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 "Enough energy lands on every section/lot in the country to provide many times the energy needs of a typical home."

DSHH Q&A - FAQ

Installation-Warranty 

Builders should be Master Builder or certified Builders and include a comprehensive warranty for all facets of installation.
Parts Warranty

 

Factory warranty applies to all parts such as control valves, pumps, solar collectors, and pipes. Copies available on request.

 

How does DSHH Underfloor Heating

work?

 

In Layman's Terms

1. See diagram : For this to work the house MUST be a thermally efficient home and be EEH approved for energy efficient design, to work properly. The key element in the DSHH system is the custom designed digital controller with a large LCD display.  It uses over 6 thermal sensors, and controls various control valves and pumps to distribute heat as required.

 

2. Large evacuated “U” tube solar collectors collect huge quantities of heat during sunny days, especially over the summer.  These types of E/T solar collectors also work well in sub-zero temperatures.

 

3.The heat is controlled by the DSHH custom digital controller, and as required is targeted  at:

a. hot water cylinder,

b. the slab floor and

c. a Solar heat containment storage area under the slab. 

Thus: if not required to heat the hot water (Opt) or house, the excess heat is dumped (Saved/stored) into a huge in-ground thermal mass heat core storage area. The heat core is located in the ground itself, and comprises the whole floor area of the slab, inside an insulated  wall min. 1M high, underneath and insulated from the Slab. This in effect  encompasses the “whole-house” foundation under the slab.

 

4. Eventually this heat containment area becomes saturated with heat at the top and through conduction, permeates downwards filling the heat containment area and below. This limited speed of conduction is what makes the system long lasting. A long time to thermally charge up and a long time to extract the heat.

 5. As required in winter, warm water is automatically extracted from the collectors or heat core as required and circulated through a series of pipes laid in the concrete slab (floors) of the rooms. These pipes form a continuous loop and act to create a large warm surface that will warm the room to a comfortable background temperature. In summer all heat generated is dumped into the heat core, dramatically rising its temperature, and providing for long term storage.

6. Concrete slab floor temperature is limited to only a few degrees above thermostat set point temperature, with the floor temperature nominally limited to “Warm”. The concrete slab is also thermal mass and releases the heat slowly over long periods of time.

 

7.Even in winter the U Tube evacuated tube solar collector system generates significant heat on cold sunny days. The vacuum tubes act much like a Thermos type bottle; it keeps the solar collector isolated from most of the cold. A Solar hot water system can be integrated into the package as can a Wetback or fireplace boiler for backup.

 

8. 1:1 coverage is calibrated: Each m2 of home to be warmed, requires ~1m3 of standard earth, hardfill, hard pan or rock for thermal storage in most of the N Island and slightly more in the South Island.

 

Expectations: In optimal locations in the North Island, excluding the plateau, design is for a standard whole-house background temp of 18c for most of the winter, and 18c for 75% of the winter in Southland and the plateau areas. These figures will vary based on house design, earth, thermal mass, temperature set point, as well as summer and winter sunshine hours. The system will inject solar heat even in winter under freezing conditions outside. It is anticipated the system will improve over time as the heat core storage increases in thermal energy.

Can the DSHH underfloor heating be installed in any new building?

 

For optimal service it can be installed in any ‘EEH’ approved thermally efficient design with a slab floor.  Note it takes a full summer to get a nominal heat charge in the thermal heat-core, it can take 2-4 years to fully ‘charge’ the heat core depending upon location and circumstances.

What about  backup or Wetback/Fireplace boiler?

The DSHH has an option to integrate a wetback or some other boiler. Like the Solar heat, the Digital controller will first heat the Hot Water Cylinder, then the house, then dump excess heat into the core to a maximum of 80c residual.

Will DSHH underfloor   heating affect timber  flooring?

