Maker Pro
Maker Pro

Asking for Recommendations for New HVAC in a Row Home

M

Mike

Jan 1, 1970
0
Steve Spence said:
Or you could move to a climate that doesn't require it. We have never had
a/c, and our heating system (a wood stove) doesn't require a breaker. How
are you with -40 in winter ;-)

Where are you located?
 
P

Paul M. Eldridge

Jan 1, 1970
0
Thanks for the helpful explanation of the trade acronyms. I don't believe
BGE is motivate to clean up their website or otherwise offer needed
information to consumers....

That's my suspicion as well. The sample bill I looked at wasn't a
model of clarity either -- mine is pretty straight forward and
provides a full year's worth of consumption data, including the number
of kWh/day used in each billing cycle; a handy feature that allows you
to track your energy use and gage the effectiveness of various
efficiency improvements (and hopefully provide some measure of
positive reinforcement).
I'm tad pessimistic about deregulated energy and believe delivery charges
and the costs needed to upgraded the power grid to accommodate electricity
from other suppliers. (power grids were never designed to carry power from
multiple vendors FWIW electricity is one of the most unlikely commodities to
be marketed competitively because it cannot be stored or transmitted
significant distances and the stress it puts on existing power grids.)will
cause rates to escalate for both G & E. In some areas the delivery charges
already costs more than the electricity. I agree w/ you it's a crap shoot,
but energy from domestic sources should be more dependable than imported
energy. In one of your earlier posts you made a very good case for the cost
of gas continuing to escalate.

Utility investments in new plant and T&D haven't kept pace with
today's growing needs and deregulation has only made matters worse (as
you point out, bulk power transmission is a matter of particular
concern). Back in the "old" days when utilities earned a rate of
return based on their capital expenditures, the criticism was that we
ended up with a "gold plated" system (and there's probably some truth
to that); now with deregulation, we have something that's more akin to
rusted out scrap metal.

Cheers,
Paul
 
P

Paul M. Eldridge

Jan 1, 1970
0
When does the COP become 1?

Just as a follow-up to my previous reply, I attended a local home show
this past Sunday and picked up some information from one of the heat
pump vendors. It included bin hour information for Halifax, N.S. and
the operating efficiency of one of the display models at each of these
temperature points (sorry, I don't recall the HSPF rating, but I
believe it was 9.0).

Here's the breakdown (all temperatures in Celsius):

Temp Bin / Bin Hours / BTU Capacity / COP

17 / 956 / 42,700 / 3.61
14 / 941 / 40,467 / 3.50
11 / 884 / 38,233 / 3.38
8 / 809 / 36,000 / 3.26
6 / 799 / 33,767 / 3.13
3 / 998 / 31,533 / 3.00
0 / 959 / 29,300 / 2.85
-3 / 528 / 27,067 / 2.70
-6 / 353 / 24,833 / 2.55
-8 / 245 / 22,600 / 2.38
-11/ 174 / 20,367 / 2.20
-14 / 81 / 18,133 / 2.02
-17 / 44 / 15,900 / 1.82
-19 / 12 / -- Off -- / N/A
-22 / 1 / -- Off -- / N/A
-25 / 0 / -- Off -- / N/A

From what I'm told, 99.83 per cent of our heating hours are above -17C
(1F); the point at which this particular heat pump shuts down and the
backup elements become the sole source of heat -- that's just 13 out
of a total of 7,784 hours or 0.17 per cent of the heating season.

Even though our city is colder than Buffalo, N.Y., 93 per cent of the
time, the COP is 2.5 or higher and 70 per cent of the time, it's 3.0
or higher. For those who say air source heat pumps don't work well in
cold climates, I suggest these numbers prove otherwise.

Cheers,
Paul
 
P

Paul M. Eldridge

Jan 1, 1970
0
Hi John,

On Thu, 05 Apr 2007 14:07:56 GMT, Paul M. Eldridge


I'm going to suggest that the numbers don't tell the whole story.
Selecting a cut-off temperature isn't a simple one-dimensional matter.
There are several issues. At what point does the quality of the heat
degrade too much? 75 degree air blowing out the duct work is
unsatisfactory.

