long as i get the hot water i need. what kind of recovery rate can be expected while heating the booster with my coil or the plate exchanger?

so if the coil is still flowing at least 2 gpm, why the pressure drop when two faucets are opened? can it just not keep up with two hot water draws? is there something else that should be checked?
 
  #13  
Old 02-07-07, 12:41 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,467
Upvotes Received: 16
Why the pressure drop when two faucets are open? Probably because each faucet alone takes anywhere from 1-1/2 to 3 gallons per minute.
 
  #14  
Old 02-07-07, 07:31 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
Originally Posted by furd View Post
Why the pressure drop when two faucets are open? Probably because each faucet alone takes anywhere from 1-1/2 to 3 gallons per minute.
ok, but it also causes the temperature of the water to decrease so that it is comming out of both faucets as luke warm. is this a different problem?

this may relate to my other question about recovery rate with using my coil with a booster tank.
 
  #15  
Old 02-07-07, 05:39 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,467
Upvotes Received: 16
"ok, but it also causes the temperature of the water to decrease so that it is comming out of both faucets as luke warm. is this a different problem?"

Nope, same problem.

With a tankless coil the temperature rise (the amount the water is heated above the cold water temperature) is inversely proportional to the rate of flow. In English that means that the water will come out of the tankless coil hotter if the flow is low (one faucet) and it will be less hot if the flow is greater as in using more than one faucet at the same time.
 
  #16  
Old 02-08-07, 05:13 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
so basically, this is inherent for this type of system then. that is disappointing. why would anyone want this type of system anyway? what a pain.

the only thing i don't get then is, how well would the coil operate in a hot water helper system a suggested by KField? i know he said that all his installations had a favorable outcome but it seems the coil would not be very efficient when it came to heating the water for the tank. is this thinking incorrect?
 
  #17  
Old 02-08-07, 05:45 AM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
The problem is not whether your coil can still produce hot water, it is how much it can produce. The rating on a brand new coil might have been anywhere between 3.5 and 5 gpm. The fine print is that the temperature rise is limited and incoming water is coldest in the winter at the same time you use the boiler for heat. Unless you keep the boiler at 200 degrees, you will probably never achieve the rated output of any coil even on day one. As a boiler ages and especially when it gets installed in a system full of oxides and crud from a previous system, the coil gets sludged up on the outside. That acts like insulation preventing heat from the boiler water from getting into the domestic water. Now couple that with the fact that we don't have any idea what your water pressure is in the house and you could have a dartboard with gpm numbers on it and be as good as we will be at knowing the capacity of the coil today. 2gpm is a safe number considering a 50 degree temp rise. But here is why I say the helper is adequate. If you have a 40 gallon tank that is full of water at a temperature you desire, how much more than that do you need at any given time? If you had a 40 gallon electric water heater you would get only 40 gallons and then cold water until it recovered. If your coil supplies 2 gpm and you start with 40 gallons in the tank, you should end up with 160 gallons per hour. Far surpassing the electric water heater. It comes darn close to an indirect without all the piping. If you are going to use an indirect, then why not install a good boiler at the same time? You can either repair the problem with a sensible low-cost approach, or go all the way. You will have to make that decision.

Ken
 
  #18  
Old 02-08-07, 06:22 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
i like your comments very much and apeciate the help in understanding this issue.

If money were unlimited then i would just go with a whole new system. i was quoted $7000 for a system 2000 from EK, installed. I was also quoted $2000-$3000 for an Weil Mclain indirect

The oil company that originally installed and maintains the boiler originally recommended a 50 gal TFI Everhot booster for $1300 installed or if i wanted, $1800, installed for an indirect, the name of which escapes me.

i was originally aprehensive about the booster so i started my research.
so here is a synopsis:

1) I gather then that installing a new plate exchanger with a booster wouldn't really be helping me even though the coil is aged or is it advisable to delete the old coil from the system?
2) Priority contol would still be needed with the booster?
3) Mixing valve not needed due to aquastat on tank.
4) what to check to estimate longevity of existing 1990 boiler?
 
  #19  
Old 02-09-07, 08:35 AM
PTN
PTN is offline
Member
Thread Starter
Join Date: Feb 2007
Posts: 31
  #20  
Old 01-05-10, 05:54 AM
Member
Join Date: Jan 2010
Location: PA
Posts: 1
Hot Water Helper

To quote Ken

The hot water helper using your coil would be several hundred dollars less expensive. If your coil was clogged to the point where 2 gpm would not flow, you would not be using the shower. The difference between using your coil for a helper and using it for instantaneous supply is about 3 gpm. You are correct about the operation but the installation of the indirect requires much more work and piping. Also most indirects are stainless steel tanks and coils and the helper is a 12 year glass lined tank. In my area, a 40 gallon hot water helper would cost about $1000 installed.

Ken

I am looking for a contractor that covers Jamison, PA 18929 to do just this, any ideas ?
 
  #21  
Old 01-05-10, 01:31 PM
rbeck's Avatar
Member
Join Date: Jul 2007
Location: Pennsylvania
Posts: 2,444
Upvotes Received: 1
I hate to do this to you but most here know I always look at things a bit different.
Question 1. Is the complaint strictly a temperature issue or also a flow issue when you try two showers?
Question 2. What are the control settings in the big gray box on front of the boiler?

First off you would never use that coil in the boiler for anything other than a boat anchor. In fact it would not make a good anchor either. Two downsides of coils in boilers is you have to keep the boiler hot all the time and they calcify and restrict flow. They should be outlawed as they are in most countries in the free world.
I would bite the bullet, eliminate it and go to something else and cold start the boiler. See this link http://www.comfort-calc.net/Domestic...r%20_Coil.html The fuel savings alone would pay the difference in a few years. I am not a fan of aqua-boosters as they need to maintain the boiler temperature.
A properly sized and piped indirect will save you money for many years to come.
As far as priority......Your choice. The only time priority is actually needed is at design outdoor temperature and a properly sized boiler or a very high hot water demand like a large hot tub with a high gpm water flow faucet. I have some jobs where they used priority controls and have a hot tub. They turn on the priority switch when the hot tub is going to be used and back off when the hot tub is not going to be used. Granted the hot tub in these situations are not used everyday.
 
  #22  
Old 01-05-10, 01:37 PM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
Energy Kinetics sells the whole package for using your coil so maybe an EK dealer is th eplace to start. They call it the Hot Water System "A" package. I would also suggest that you look into installing the Beckett Aquasmart control at the same time. It will maximize the savings by allowing you to set the low limit at 100 degrees and even put the storage tank on priority without adding a lot of high tech wiring. It has the Heat Manager control built in is a good value.

Ken
 
  #23  
Old 01-05-10, 04:43 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes Received: 1
You guys do realize this thread is from 2007, right?
 
  #24  
Old 01-05-10, 05:30 PM
KField's Avatar
Member
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
Just like my Woodstock tee shirt, I like old threads. We'll beat this horse till it's dead.

Ken
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes