[Cameron]

Hi

Trying to decide how to heat my house - currently building an extension - turning my 2 bed bungalow into a 5 bed house + a few other rooms

I would like a system that works well, efficient and relatively cheap to install.

The options as I see it are

Radiators (Victorian)
- MUST be inefficient having to heat the water that hot to try any get a bit of convection going?
- however current system uses Rads
- would be the path of least resistance

Wet under floor heating (80's)
- Must be more efficient than Rads - lots of pipes
- would my existing boiler (Valient Combi) work effectively with it (I assume it was not designed to produce lots of low temperature water)
- Its slow to respond to temperature changes?
- Any places I can get further installation info ?
- Could I use the return water (lower temp) from the current Rad system to heat the extension (at least until I can mod the rest of the house)
- Using relatively low temperature heat _ could I supplement the heat source at a later date i.e. solar, wind, waste water recovery etc?

Hot air system (21st Century)
- What I can gather from my cousin who uses these systems to heat swimming pool buildings _ is that they are stunningly fast to respond?
- have a void under my bungalow and extension so could install ducting
- Should be efficent because of the lower temperature?
- What about condensation / humidity?
- Could I use the return water (lower temp) from the current Rad system to heat the extension (at least until I can mod the rest of the house)
- Using relatively low temperature heat _ could I supplement the heat source at a later date i.e. solar, wind, waste water recovery, wife running on a tread mill, etc?

Thank you

Cameron

On 23-Sep-2005, Cameron wrote:

- MUST be inefficient having to heat the water that hot to try any get
a bit of convection going?

Modern water heating systems use pumps, not convection. A pump
for a five bedroom, two story house is about the size of a fist.
The modern radiators are fairly efficient - not the big blobs of
iron used in the old days. While the system takes a bit of time
to get going, the water retains the heat and the pump continues
to distribute the heat after the burner has shut down.

solar, wind, waste water recovery etc?

Solar, yes. Wind, no - the energy density in wind isn't sufficient
to generate heat for a house. Ditto waste water heat recovery -
how much hot water are you going to flush down the drain?
While waste heat recovery is a good plan, you have to supplement
that with a very well insulated house to make it worthwhile.

- Could I use the return water (lower temp) from the current Rad system
to heat the extension (at least until I can mod the rest of the house)

Build-it-yourself heat exchanger? Why not do the whole thing correctly
from the get go?

Mike

"Cameron" wrote in message
...

Hi

Trying to decide how to heat my house - currently building an extension
- turning my 2 bed bungalow into a 5 bed house + a few other rooms

I would like a system that works well, efficient and relatively cheap
to install.



Efficient is more expensive, relative cheap may not be as efficient.

There are a ton of other questions that need to be asked and the manual
calculation need to be done for proper sizing and air flow.

Call licensed contractors and ask them for some ideas and bids on their
designs. People in your area probably all ready know the systems to stay
away from.

"Cameron" wrote in message

I would like a system that works well, efficient and relatively cheap
to install.

There are none that meet all three of your criteria


Radiators (Victorian)
- MUST be inefficient having to heat the water that hot to try any get
a bit of convection going?
- however current system uses Rads
- would be the path of least resistance

Myuch more efficient than you think. The only negative is style. People
think they are old loking and take up a lot of space, but they are one of
the best methods of heating a room. Why convection? That is what pumps are
for.



Wet under floor heating (80's)
- Must be more efficient than Rads - lots of pipes

Not really. In a retrofit, it may be much less. Slow reaction times too.


- would my existing boiler (Valient Combi) work effectively with it (I
assume it was not designed to produce lots of low temperature water)

Considering the size change, a new boiler is probably needed.


- Its slow to respond to temperature changes?

It is in your house so you can tell me.


- Any places I can get further installation info ?

Trande publications, web sites.

- Could I use the return water (lower temp) from the current Rad system
to heat the extension (at least until I can mod the rest of the house)

Sort of. As the water passes through each radiator it is giving off some of
its heat energy. If you extend the run to other rooms, it will give off
more of it and has to be reheated that much more to start the cycle. The
boiler capacity will determine it is is enough to handle the entire house,
but I doubt it. Heat output is finite. Depending on the load and the
capacity of the boiler, it may not sufficiently heat hte house come cold
weather. Load calculations must be done.

- Using relatively low temperature heat _ could I supplement the heat
source at a later date i.e. solar, wind, waste water recovery etc?

Sure, you can do that at any time.


Hot air system (21st Century)
- What I can gather from my cousin who uses these systems to heat
swimming pool buildings _ is that they are stunningly fast to respond?

Yes. They require duct work that may or may not be easy to install. Some
people complain the are drafty. They tend to be a dryer h eat and need
humidifcation.



- have a void under my bungalow and extension so could install ducting

Void? Good place for h eat loss also, but it may be possible to do it.
Insulation needed, of course.


- Should be efficent because of the lower temperature?

I'm not sure what you mean by this. Temperature does not assure efficiency.

Sorry, Ed, but you'll confuse him with the bit about forced-air being
dryer. Not so. Whether air is heated at furnace heat-exchanger, or at
skin of radiator, a given temp rise will result in precisely the same
change of relative humidity. Humidification with forced-air is a
piece-of-cake.