The DSHH Under-slab heating will not affect wood, tile or laminate flooring due to the low slab temperature (Max 25-28c typical) which is less than summer heat temperatures, however; be careful with natural wood flooring where you must ensure the moisture content is low in the timber during installation to prevent shrinkage. Also be aware, timber flooring acts as a partial insulator, reducing the effectiveness of the warm slab.

Will the DSHH underfloor heating work through a carpet?

Yes but not very well for the same reason as above. The carpet will act as an insulator; try to avoid thick carpets and underlays in areas you want the heat to permeate. Obviously the system’s efficiency improves without the insulating effects of a carpet system; this can be mitigated in some areas such as bedrooms where less heating is preferred, or carpeting is localised.

Will the rooms be warm enough?

The DSHH system was designed from the beginning to be a background heat, to stop the house from dropping below world standard recommendations of 16.5c, where mould and mildew spores start to fester. It's optimal winter operational temp is 18-20c with emphasis on preventing the serviced portion of the home to drop below 18c.

Provided that the room meets the minimum EEH insulation requirements, plus the system is designed and installed correctly, and reasonable care is given to ensuring continued thermal efficiencies in the home, it will operate as per the ‘expectations’ above.

Remember this is not a rapid heat, but is designed to provide a continuous background heat over long periods. The engineering is designed to provide ~18c for most of the winter. You may want some locations warmer in winter or cooler in summer, thus it is a good idea to have some sort of supplementary heat/cooling.

 

Can the DSHH underfloor heating be installed in timber floors? Not advised, but yes it can by using heat spreader plates under the floor. NOTE: It is not very efficient due to the insulating factors of the timber, the relatively low heat of the operating system, and is not fully tested at this point, nor recommended.

 

Will the DSHH floor get hot and what about area zoning ?

No, generally underfloor heating has a low return temperature and is designed and limited to few degrees above the thermostat set-point temperature: typically max 25-28c. This eliminates stress in the concrete and reduces the time it takes to get up to temperature from cold. The DSHH heating system is designed as a background heat.

Some Areas can optionally be Zone controlled. It is wise to advise these areas in advance of the design phase. During the design phase we focus the initial warmth in areas such as bathrooms and living areas, with less heat focused on sleeping areas and hallways.

 

Can it be installed as a 2 stage installation? Yes, in order to save on up front capital costs, it can be installed in 2 separate stages. It imperative the heat core be installed properly, and that the heat exchange pipes be installed at build time. Also pipes need to run into the roof along with temperature sensor wires for future use. This will allow the more expensive Solar collection system and control system to installed later, perhaps when funds allow.

Note: If you are considering a solar hot water system, we would highly recommend  you purchase the optional DSHH solar hot water materials package. The reason is it will be compatible with the future DSHH system and this system will not cost you any more than a decent higher quality solar HW systems. We can supply a special solar controller that will allow excess heat to be dumped into the heat core or slab as required. The EEH  high tech Solar Hot Water system will actually heat most hot water tanks/cylinders to their design temperatures by late lunch time, and then the system goes into stasis as it tried to handle the excess heat. The DSHH controller can direct the excess heat to the core or slab pipes, effectively using your excess heat. This is not a huge amount of energy but can help offset a chilled slab in winter.

 

Can I convert my existing expensive to operate under floor heating to this? The easy answer is a qualified yes.

Your underfloor heating is designed as a "Demand" heat system, whereas the DSHH is designed as a background warmth system. This means the heat is not designed to make the floor hot, in fact we limit the slab temperature to 29c so as not to heat it in an extravagant fashion.

If you have radiators only they will not be of much use as they are concentrated heat and wee deal with energy not necessarily high temperature.

