Heating Help

« Back

NRT_Rob

Joined on August 20, 2009

Last Post on May 17, 2012

Contact User

wait a sec

@ February 25, 2012 4:09 PM in are there any electric combiboilers sold in the U.S.?

200KBTU/hr is a large amount of domestic hot water. Even here in maine that would be almost 7 GPM. that's a very large hot water draw... most combi boilers are only delivering about 100kBTU to the water for a 3.5 GPM domestic demand, much more reasonable.

you don't see a lot of electric combiunits as the electric units are often not much more money than the heat exchanger assembly would be. could usually just do two units and, if amperage were the problem, lock out the space heat unit when the DHW unit runs.

Or, maybe you can use an electric boiler for heating, and use an indirect just like a regular boiler usually would.

in most cases

@ February 23, 2012 10:23 AM in Boiler ? Water heater?

you can do better for efficiency with a mod/con boiler than a water heater... you can run them colder, especially on low temp heating systems.

truly high efficiency water heaters have some advantages in that it's hard to short-cycle them, so that's nice.

but never, ever run them in an 'Open' or "Open direct' configuration. that's a horrible idea.

I agree

@ February 23, 2012 10:19 AM in Oil vs. gas heat dilemma

there have been some real lemon boilers and there are even more lemon installs out there... I still run into massively oversized mod/cons with no outdoor sensor installed all the time! it's criminal. and man, NYC seems PACKED with installers of that mindset.. astounds me every day.

but that's a "you chose a bad installer" issue, not a boiler issue. I guess if you're going to hire a hack, it's harder for them to screw up cast iron and it's cheaper if they do, that's true.. but I don't think I'd advise people (who are listening to advise) to go cast iron as a result... I would advise them on how to pick a decent installer. the decent installer's job is to know what are good boilers.

it's not really that hard. do they ever do heat load calcs? do they use outdoor reset?

those two questions knock out most of the hacks immediately.

the price range you are considering

@ February 23, 2012 9:00 AM in Cost Effective Radiant Floor Heating System For Soon To Be Home

depends on what "really expensive" means. If you're doing a lot of the grunt labor this could be in range for you, especially if your electrical rates are low enough to consider an electric boiler for heating as some others in Oregon I've worked with have. That can really reduce the initial cost.

devil's in the details though. Load calcs would be necessary to know what kind of radiant emitters would even work for you and that is what drives a good chunk of the cost.

i don't find this argument compelling

@ February 23, 2012 8:53 AM in Oil vs. gas heat dilemma

for several reasons.

1. not all mod/cons are unreliable or have short lifespans. there are bad units, and there are good units. Get a good unit with a stainless steel HE.

2. not all cast iron beasts last for 50 years either. I've seen many die in 10-15... the same lifespan you consider inadequate for a high efficiency appliance. Cast Iron does not automagically mean "built to last".

3. Real world efficiency difference, atmospheric cast iron to sealed combustion mod/con, is more like 20% minimum and often more, not a "few" percent. and that ignores massive domestic efficiency gains in the summer... cast iron without purge control is 25% efficient all summer for DHW if you're lucky. mod/con is double, apples to apples.

4. who has $400/year in mechanical failures??

Cast Iron is a dinosaur that needs to finish rolling over and dying. There are several brands of mod/con out there with excellent service records. Pick one and roll...

sorry

@ February 22, 2012 10:12 AM in Utica Cast iron baseboards?

I don't know CIBB parts that well. but if your utica/burnham pathway to clarity doesn't work out drop us a message with some specifics and I'll see if our distribution chain has anything.

and that

@ February 22, 2012 9:05 AM in Hot Water Issue

is exactly what we would recommend.

multiple story unpressurized systems are no fun.

be sure

@ February 22, 2012 9:04 AM in Utica Cast iron baseboards?

room by room load calcs are done in the new house. You have an opportunity to size your BB right only once before it gets a lot more expensive later.

questions

@ February 22, 2012 9:00 AM in Cost Effective Radiant Floor Heating System For Soon To Be Home

what is your square footage.
Where are you.
what kind of home construction/insulation are you going for?

these are starting points but no answer can be definitively given without load calcs.

questions

@ February 22, 2012 9:00 AM in Cost Effective Radiant Floor Heating System For Soon To Be Home

two posts for the price of one!

what are

@ February 22, 2012 8:57 AM in Heating Edge baseboard with geothermal ?

the numbers he's giving you per foot now? that really sounds awful...

does the remote access switch close a relay continuously?

