MINI ELECTRIC TANKLESS WATER HEATERS - SMALL BUT POWERFUL



The Stiebel Eltron Mini^™ tankless water heaters are designed for installation at the point-of-use. The Mini^™ heats water instantaneously as it flows through the unit. Stand-by heat-losses are completely eliminated. The efficient heating elements are controlled by a simple flow switch. Additionally, all Mini^™ water heaters are equipped with a safety high-limit with manual reset.
 

Flow controls and faucet aerators are highly recommended in conjunction with tankless water heaters. The Mini^™ 2-1 is internally restricted to 0.32 GPM. The Mini^™ 2-1, 2.5-1 and 3-1 models ship with a 0.5 GPM pressure compensating flow reducer / aerator. The Mini^™ 3.5-1 and 4-2 models ship with a 0.66 GPM pressure compensating flow reducer / aerator. All aerators are designed to fit most common faucets. No pressure relief valve, drains, or circulating pumps are needed.
 
Applications
 



The Stiebel Eltron Mini^™ tankless water heaters are ideal for restrooms or kitchenettes in an office or commercial / industrial setting:
 
Office Buildings Gas Stations * Stores * Schools * Malls * Hotels / Motels * Warehouses  Commercial Condominiums * Restaurants * Manufacturing Facilities
 
In a residential setting, suitable for the following applications:
Bathroom Sinks * Kitchen Sinks Laundry Areas * Small Cabins * Boats / RVs
  

Low Flow = Big Savings
Flow controls and faucet aerators are highly recommended in conjunction with tankless water heaters. The Mini^™ 2-1 is internally restricted to 0.32 GPM. The Mini^™ 2-1, 2.5-1 and 3-1 models ship with a 0.5 GPM pressure compensating flow reducer / aerator. The Mini^™ 3.5-1 and 4-2 models ship with a 0.66 GPM pressure compensating flow reducer / aerator. All aerators are designed to fit most common faucets. No pressure relief valve, drains, or circulating pumps are needed.

 
Any questions call 866-432-8123 or
go to http://www.houseneeds.com/heating/tankless-water-heaters/stiebel-eltron-electric-tankless-water-heater-mini

How to size a buffer tank

The primary application of a buffer tank is to reduce heat pump, chiller, or boiler short cycling. Hydronic buffer tanks are used in systems operating below the design load condition, which is most of the time, or in systems having several low BTU cooling or heating loads calling at different times. This can cause the heat pump or the boiler to short cycle, resulting in reduced operating efficiency and shorter equipment life.
The primary application for the HF-22 BT is to reduce low-mass modulating, condensing boiler short cycling. The high and low left side connections are used for boiler supply and return. The top connection is used to supply the distribution system and the low right connection is the return from the distribution system. If the top connection is piped to the line supplying the air purger and vent, the tank will be self venting.

Buffer Tank Sizing - Calculating Capacity

 

The Heat-Flo buffer tanks are a simple, cost effective way to improve overall system operating efficiency by reducing

unnecessary equipment short cycling. The recommended capacity or volume of a buffer tank is based on four variables.

1. The duration of the heating or cooling source “on time”. (minutes)

The desired length of “on time” for each run cycle depends on the type of equipment used. Heat pump and

chiller manufacturers typically recommend a minimum of 5 to 10 minutes on time, and boiler manufacturers may

recommend a minimum of 10 minutes “on time”. Check with your equipment manufacturer. Generally, the longer

the on time, the higher the overall operating efficiency.

2. The minimum rate of heat input. (BTU/HR)

This is based on the heat pump or chiller output, or the boiler output at the minimum firing rate if the boiler has a

variable input system that ramps input down as the demand decreases.

3. The minimum system load (BTU/HR)

This is the demand placed on the system with the smallest zone calling for heat.

4. The allowable tank temperature rise. (deg. F)

This varies depending on the type of heating or cooling system used, and on the design of the distribution system.

Chillers may require a tight, (6 deg. F), differential to assure good dehumidification and prevent freezing, heat

pumps may require a 10 deg. F differential to maintain a high COP, and boilers with hydronic heating distribution

systems may require a differential anywhere between 10 to 40 deg. F depending on the application.

