In message , "Dave Plowman (News)" writes
"Oi IMMate, this conduit is leaking water" "Can't do, its a WA system" "Mebbe so, but ..."
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Maxie! Are you saying warm air systems leak water? Gosh!
In message , IMM writes
Only when you have a part in them
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Cor Maxie!
Search the archive for past posts on this.
If it's that old, budget for replacement with a new system (of whatever type).
MBQ
No experience of owning/running a warm air system myself, but my folks had this type of heating in their bungalow years ago. Warmed the place up ok but made everyone nod off for some reason - and before you ask, no it wasn't on high heat levels and neither was the (gas) boiler leaking gases... I think it may have something to do with air ionisation (+ve charge ?)
Very practical in some ways - no radiators to worry about, lose room/wall space or decorate, but vents in floors/walls/ceilings to aid airflows.
Rog
Warm air heating seems to be the norm in the US whilst wet ?hydronic' heating systems are unusual. I don't know why that should be so. I think that some states have a greater need for AC and de-hum than heating, so the warm air unit was developed almost an afterthought for the existing ducted AC air systems. It's not necessarily a ?bad thing' . The problem is in finding competent servicing for a WA unit in the UK, where even competent technicians for normal boiler systems can be difficult to find. It's unfamiliar so it deters many people, a bit like Citroen hydraulics.
"The air in the house gets very dry, and this was a problem for a couple of contact lens users."
That's caused by the resulting negative pressure. There is a large infiltration (i.e., compared to radiator systems) of outdoor air into the building which, in cold weather, carries little moisture. When this is heated to room temperature, the resulting Rh is very low. Humidifiers are often added to counter this. They are frequently called ?scorched air' systems because it is commonly believed that the air is excessively dried by the heater.
The heat-exchangers are a sheet-metal shroud, with the gas flame on one side and the air stream on the other. Perforated heat-exchangers (CO hazard) are a common service fault.
"under floor heating ducts???..system in the UK (or whatever it was called then) in about 100 AD."
Hypocaust. The air/flue gases didn't enter the occupied space so it was probably more like UFH than WA. Can't get the slaves nowadays.
"The fan coil is detailed at??. (anyone got any experience of these units or manufacture?)"
With other commercial fan-coil units, not this one.
I developed a dislike for them (FCUs). Most were usually Italian made and were in competition with commercial VAV terminals which didn't have a lot inside them in comparison. As a result, the FCUs usually seemed to be made with cheap components. The rated heat or cooling output was usually on top-speed, which was too noisy and blew papers, toupees, small children, etc., around. They were designed to be installed in the occupied space or in a ceiling void. Everything was shoe-horned into a small package and servicing could be difficult. You could get the same functions from an air handling unit (if you had plant space to accommodate it) but without the access problems. FCU Pipe and electrical connections were not often sealed, allowing dust to by-pass the inlet filters and get straight into the fan bearings. The fans often developed irritating squeaks soon after the warranty had expired. The control valves were often mounted external to the casing (ugly). Chilled water valves dripped condensate. The optional-extra control valves supplied by the manufacturers were usually cheaper raise/lower 4-port types, rather than decent 0-10V modulating ones. Some 4-port valves were prone to blockages.
© Copyright 2004. Not to be reproduced in any form without the written permission of the author.In message , Aidan writes
Now go to
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In article , raden writes
[mdt@linuxbox mdt]$ whois snipped-for-privacy@whois.afilias.info [Querying whois.afilias.info] [whois.afilias.info]Domain ID:D295418-LRMS Domain Name:DIYPROJECTS.INFO Created On:13-Sep-2001 06:07:50 UTC Last Updated On:13-Sep-2004 15:42:22 UTC Expiration Date:13-Sep-2005 06:07:50 UTC Sponsoring Registrar:R139-LRMS Status:ACTIVE Status:OK Registrant ID:C5755079-LRMS Registrant Name:The Hostmaster Registrant Organization:Web-S-Sense Pty. Ltd. Registrant Street1:P.O. Box 110 Registrant City:Surrey Downs Registrant State/Province:SA Registrant Postal Code:5126 Registrant Country:AU Registrant Phone:+61.0408827991 Registrant Email: snipped-for-privacy@web-s-sense.com
[mdt@linuxbox mdt]$ whois snipped-for-privacy@whois.opensrs.net [Querying whois.opensrs.net] [whois.opensrs.net] Registrant: Web-S-Sense Pty. Ltd. P.O. Box 110 Surrey Downs, SA 5126 AUDomain name: WEB-S-SENSE.COM
Administrative Contact: Hostmaster, The snipped-for-privacy@web-s-sense.com P.O. Box 110 Surrey Downs, SA 5126 AU +61.0408827991 Technical Contact: Hostmaster, The snipped-for-privacy@web-s-sense.com P.O. Box 110 Surrey Downs, SA 5126 AU +61.0408827991
[mdt@linuxbox mdt]$ whois snipped-for-privacy@whois.abuse.net [Querying whois.abuse.net] [whois.abuse.net] snipped-for-privacy@web-s-sense.info (default, no info)Looks like diyprojects.info is the same organisation as its' registrar. Try emailing snipped-for-privacy@web-s-sense.info with a copy to postmaster@web-s- sense.info.