@ February 22, 2012 8:56 AM in Tekmar with Carrier Infinity control

if so, it should work. the 480 can take 3 relay demands and, in combination, receive up to 8 different "scene" commands. according to the tekmar data brochure on the 480 the relays can be dry contact or 24v powered.

default with no closed contacts on the unit is "scene 1" or normal.

are you saying

@ February 22, 2012 8:52 AM in Oil vs. gas heat dilemma

if you left it in the ground it would not have leaked, ever?

output charts say

@ February 15, 2012 9:29 AM in Altherma Measured COP

the 030 unit can do 122 degree outlet temp all the way down to 5 deg F... 14.5kBTU on the heat pump plus 3 or 6 kw on the backup available. 122 is the max temp on this unit.

the 054 can put out 113 from the heat pump only (higher, if backup comes into play) down to 19 degree outdoor (29kBTU on the heat pump, plus 3kw or 6kw backup).

I am strongly considering playing with air handlers and fan coils with reset. If Geo guys can run their air at 100 degrees... why not us?

wrightsoft

@ February 11, 2012 5:03 PM in Altherma Measured COP

if you can do the heat pump in wrightsoft, the altherma has its own selection software you can use for its numbers.

If you don't have it, email me the heating/cooling load, water temp at design (heat/cool), and project location and I'll run it for you. won't be able to until monday though.

tricky

@ February 11, 2012 12:14 PM in Altherma Measured COP

Can you estimate usage or cost with the standard heat pump? If it doesn't have software then this would be a manual exercise with bin data for your area, you'd need to know the load you were meeting, and manual COP/Electrical consumption calculations. it's a bit of work but not too bad if you know the heat load and how the heat pump performs at various outdoor temps.

if so the altherma selection software can compare to straight electric, gas, and oil, and it can give you total consumption numbers as well. for part load scenarios, where one altherma can't do it all by itself, I can help if you like. the "hackaround" for the selection software isn't very good for that.

hold on

@ February 6, 2012 9:43 AM in Turning outdoor reset advice

"boost" is the "don't call me back to fix this" setting. it's not a good setting if you are actually trying to maximize your efficiency. Don't use it.

Setbacks reduce comfort. You should be able to find a comfort balance at a more consistent temperature, but if not, you need a programmable thermostat and you can experiment with different on times, or use one with an "optimum start" feature. if you must set back don't worry about it taking a long time to get out of setback.

I would start with 95/65 and I don't remember where you are located... not sure if 16 is the right design temp for you. but if it is, I would scream it down to 140 based on what you're saying for footage and square footage... let it go for a couple of days and see if you fall short. If not, I'd turn it down to 130. If you do, turn it up to 150.

trial and error is easy when you're on site and motivated.

it doesn't really matter that much

@ February 6, 2012 9:35 AM in Radiant circ

as long as the expansion tank is on the suction side of the pump and is not on the other side of the "load". i.e. if you trace back from the pump suction inlet, you should hit the expansion tank before you hit the radiant loops/radiators or the boiler.

supply side is slightly better but as long as it's not expansion tank > loop field > pump you'd be ok. If it is expansion > loop field > pump then you're wide open for major air issues.

large tempering valves

@ February 1, 2012 9:50 AM in snap/banging sound from PEX, doesn't keep up on cold nights upstairs

are very, very expensive. small ones like you have are very restrictive. lots of tradeoffs.

slow acting zone valves will not help expansion noises appreciably. might make some difference.

I have to admit I still can't follow your piping to tell if the 3 way valve is piped in properly. bit of a nest in there...

answers

@ January 31, 2012 10:24 AM in snap/banging sound from PEX, doesn't keep up on cold nights upstairs

1. yes, staple up systems can chew through pex over time. one of the many reasons this install method has fallen out of favor.

2. it would be good to know why that valve is not working. can't tell from your pics what the issue might be. IF the valve really is clogged and not piped incorrectly then you could replace with a motorized valve, yes, but it would only serve the same areas that valve serves, which I would guess is slab only? at the very least you'll want 2 temps if you are doing slab radiant and naked staple up pipe, so you won't do this from one valve, most likely.

3. if the reset curve is set properly you'll have close to constant circulation in the "lead zone" for each water temp nearly all the time.

4. it's highly doubtful you're going to maintain 71 with plateless system. but it's possible.