"Ed Sirett" wrote in message
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On Sun, 20 Nov 2005 13:43:44 +0000, Doctor Drivel wrote:
"Ed Sirett" wrote in message
news
On Wed, 16 Nov 2005 21:07:26 +0000, gastec wrote:
Which do you feel is better,,Warm Air or Wet Systems????
IMHO wet systems especially underfloor wet systems would have to be
considered better in many respects except for warm up time.
Can you highlight the respects please.
As below. I will make my representations on this matter once clearly.
I have no intention of getting into a ding dong thread.
Distributions of smells.
Not a problem with forced air if designed and installed properly.
By their very nature an odour (or aroma) in one room will find it is
drawn back to the unit (remember the regs state there has to be an
explicitly installed return path). This is inevitably going to be
distributed into all the rooms with open registers soon afterwards.
You really don't know do you. Carbon filters can be fitted if smells are a
problem. With fresh air systems, that always intake a percentage of fresh
air this is rarely a problem. With fresh air forced air, the air quality is
far better than a locked up rad or UFH system.
Dust, (even with electrostatics).
Nonsense.
Not nonsense but I concede I may be over stating the case.
It is nonesense.
Noise levels.
More nonense. no more than any fan flued boiler.
The noise of the boiler is only at
the boiler with a ducted system the
noise travels in the duct to the rooms.
Nonsense if designed and installed properly. How many houses are plagued
with pumps and water noises in a wet system. Of course..if it is designed
and installed properly then problem...as with forced air.
Although I concede that wet
systems have there own sources of noise
(creaking pipes, rads, water
noises, pump noises and TRV troubles).
Draught levels.
Nonsense again. A positive pressure system eliminates draughts.
Not draughts from outside, silly. Draughts caused by the fact that air is
being forced - if it isn't then the system isn't working!
Nonsense. Moving air does not cause draughts. If it is of the correct temp
then no draught feel. Once again, design and fit right.
Difficulty is finding qualified people to service them.
Same gas controls as on boilers.
Indeed so, BUT.
Most fitters and/or installing businesses
are not prepared to pay several
hundred quid to acquire a qualification
(DAH1) that is unlikely to be needed.
In areas where forced air is common service people are not difficult to come
by. Have an air handling unit with copper heater battery and no corgi or BBA
anywhere insight, as it is remote from the boiler..
Bulky ducting.
Designed and installed right you don't see them. Not an issue.
They take up space that simply isn't
available in the majority of UK
housing. Above all other considerations
this is the show stopper.
I said: "Designed and installed right you don't see them". This is self
explanatory. Design the house for it and they shine - as in the USA, who
the experts at this game. I have seen forced air retrofitted in 1930s
houses. The ducts under the ground floors with a air handler under the
stairs, and a air hander suspended in the loft All totally inconspicuous.
Fresh air and heat recovery too. Hot summers days? 100% air from outside
cooling the place with air movement in every room.
Give me one of these over rads or UFH anyday. BTW, the trendy thing in new
house in heat recovery and vent. Which is a downside forced air system.
I have rads. I was considering having a small air handing unit in the loft
doing the upper rooms and a large grill in the hallway. Then only a few
rads left in some downstairs rooms. Then no stupid draught causing trickle
vents on windows.
Don't go on old wives tales and the cheap system you saw in the council
estate. Even the council estates can be greatly improved by installing a
modern modulating burner and fan unit. They are a world away from the old
British tat.
More info: Suggested books. Manual D
The books are published by the Air Conditioning Contractors of America. The
books may be ordered via their web site or email. They are very readable
and anyone with an average background maths can understand them.
Web site:
http://www.acca.org/
Book 1. Residential Duct Systems Manual D
Design a residential duct system in a fraction of the time with the
streamlined duct sizing procedure in the new edition of Manual D. You can
apply the new procedure to constant volume systems and zoned, variable air
volume systems, over the full range of duct construction materials. The new
Manual D also includes the most comprehensive equivalent length data ever
published. (298 pages)
Topics include:
· Residential air-side equipment
· Basic principles of multi-speed and variable speed blowers, pressure loss,
operating point, and duct sizing calculations
· Examples of duct sizing calculations - constant volume systems, flexible
duct, junction box systems, multiple zone VAV systems, two story VAV
systems, and system retrofits with VAV dampers
· How duct leakage affects indoor air quality and the combined performance
of the envelope equipment system
· Duct losses--conductive losses and leakage losses
· Noise control
Catalog ID: 29-D
Book 2. Residential Load Calculation Manual J Seventh Edition
With step-by-step examples, Manual J shows you how to calculate the heating
and cooling loads of single-family detached homes, mobile homes, condos,
town houses and apartment buildings. It's crammed with 38 figures and 16
tables to cover all standard residential construction methods. (126 pages)
Topics include:
· Basic principles of heat transfer, R-values, U-values, and heat transfer
multipliers
· A step-by-step example of a single-zone, single-family, detached
calculation for a whole house and room-by-room
· Sample calculations for multi-zone variable-air-volume systems and
multi-zone split-coil systems
· Mobile home load calculations
· An optional procedure for making leakage area and infiltration CFM
calculations on a component-by-component basis (Berkley Model)
· Review of the methods used to estimate annual energy consumption
and operating cost
Catalog ID: 33-J