If they are unresponsive, complain to the upstream provider and owner of the IP block: snipped-for-privacy@theplanet.com.
Impressed, eh? I thought the copyright protection notice "© Copyright 2004" was a good idea. So I copied it from Andy Hall's post.
You're welcome. There's no charge.
.andy
To email, substitute .nospam with .gl
Forced air is the norm and they understand and do it far betetr than what we do.
The same reson we stadardised on rads. No real reason. Although using the same distribution medium to heat and cool makes sense.
No. Waerm air was used beofiore coold air. In states were cooling is not required they still go for forced air.
It is brilliant when done properly, by far the best heating system. It can heat/cool/dehumidify/dehumidify/supply fresh air, Get your rads to do all that.
J&S will service it, and also the gas board will too. I started off on warm air, and later went over to wet systems. Wet systems are now over complex for what they do: heat rads and water.
A sinmple humififioer can be installed. A spinner in the duct.
Forced air can be positive or negative pressure depending on design.
Positive pressure systems tend to be prefered as they elimiante any draughts that negative pressurev would cause.
Which it isn't.
Heat exchangers do not hole regularly.
It also heated the walls too. And the thermal mass kept the temperature stable.
The loft is an ideal place for an air hander. Some small sizes are being made.
Get what you pay for.
Not unless you've got a deionized water supply. Steam or ultrasonic.
Yes it can, but I think that the design of most US domestic WA systems results in a negative internal pressure & resulting air & dust infiltration.
They can perforate. More recent ones allegedly have thinner metal (cheaper?) and are more prone to it. The sheet metal heat exchangers are the cheapest way of getting the heat into the air, but I don't like the idea. I'd think you'd be almost certain to get flue-gas condensation & corrosion problems. I haven't worked on them & won't pontificate. You could get something similar (probably still can) for commercial AHUs, but a proper finned tube heater battery would be my preferred method of heating every time. The controls & freeze protection then gets more complicated & expensive.
Generally. Sometimes you don't get what you paid for. If you're buying a FCU for the first time, you'd probably find you hadn't got desirable features (reliability, quietness at the rated heat output) that you'd thought you had paid for. As with most things.
heat/cool/dehumidify/dehumidify/supply fresh air, Get your rads to do all that.
Nah! The problem with air is that, as a medium for shifting heat (or cold) around, it is 1,000 times less dense than water and it's specific heat capacity (kJ/kg K) is about a fifth that of water. The result is that you'd need a much bigger pair of ducts to move the amount of heat you could shift through a pair of water F&R pipes. With air, you'll also get associated problems with noise, draughts and blowing dust around.
The problem with rad systems is that they don't accommodate peoples' need to breathe fresh air; most systems rely on the infiltration of air (and dust) through openings.
Best system; passive heating or cooling (rads, UFH, chilled beams, chilled ceilings) to move the heat loads PLUS variable speed supply and extract ventilation to maintain a positive pressure minimizing the ingress of dust. Air volume increases during occupied periods to supply tempered, filtered air. If cooling devices are used, then the CHW flow temp must be kept above the room dew-point. It costs a fortune, but I'm only designing this, not paying for it. It is done elsewhere. It won't cope with high heat loads, so you'd be stuck with conventional AC cooling.
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US air heating and cooling systems use what I would describe as a "dampcloth" humidifier system. Tap water is dripped onto a matrix, which air passes over. This is changed a few times a year, when it grows too many algae. The system is normally pressure neutral. ie the fan sucks air from the boiler room local ambient, filters and heats it before blowing it around the house within the ducting. There is very, very little dust circulated. Some houses have an attic mounted ceiling return duct, which keeps air circulating under all circumstances.(Ceiling flow can sometimes be reversed to give better results from the A/C in summer.) Many houses don't have this, they rely on the bloody great gap at the bottom of the door. The filters are extremely good, but obviously need changing on a regular basis. Heat exchanger perforation does not seem to be a regular occurrence for the average household. Dehumidifying can be achieved with the air conditioning unit, but this tends not to be used in winter. US houses IME have very poor draught sealing, so there is quite a lot of uncontrolled air changing taking place under normal circumstances. We would regard the efficiency of the house insulation as very poor, but for an up market garden shed, this is what you get!
Regards Capitol
In message , Aidan writes
Adian, unless you specifically want to retain it, the need for disclaimers has now gone
As long as the water is descaled it works fine.
No. Most is positive to overcome any draughts.
I have and holes in them is rare. They are Stainless steel.
The only time I would go for that is when the boioer also heat the DHW, which would be most times.
That is not a problem. There are smaller tubed duct systems around using high velocity air. They are not noisy.
Old wives tales. Not if done properly with electrostatic air filters, and correctly sites and designed equipment. Draughts? If the air is heat high enough, no draughts.
Exactly.
May as well as upgrade the duct sizes and make the whole system an air system.
Air heating is very common. It is the choice in commercial buildings and cars. You may find that most people are heated by air.
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