When is the compressor exhaust valve temperature excessive? The very
low flow of the refrigerant when all the heat is essentially coming
from the electricity powering the compressor (COP approaching 1) can
allow valve overheating.

What is the humidity in the environment? Even if it's below freezing
if the dew point is close to the dry bulb then the evaporator will ice
quickly and more frequent defrost cycles will be necessary. Defrost
cycles both impact energy efficiency and interrupt the heating.

Compressor exhaust valve heating can be addressed with the proper
design and materials specs. It can also be "addressed" by the mfr
simply accepting a shorter compressor life. Which manufacturer does
what?

There is a major difference between what is technically feasible and
what makes sense. It seems to me that pushing the heat pump envelope
just doesn't make sense. Why deploy equipment that provides
marginally satisfactory heat (at best), is expensive and short lived
when the alternatives are so much better.

I don't work in the HVAC field, so I can't speak to the issues you
raise, but I can tell you that my own experience has been rather
positive and in my conversations with friends and neighbours, my
general sense is that the overall level of satisfaction is quite high.

Just to provide you with some background, here in Nova Scotia, fewer
than 500 homes have access to natural gas at this time, so just about
everyone heats with oil or electric. Nova Scotia Power's residential
rate, as of April 1st, is $0.1076 per kWh and heating oil currently
sells in the range of $0.80 to $0.85 per litre ($3.20 per US gallon).

One litre of heating oil contains 36,500 BTUs and assuming an AFUE of
82% (typical of most new boilers), the cost of oil heat comes in at
$0.97 per kWh(e). Of course, homes with older, less efficient boilers
might pay something closer to $0.12 per kWh(e).

Last winter, my heat pump's seasonal COP was 2.45, so after this most
recent rate increase, my average cost per kWh of heat is 4.4 cents. A
heat pump with a HSPF rating of 9.0 might provide heat for as little
as 3.5 cents. On that basis, the operating cost of a high efficiency
heat pump is roughly one-third that of electric resistance or oil.
Macroscopically, it makes little sense to burn fuel at a power plant,
suffer the inefficiency of conversion to electricity, only to turn it
back into heat again, even if the process has a little gain. Only
with nuclear or hydro generated power would that be logical. If one
is going to burn fuel for comfort heat, why not burn it on-site?

I don't have access to the latest numbers, but NSP's heat rate is in
the neighbourhood of 10,000 BTU/kWh. That would place generation
efficiency at about 34 per cent, with additional T&D losses perhaps
pulling that down towards 31 to 32 per cent. My COP of 2.45 brings
that back up to 77 or 78 per cent and a high efficiency heat pump
might kick it to between 90 to 95 per cent. By comparison, my
five-year-old Slant/Fin boiler has an AFUE of 82 per cent.

Bear in mind not all of our electricity is thermal generated -- about
twenty per cent is renewable and this percentage will grow over time
due to provincial mandates. I've opted to purchase 100% green power
(an additional $4.00 per 125 kWh), so my net emissions are
theoretically zero.
To me, some utility's obsessive promotion of heat pumps for the sole
purpose of taking market share from the other energy sources is at
best unseemly.

I'm not in a position to judge Nova Scotia Power's motives, but I made
a conscious decision to limit my heating oil consumption for several
reasons, not the least of which my fear that a portion of the proceeds
will be used to fund terrorist organizations. Last year, I used a
total of 828 litres of heating oil (220 gallons), the bulk of this
being for the production of DHW. I'm now trying to decide if I will
install a heat pump water heater (a NyleTherm-1), which would cut my
oil consumption by another 500 litres or more; it would also help
minimize my use of the dehumidifier during the summer months (a double
bonus).
I have a modern (<3 years old) heat pump in my mountain home. (Special
circumstance - I found a surplus heat pump cheaper than I could get
the same capacity AC-only package unit. Apparently nobody else wants
'em either.) I hate it. The quality of heat is lousy unless the
resistance heat is triggered and it takes forever to make the place
comfortable even with the ambient as warm as the mid 20s. It's my
third tier heat source, after the wood stove and the propane space
heater, in that order. My impression hasn't changed a bit regarding
heat pumps from my first one >30 years ago.