The Solar package could be sized to heat your home for much of the year if you don't have the massive thermal heat core of the DSHH, this means 2 things:

  1. Your heat will be less reliable in cloudy conditions. On the + side, it will still offset a large part of your heating costs.
  2. You will need some sort of backup. We offer optional wetback integration as well as Hot Water Heat Pumps, which can do double duty as lower cost hot water backup as well as heating backup. Ask us if you are not clear.
Can I use an underfloor heating system as a cooling or A/C system? We don’t recommend it as cool air tends to stratify close to the floor, unlike heat which tends to rise and mix. Install a quality DC Inverter Heat Pump for your best cooling, in fact we recommend one for backup, summer cooling, or zoned heating requirements. Remember the size of the heat pump can be considerably smaller with an EEH home, be sure heating contractor is aware of this.

 

DSHH does offer an optional 7.7, and 8.8 kW hot water heat pump with a COP of 3.5, but this is not designed to cool.

 

BENEFITS OF THE EEH DSHH UNDERFLOOR HEATING    

 There are a number of features and benefits that occur from almost free underfloor Solar Heating.

 ü Space & Economics

No huge ongoing and ever increasing expenses for energy in heating for as long as you live in the home and the system operates normally. Every square metre of your home can be fully utilized, and no ducts.

ü Eco-Friendly, Carbon Neutral

Virtually Zero carbon emissions during the heating operation of this system after the first year. As this reduces the need for expensive oil imports, it becomes very close to carbon neutral.

If a PV (Photovoltaic) power station were added, the DSHH system would easily become carbon neutral, and if increased substantially the whole house could be designed to be energy carbon positive.

 ü Hygiene & Health

There are huge positive health implications. For example: No dust is generated or circulated. The heating will help asthma sufferers as it reduces dust mites at floor level and can virtually eliminate toxic mould and mildew. The NZ government advises that if you keep the house above 16.5c, mould and mildew is unlikely to grow in normal living areas in your home. No mould, no invisible allergenic spores, & warm home = improved health..

 ü Comfort & Intrinsic Happiness

It is pure luxury in winter to come home to a warm home. The DSHH provides comfortable background levels.

 ü Cost effective & Savings

Once installed, the DSHH will typically provide a heating energy saving, from 50% to 100% over your typical NZ heating costs. The improvement when compared to bog-standard, poorly insulated existing NZ home can be in the hundreds of percent. Actual results will vary and can be optimised.

 ü Super Quiet

Compared to forced air or radiator systems, there is no noise, no annoying air noises or ticking as pipes expand in floor voids. The pump is typically a 47watt unit that is virtually silent when running.

 ü 2nd Floor

The DSHH is designed to heat one floor which is the equivalent of the SqM of the heat-store area. A 2nd floor will benefit from the DSHH system through conduction and convection. We can also increase the size of the heat core and install a floating concrete floor above to achieve the best results. Remember the core is matched to the house footprint size, location, and circumstances of your build thus expect 2nf floor and performance losses accordingly.

ü Backup Heat

Integrated Wetback or other boiler heat source is simple, and only requires a few extra components as long as the pipes are in place. A DC Inverter heat pump is also a good investment as it provides summer Air Conditioning as well as back up heat in winter. Note: A heat pump should be sized according to heat loss not just as per house SqM: thus the actual size/cost of a heat pump required is much lower in an EEH home.

 ü Ease of control

The DSHH is fully automated for day to day running. Set and forget with periodical checks to ensure all is well.

 

 

Wonderful background warmth

 
 

If you have any other question we could answer, call us on 09-815-6664 or, click on the "Contact us" link  to send us a message.

Notes:

  • Most pictures are of actual homes, customized for each customer, and therefore may show features not included in the base offering, but available on request as an option
  • Purchase Large  168 page, high quality, full colour, Catalogue available containing all current models. $79 including postage. Payment by EFT, cheque or Credit card (via PayPal): Please contact us for details
  • Models are also available on interactive CD for $10 including P&P, and include high resolution pictures: Please contact us for details
  • All models can be ordered with Garages
  • All Models can be customised
  • All models can be optimised by the use of basements, a low cost way to enlarge any home

Please contact us for more information

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Email: info at dshh dot info