RE: Anyone heard of Keith Harrison Electrical ?

["Neil Ball" <neilball@xxxxxxxxxxxxxxx>]

With electric UFH you must use a floor stat to prevent potential
damage to
the floor so yes, there will be one per room. These can then be wired in
series with a room stat or other control device (timeclock, Comfort with
room sensor or stat for example) so HA control should not any more
difficult
than with any other heating system. You could run the system without any
room stat control and simply adjust the heating to the room via the
individual floor stats. As long as you star wire the supplies back to Node
0
then you can change the zoning and control arrangements as you see fit at
any time.



The varying of voltage to provide modulated output will give a smoother
response than simple thermostatic switching and can be more energy
efficient. However you can replicate this to some extent by using
time-proportioning control based on the room temp if Comfort allows simple
logic programming. This method means you vary the on-off cycle depending on
the load. At full load the system is simply on. As you approach setpoint
you
begin to switch the load off for increasing amounts of time until it is
fully off if you exceed setpoint. A bit of trial and error with the timing
and scale (how close to setpoint this feature kicks in) will give you a
similar effect to the fully modulated control offered by the flash system.
As the floor has an amount of thermal inertia it should not need to be
switched very quickly so standard relays should still work well. If the
time
period was very quick then solid state relays would be the better option.



Where you may have problems is if the supplier/manufacturer of the UFH
system only has one particular floor stat option which combines floor
protection with time control and air temp control in a flashy digital stat.
In this case you have two options - buy the complete package and bypass the
control options you don't need. Pros - no warranty issues with the UFH
supplier and no different to their standard installs so they do not need to
know that it is to be controlled by a separate system, easy to return to
"standard" control if you move and take the HA with you. Cons -
more
expensive. Otherwise why not go back to the supplier and ask if they can
give you the specs for a basic floor stat option that you could source and
supply instead and then continue as before.



Neil B.



_____

From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
Gareth Cook
Sent: 20 February 2006 12:12
To: ukha_d@xxxxxxx
Subject: [ukha_d] Anyone heard of Keith Harrison Electrical ?



Been speaking to the Underfloor heating company - and they've mentioned
they pass the one or two HA queries they get over to them...

It apprears the thermostats they sell vary the voltage to the floor, and
have a thermostats that measured floor temperature (underneath the wood)
to ensure the floor doesnt go above 27 degrees. They say there is a
possible module you can add on but not sold in this country.

With this system, you have to have a thermostat PER room - and that means
no central control. Also, if the voltage is variable, then I cant just
hang it off a CBUS relay.

G.

Gareth Cook
Tools and Process Architect
IBM SWG Sales - Lotus Park, Staines, TW18 3AG
Office: +44 (0)1784 445166 - Mobile: +44 (0)7980 445166
AIM Chat : TheBoyG - MSN Chat : chat@xxxxxxx
email: g@xxxxxxx









SPONSORED LINKS


Home
<http://groups.yahoo.com/gads?t=ms&k=Home+repair+improvement&w1=Home+repair+
improvement&w2=Computer+stuff&w3=High&w4=Improvement&c=4&s=76&.sig=TcERUCDPQ
cJLbg9mtvQGJQ>  repair improvement

Computer
<http://groups.yahoo.com/gads?t=ms&k=Computer+stuff&w1=Home+repair+improveme
nt&w2=Computer+stuff&w3=High&w4=Improvement&c=4&s=76&.sig=plS9-eUUfaBXyLVFT8
7AJg>  stuff

High
<http://groups.yahoo.com/gads?t=ms&k=High&w1=Home+repair+improvement&w2=Comp
uter+stuff&w3=High&w4=Improvement&c=4&s=76&.sig=b5d547gPx7eFWNGqXQCl7A>


Improvement
<http://groups.yahoo.com/gads?t=ms&k=Improvement&w1=Home+repair+improvement&;
w2=Computer+stuff&w3=High&w4=Improvement&c=4&s=76&.sig=O6pw_oratTOwep2G_91fI
Q>







_____

YAHOO! GROUPS LINKS



*	 Visit your group "ukha_d <http://groups.yahoo.com/group/ukha_d>
"
on the web.

*	 To unsubscribe from this group, send an email to:
ukha_d-unsubscribe@xxxxxxx
<mailto:ukha_d-unsubscribe@xxxxxxx?subject=Unsubscribe>

*	 Your use of Yahoo! Groups is subject to the Yahoo!
<http://docs.yahoo.com/info/terms/>
 Terms of Service.



_____



[Non-text portions of this message have been removed]