This is pure speculation on my part, but I can think of a couple
reasons why our experience here in Canada would be more favourable
than your own. One is that our homes are generally better insulated
and less leaky than our American counterparts -- don't quote me, but I
believe our provincial code requires electrically heated homes to be
insulated to R28 / R60 (walls and ceiling respectively) and R20 / R40
in the case of oil. And because our homes have so little natural
leakage, heat recovery ventilators are required by law. The upshot is
that we typically require fewer BTUs to stay warm (well within the
heating capacity of most standard size heat pumps) and there should be
no uncomfortable drafts or cold exterior surfaces that would
compromise occupant comfort. Put another way, the performance bar for
our heating systems can be set that much lower.

Secondly, and perhaps not surprisingly, heat pumps in Canada are sized
according to our heating requirements, whereas I understand yours are
tilted more towards cooling (at least in cooling dominated climates).
My sense is that this "next size up" rule helps to minimize the single
most common complaint with heat pumps; that of the so-called "cold
blow".

Cheers,
Paul
 
M

Mike

Jan 1, 1970
0
Paul M. Eldridge said:
Just as a follow-up to my previous reply, I attended a local home show
this past Sunday and picked up some information from one of the heat
pump vendors. It included bin hour information for Halifax, N.S. and
the operating efficiency of one of the display models at each of these
temperature points (sorry, I don't recall the HSPF rating, but I
believe it was 9.0).

Here's the breakdown (all temperatures in Celsius):

Temp Bin / Bin Hours / BTU Capacity / COP

17 / 956 / 42,700 / 3.61
14 / 941 / 40,467 / 3.50
11 / 884 / 38,233 / 3.38
8 / 809 / 36,000 / 3.26
6 / 799 / 33,767 / 3.13
3 / 998 / 31,533 / 3.00
0 / 959 / 29,300 / 2.85
-3 / 528 / 27,067 / 2.70
-6 / 353 / 24,833 / 2.55
-8 / 245 / 22,600 / 2.38
-11/ 174 / 20,367 / 2.20
-14 / 81 / 18,133 / 2.02
-17 / 44 / 15,900 / 1.82
-19 / 12 / -- Off -- / N/A
-22 / 1 / -- Off -- / N/A
-25 / 0 / -- Off -- / N/A

From what I'm told, 99.83 per cent of our heating hours are above -17C
(1F); the point at which this particular heat pump shuts down and the
backup elements become the sole source of heat -- that's just 13 out
of a total of 7,784 hours or 0.17 per cent of the heating season.

Even though our city is colder than Buffalo, N.Y., 93 per cent of the
time, the COP is 2.5 or higher and 70 per cent of the time, it's 3.0
or higher. For those who say air source heat pumps don't work well in
cold climates, I suggest these numbers prove otherwise.

Thanks for posting this. Which HP are you referring to? Do you find a
particularr HP brand "better"
than the others?
 
M

Mike

Jan 1, 1970
0
Paul M. Eldridge said:
Hi John,



I don't work in the HVAC field, so I can't speak to the issues you
raise, but I can tell you that my own experience has been rather
positive and in my conversations with friends and neighbours, my
general sense is that the overall level of satisfaction is quite high.

Just to provide you with some background, here in Nova Scotia, fewer
than 500 homes have access to natural gas at this time, so just about
everyone heats with oil or electric. Nova Scotia Power's residential
rate, as of April 1st, is $0.1076 per kWh and heating oil currently
sells in the range of $0.80 to $0.85 per litre ($3.20 per US gallon).

One litre of heating oil contains 36,500 BTUs and assuming an AFUE of
82% (typical of most new boilers), the cost of oil heat comes in at
$0.97 per kWh(e). Of course, homes with older, less efficient boilers
might pay something closer to $0.12 per kWh(e).