Water leakage from system is another story, and should not be fixed.

HTH,
J

Trying to decide how to heat my house - currently building an extension
- turning my 2 bed bungalow into a 5 bed house + a few other rooms

I would like a system that works well, efficient and relatively cheap
to install.

The options as I see it are

Radiators (Victorian)
- MUST be inefficient having to heat the water that hot to try any get
a bit of convection going?


I can't think of any reason why this should be any more inneficient
than anything else. Where is you expect heat to be lost?

wrote in message
Sorry, Ed, but you'll confuse him with the bit about forced-air being
dryer. Not so. Whether air is heated at furnace heat-exchanger, or at
skin of radiator, a given temp rise will result in precisely the same
change of relative humidity. Humidification with forced-air is a
piece-of-cake.

While you are scientifically correct. my nasal passages tell me different.
At least that is my experience with two houses I lived in with forced hot
air heat. Maybe older, less efficient equipment was a factor.

Radiators provide comfort at lower air temperatures than forced air
systems becaise they warm your body directly by radiation (hence the
name) rather than having to heat the air first. They can be very
efficient. Your boiler has a lot to do with that too. Look up the
Hydrotherm Hydropulse boiler. It may well be that your old boiler was
oversized, you may be able to use it over. Get a heating contractor to
do a load calculation to find out. Where you are (climate) helps
determine what system is best for you.

Stretch

How well have you done the insulation?


Cameron wrote:


Hi

Trying to decide how to heat my house - currently building an
extension - turning my 2 bed bungalow into a 5 bed house + a few
other rooms

I would like a system that works well, efficient and relatively cheap
to install.

The options as I see it are

Radiators (Victorian)
- MUST be inefficient having to heat the water that hot to try any get
a bit of convection going?
- however current system uses Rads
- would be the path of least resistance

Wet under floor heating (80's)
- Must be more efficient than Rads - lots of pipes
- would my existing boiler (Valient Combi) work effectively with it (I
assume it was not designed to produce lots of low temperature water)
- Its slow to respond to temperature changes?
- Any places I can get further installation info ?
- Could I use the return water (lower temp) from the current Rad
system to heat the extension (at least until I can mod the rest of
the house) - Using relatively low temperature heat _ could I
supplement the heat source at a later date i.e. solar, wind, waste
water recovery etc?

Hot air system (21st Century)
- What I can gather from my cousin who uses these systems to heat
swimming pool buildings _ is that they are stunningly fast to respond?

- have a void under my bungalow and extension so could install ducting

- Should be efficent because of the lower temperature?
- What about condensation / humidity?
- Could I use the return water (lower temp) from the current Rad
system to heat the extension (at least until I can mod the rest of
the house) - Using relatively low temperature heat _ could I
supplement the heat source at a later date i.e. solar, wind, waste
water recovery, wife running on a tread mill, etc?

Thank you

Cameron

[Cameron]

Thankyou all!

Let me try and explain some of my "mad proffesor" logic - rightly or wrongly

Efficiency
- the target temp is a room air temp of 19oC - 21oC
- i'd assumed (ASS of U and Me) that the more of the waste heat (the return boiler tempurature) used, the more efficient the boiler?

Boiler Size
Put it in myself 6 years ago - 95btu combi - way obversized for heating a 2 bed bungalow - but I wanted to fill a bath!
Other than the quality of the thing, I have no complaints - a combi fan!

Insulation
200mm Loft - no walll - new extension will be to building regs

"Hydrotherm Hydropulse boiler" wow! sounds like some body enema device!


Can I "please" rephrase my question

What would you do?

"Cameron" wrote in message
Efficiency
- the target temp is a room air temp of 19oC - 21oC
- i'd assumed (ASS of U and Me) that the more of the waste heat (the
return boiler tempurature) used, the more efficient the boiler?

Heat will alway seek out the cooler areas and try to reach equilibrium. The
higher the differential, the faster the heat will move. The air will absorb
heat from the radiators and once the air reaches the temperature set on the
thermostat, the circulator turns off. Any heat put into the water is going
to be given up in the house. It may be in the feed pipes or return pipes,
it may be in the room that you want to heat or another room, but all the
heat generated and put to the water will be in the house. Essentially, it
is 100% efficient from the water.

While heating the water, some energy is lost up the chimney. If 20% goes up
the dhimney, the heater is 80% efficient. With carbon based fuel, products
of combustion myst be vented up the chimney so no heater will ever be 100%
efficient.



Boiler Size
Put it in myself 6 years ago - 95btu combi - way obversized for heating
a 2 bed bungalow - but I wanted to fill a bath!
Other than the quality of the thing, I have no complaints - a combi
fan!

Oversized will cycle shorter time. May be some efficiency loss from
constant starting. but toher can better answer that.


Insulation
200mm Loft - no walll - new extension will be to building regs

Look into putting some in the walls. Major savings to be had.


"Hydrotherm Hydropulse boiler" wow! sounds like some body enema
device!


Can I "please" rephrase my question

What would you do?

About what? Oh, heating hte new addition? I'd add some cast iron
baseboard.

have another glass of wine.

http://www.minibite.com/america/malone.htm

[Cameron]

Good idea!