The following formula determines the tank volume:

V=T X (Q heat input - Q min. heat load)

Tank temp. rise X 500

V = Buffer tank volume (gallons)

T = desired heat source “on cycle” (min.)

Q heat source = heat source output (BTU/HR)

Q min. heat load = heat output to minimum load

Tank temp rise (deg.F)

Water to Water Heat Pump Example: Town and Country Mechanical wants a minimum heat pump on time of 10 minutes.

The heat pump output is 46,500 BTU/HR. The smallest zone is a 7,000 BTU/HR bathroom. The allowable temperature

differential is 90 to 100 deg. F for the radiant heating zones.

V=10 X (46,500 - 7,000) = 79.0 Gallons minimum volume. Choose the HF-80BT buffer tank.

(100-90) x 500

Click here to see a drawing of a buffer tank application.

Heat-Flo Indirect Water Heaters

What is an indirect water heater?

An indirect is a storage tank with a heating coil built inside the tank. Hot water from any hydronic heating boiler is circulated through the coil inside the tank to heat all the water in the tank. The unit is piped like any other heating zone.

Why use an indirect water heater?

An indirect provides abundant hot water, low operating cost, and long life.

Abundant hot water

The Model 40 takes the full output of a 150,000 BTU boiler giving you over 150 gallons per hour of hot water @ 90 degree F rise, continuous! This compares to only 20 gallons per hour for a typical 4.5 KW electric water heater, and only 33 gallons per hour for a typical gas fired water heater. The Model HF-40 1st hour rating is 190 gallons. For an electric water heater to produce 190 gallons 1st hour, it would need to be a 187 gallon tank!

Low operating cost

Increased boiler on time increases boiler efficiency, and since there is no center flue like gas and oil fired water heaters, standby losses are extremely low. Operating costs of 50% less than an electric water heater are common.

Long life

No direct flame reduces lime accumulation and there are no electric elements to burn out. The units are all stainless steel construction. If you are installing or updating a hydronic heating system, or have an existing hydronic heating system, the indirect water heater is the right solution every time! Say goodbye forever to hot water shortfalls and high electric water heating costs.

Indirect water heater features and benefits include:

·           All plumbing connections are located on top for an easy installation.

·           All stainless steel tank and smooth tube heating coil for long life.

·           Full 2" plus of insulation for an extremely low heat loss.

·           A thermoplastic jacket that will not corrode or dent.

·           Standard Honeywell control and well for reliability and easy service.

·           Quality brass drain and T+P valves are factory installed.

·           Conforms to UL STD 174, Certified to CAN/CSA STD C22.2 No. 110-94.

30, 40, 60, 80 and 115 gallon units are available to suit both residential and commercial applications.

The 80 gallon unit is the way to go with hot tubs, spas, and multiple baths. The 115 gallon unit can be banked in commercial applications and produce an enormous amount of hot water, a perfect single system solution for multiple unit housing.

http://www.houseneeds.com/heating/indirect-storage-hot-water-tanks/heat-flo-single-heat-exchanger

 

 

 

 

VENTING PRODUCTS

Novavent Z-Flex Z Vent

NovaFlex Novavent is designed for use with boilers, high efficiency gas and oil heaters and water heaters where flue gases are vented under pressure. Novavent in 4 Inch contains a built-in, fail-safe gasket and locking band connection. No sealant is required.

Novavent Z Flex is the perfect Venting choice for the Gas Tankless Water Heaters and Gas Boilers that require 4" CAT III Stainless Steel Venting. When compared to plastic and other resin based materials used for venting systems, NovaVENT displays considerably lower thermal expansion and contraction making it much more resistance to stress corrosion cracking.

Novavent Z Flex has wall thimbles, vent terminators, straight vent lengths, elbows and more. We also have accessories such as drain tube kits and sealant. Will work for any other Category II, III and IV gas heating appliance too!