Last winter, my heat pump's seasonal COP was 2.45, so after this most
recent rate increase, my average cost per kWh of heat is 4.4 cents. A
heat pump with a HSPF rating of 9.0 might provide heat for as little
as 3.5 cents. On that basis, the operating cost of a high efficiency
heat pump is roughly one-third that of electric resistance or oil.


I don't have access to the latest numbers, but NSP's heat rate is in
the neighbourhood of 10,000 BTU/kWh. That would place generation
efficiency at about 34 per cent, with additional T&D losses perhaps
pulling that down towards 31 to 32 per cent. My COP of 2.45 brings
that back up to 77 or 78 per cent and a high efficiency heat pump
might kick it to between 90 to 95 per cent. By comparison, my
five-year-old Slant/Fin boiler has an AFUE of 82 per cent.

Bear in mind not all of our electricity is thermal generated -- about
twenty per cent is renewable and this percentage will grow over time
due to provincial mandates. I've opted to purchase 100% green power
(an additional $4.00 per 125 kWh), so my net emissions are
theoretically zero.


I'm not in a position to judge Nova Scotia Power's motives, but I made
a conscious decision to limit my heating oil consumption for several
reasons, not the least of which my fear that a portion of the proceeds
will be used to fund terrorist organizations. Last year, I used a
total of 828 litres of heating oil (220 gallons), the bulk of this
being for the production of DHW. I'm now trying to decide if I will
install a heat pump water heater (a NyleTherm-1), which would cut my
oil consumption by another 500 litres or more; it would also help
minimize my use of the dehumidifier during the summer months (a double
bonus).


This is pure speculation on my part, but I can think of a couple
reasons why our experience here in Canada would be more favourable
than your own. One is that our homes are generally better insulated
and less leaky than our American counterparts -- don't quote me, but I
believe our provincial code requires electrically heated homes to be
insulated to R28 / R60 (walls and ceiling respectively) and R20 / R40
in the case of oil. And because our homes have so little natural
leakage,

heat recovery ventilators are required by law.

What is a heat recovery ventilators, Paul?

The upshot is
 
P

Paul M. Eldridge

Jan 1, 1970
0
Thanks for posting this. Which HP are you referring to? Do you find a
particularr HP brand "better" than the others?

Hi Mike,

You're welcome. I didn't mention the brand because I wasn't sure if
it would be appropriate, but it happens to be Lennox. And I can't
honestly tell you if one make is better than another, because I have
no knowledge upon which to base such an opinion. For what it's worth,
my next-door neighbour has a Trane and loves it. I opted to go with
York for our new building, having had a good experience with three of
their units at our current location and because the local dealer is
top drawer.

Your best bet is to ask friends, neighbours and colleagues for their
recommendations. It's been said many times and I believe it to be
true -- a good dealer is critical to the long-term success of any job.

Cheers,
Paul
 
M

Mike

Jan 1, 1970
0
Paul M. Eldridge said:
That's my suspicion as well. The sample bill I looked at wasn't a
model of clarity either -- mine is pretty straight forward and
provides a full year's worth of consumption data, including the number
of kWh/day used in each billing cycle; a handy feature that allows you
to track your energy use and gage the effectiveness of various
efficiency improvements (and hopefully provide some measure of
positive reinforcement).

Good to learn at least some have helpful bills. Last night I registered on
the BGE website
in an attempt to read indepth information re: my bill. Spent several
minutes but never did
find it. I use the latest version of FoxFire as my browser but very few
sites have problems w/ it, so
I've got to assume the problem is more BGE crap.
Utility investments in new plant and T&D haven't kept pace with
today's growing needs and deregulation has only made matters worse (as
you point out, bulk power transmission is a matter of particular
concern). Back in the "old" days when utilities earned a rate of
return based on their capital expenditures, the criticism was that we
ended up with a "gold plated" system (and there's probably some truth
to that); now with deregulation, we have something that's more akin to
rusted out scrap metal.

Agreed and at some point, not that far away, I believe it's going to
implode.
I'm a free market guy, but a basic vital service such as electricity should
be
regulated. I'll gold plated systems over what we have now any day.. Last
night
I attempted to upload a 38k Tyson Slocum paper but apparently it was
blocked.
I'll see if I can email it to you.

A couple of chuckles - The CEO of TXU energy made $55,000,000.00 in 2005.
I'm sure the TXU utility rate payers love him. I wonder what the CEO made
when it was a regulated utility - $200K? TXU was doing a buff polish job
preparing to sell itself. They present to PUC they want to build 11 coal
fired power plants. Everybody gets their panties in a bunch, then TXU
agrees to ONLY build three coal fired power plants. Of course, they never
planned to build eleven in the first place. Reminds me several years ago
I was on a committee to furnish our new facility and I'm thinking reasonable
numbers when it come to computers. My boss who is chairing the meetings for
our dept kept jacking up the numbers and I'm thinking what's up w/ this guy.
Turns the grandiose numbers were reduced by the bean counters to exactly
what we needed. I suspect that's exactly what TXU did w/ the coal fuels
power plants.
 
P

Paul M. Eldridge

Jan 1, 1970
0
What is a heat recovery ventilators, Paul?

Hi Mike,

A heat recovery ventilator or HVR is a device that brings a constant
flow of fresh air into the home. The key difference between a HVR and
a standard ventilation system is that a HVR transfers heat (or coolth)
between the outgoing and incoming streams by way of a heat exchanger
or transfer core. Small ducts distribute this fresh air to various
rooms throughout the home and a separate set of ducts exhaust stale
air from the kitchen, bathrooms, utility areas, etc.

Our homes are built relatively airtight and without mechanical
ventilation, there can be serious issues with excess humidity, poor
indoor air quality and damaging mould and mildew. This system
addresses this, but greatly reduces the amount of energy that would be
lost in the process. I believe roughly 70 to 80 per cent of the
heat/coolth can be recaptured from the exhaust stream to pre-heat (or
pre-cool) the incoming air.

This is the system I use in my home:

http://www.venmar.ca/Product.aspx?productId=3

Cheers,
Paul
 
M

Mike

Jan 1, 1970
0
Paul M. Eldridge said:
Hi Mike,

You're welcome. I didn't mention the brand because I wasn't sure if
it would be appropriate, but it happens to be Lennox. And I can't
honestly tell you if one make is better than another, because I have
no knowledge upon which to base such an opinion. For what it's worth,
my next-door neighbour has a Trane and loves it. I opted to go with
York for our new building, having had a good experience with three of
their units at our current location and because the local dealer is
top drawer.

Your best bet is to ask friends, neighbours and colleagues for their
recommendations. It's been said many times and I believe it to be
true -- a good dealer is critical to the long-term success of any job.

Cheers,
Paul

Paul, the problem here is I can't find anybody using a current generation
heat pump.
I'll keep looking.
 
P

Paul M. Eldridge

Jan 1, 1970
0
Good to learn at least some have helpful bills. Last night I registered on
the BGE website
in an attempt to read indepth information re: my bill. Spent several
minutes but never did
find it. I use the latest version of FoxFire as my browser but very few
sites have problems w/ it, so
I've got to assume the problem is more BGE crap....

I've seen some pretty rough sites over the years, but this one is in
desperate need of overhaul.
Agreed and at some point, not that far away, I believe it's going to implode.
I'm a free market guy, but a basic vital service such as electricity should
be regulated. I'll gold plated systems over what we have now any day.. Last
night I attempted to upload a 38k Tyson Slocum paper but apparently it was
blocked. I'll see if I can email it to you.

Ok. Thanks. I'll take a look at it when it arrives.