Z Flex Novavent vent pieces will work with Z Flex Z-Vent venting. Novavent is a less expensive alternative to Z-Vent and is also manufactured by Z-Flex which has over 30 years of proven reliability. Novavent has a thinner gauge metal than Z-Vent but still meets all applicable national building and fire codes and is UL listed 1738 for Category II,III, IV gas appliances. Novavent has wall thimbles, vent terminators, straight vent lengths, elbows and multiple adjustable lengths available.

Z-flex offers helpful venting videos on their website for some of their venting product. (see link)
http://www.z-flex.com/productcart/pc/viewContent.asp?idpage=50

To download the Z-vent brochure (go to this link) http://www.houseneeds.com/upload/pdf/zflex-zventinfo.pdf

To download the Z-vent manual (go to this link) http://www.houseneeds.com/upload/pdf/zflex-zventmanual.pdf

Z Flex Flexible Stainless Steel Liner Kits for Oil, Gas, Pellet or Wood



Z Flex all-fuel stainless steel flexible liner vent kit has a triple lock construction so it won’t pull apart during installation or separate under extreme heat conditions. Z flex Stainless Steel Flexible lining is intended for use as a chimney liner for masonry chimneys for oil, gas or wood fired residential heating appliances with a maximum heating of 1000 Degrees Fahrenheit. Larger diameters are available upon request. Z-flex is engineered to quickly conduct heat, assisting in a natural draft system.
Kit includes a limited lifetime warranty.

To download the liner kit installation guide (go to this link) http://www.houseneeds.com/upload/pdf/zflex-flexmanual.pdf

It is always best to Check with your local authority for applicable codes about the work you wish to perform and the necessity of permits before you begin your project.

Monoflo Tee the Unique System

When should I use monoflo tees when installing radiators and baseboard and why.

 

Monoflo systems are very unique systems because they have a single pipe around the basement and both the radiation supply and return pipe come off that same pipe.  Water always wants to take the path of least resistance when flowing. If you tried to install a monoflo system without creating pressure differences with specially designed tees the water would not flow to the radiation, it would just flow around the main pipe in the basement. All heat flow is dependent on pressure differences whether it be warm air, hot water or steam. High pressure goes to low pressure all the time, you cannot change that. As long as we create enough of a pressure change it all works fine. On the other hand is we do not create enough of a pressure change it does not work so well.

 

The invention of the monoflo tee is what makes this system work. It creates a pressure change large enough to make the water flow up or down into the radiation and back into the main loop pipe around the basement. You may ask what is the main difference between a series loop which is also one pipe around the basement and a monoflo or diverter tee system. A series loop will start at the boiler and go through all the radiation. It does not have tees off the main loop to each section of radiation, it is a continuous loop from one radiator to the next. The monoflo system has the tees to isolate each section of radiation. A series loop system if you want to shut off a section of baseboard or radiator with a valve you shut flow to the whole loop. The monoflo system if you shut down a valve on a section of baseboard or radiator the rest of the system works. The flow is affected slightly but it would still work just not as efficiently as the flow in the complete system depends on the flow through the monoflo tee and the radiation. There is a limit of 15K btuh on panel radiators for this piping arrangement.

The monoflo tee (see picture at the right) is designed to create a pressure difference between the supply tee and the return tee.  Let's look at the monoflo tee design.  The will have an arrow or a red ring to show direction of flow.


 The way this system works is as the water flows through the pipe it will pass the first tee as the straight pipe is the path of lest resistance. When the water hits the venturi (see picture to the right) in the second tee the amount of water that passes through is reduced but the velocity is increased. The water that is being backed up waiting to pass through the venturi is building pressure due to circulator still pumping. As the pressure builds it will increase until the the pressure at the first tee is great enough to overcome the pressure drop through the radiation connected to the set of tees. The water will circulate through the radiation and the gpm flowing through the radiation is also increased by the venturi effect. As the velocity increases through the venturi it will create a suction at the top of the venturi tee which added to the pressure buildup on the supply tee will flow the proper amount of water.

Click here to view PDF piping arrangement picture

To purchase monoflo tees on our Houseneeds.com web site please go to the below link:

http://www.houseneeds.com/heating/copper-bronze-brass-fittings/legend-monoflow-tee-venturi-tees

Please call us if you have any questions at 866-432-8123.