There are parts of downtown Toronto (e.g., Queen St. East) that have a
distribution system that must date back to the 10's or 20's (large,
multi-tier cross bars... heavily loaded and probably running at no
more than 2,200 volts). Frankly, you wouldn't expect to see this type
of hardware in even the poorest of third world countries. And yet,
oddly enough, I lived in a low-density residential neighbourhood in
another part of the city and the distribution system that served my
area was rebuilt from the ground up to run at 27.6 kV. Crazy.
A couple of chuckles - The CEO of TXU energy made $55,000,000.00 in 2005.
I'm sure the TXU utility rate payers love him. I wonder what the CEO made
when it was a regulated utility - $200K? TXU was doing a buff polish job
preparing to sell itself. They present to PUC they want to build 11 coal
fired power plants. Everybody gets their panties in a bunch, then TXU
agrees to ONLY build three coal fired power plants. Of course, they never
planned to build eleven in the first place. Reminds me several years ago
I was on a committee to furnish our new facility and I'm thinking reasonable
numbers when it come to computers. My boss who is chairing the meetings for
our dept kept jacking up the numbers and I'm thinking what's up w/ this guy.
Turns the grandiose numbers were reduced by the bean counters to exactly
what we needed. I suspect that's exactly what TXU did w/ the coal fuels
power plants.

All part of the human dynamic, I suppose. And someday, if I'm lucky,
I hope to discover how it works. :>)

Cheers,
Paul
 
Paul M. Eldridge said:
Our homes are built relatively airtight and without mechanical
ventilation, there can be serious issues with excess humidity, poor
indoor air quality and damaging mould and mildew. This system
addresses this, but greatly reduces the amount of energy that would be
lost in the process. I believe roughly 70 to 80 per cent of the
heat/coolth can be recaptured from the exhaust stream to pre-heat (or
pre-cool) the incoming air.

But that can be a small amount of energy, compared to the cost of heating
an airtight house, on the order of (70-30)15 Btu/h-F = 600 Btu/h. Last
time I looked, Canadian codes required a "mechanical ventilation system,"
which could be a $500+ HRV/ERV, but a kitchen or bathroom exhaust fan
would also satisfy the requirement. In an airtight house, we might turn
it on with a humidistat when the indoor RH rises to 60% in wintertime.

A periodically-reversing fan in an indoor partition wall could turn all
the cracks and crevices in the house walls into efficient bidirectional
air-air heat exchangers, like "Shurcliff's lung," without the need for
an external bellows.

Nick
 
M

Mike

Jan 1, 1970
0
Paul M. Eldridge said:
Hi Mike,

A heat recovery ventilator or HVR is a device that brings a constant
flow of fresh air into the home. The key difference between a HVR and
a standard ventilation system is that a HVR transfers heat (or coolth)
between the outgoing and incoming streams by way of a heat exchanger
or transfer core. Small ducts distribute this fresh air to various
rooms throughout the home and a separate set of ducts exhaust stale
air from the kitchen, bathrooms, utility areas, etc.

Our homes are built relatively airtight and without mechanical
ventilation, there can be serious issues with excess humidity, poor
indoor air quality and damaging mould and mildew. This system
addresses this, but greatly reduces the amount of energy that would be
lost in the process. I believe roughly 70 to 80 per cent of the
heat/coolth can be recaptured from the exhaust stream to pre-heat (or
pre-cool) the incoming air.

This is the system I use in my home:

http://www.venmar.ca/Product.aspx?productId=3

Cheers,
Paul

Thanks Paul I'll check out your link. I also Googled it and got a good
explanation from Popular Science.
The bottom line it appears to me Canada is light years ahead of the US when
it comes to energy conservation.
I've learned a lot between my two original posts. Now I've got to find
some knowledgeable contractors and I'm good to go.
 
S

Steve Spence

Jan 1, 1970
0
Mike asked "> : >>Where are you located?"

I answered him. The indents were screwed up but the threading is correct.
 
M

Mike

Jan 1, 1970
0
Steve Spence said:
Mike asked "> : >>Where are you located?"

I answered him. The indents were screwed up but the threading is correct.
I understood it and want to thank most everybody for posting very useful
information. Now, if I can only find a few good contractors I'll be looking
good.
 
J

jJim McLaughlin

Jan 1, 1970
0
Mike wrote:

SNIPS
This winter we had two straight weeks of temp in the low teens, below zero
and in the teens or twenties during the day.

See, that gobal warming is really coming on strog.

And its all caused by human activity.

Al said so.
 
Top