Low cost stainless steel multi-purpose hydronic system tanks for backup heat, hydraulic separation, buffer, or volume expander for use in hydronic, radiant, or chiller systems. Contact us for pricing or see the price list on our documents page.

Robotic welded stainless steel tank construction is used for both inner and outer tank  These professional grade insulated water tanks are designed for use with chillers, radiant heat, hydronic heating, & floor heating applications.

All-Stainless Steel
Buffer Tank or
Multi-Purpose Tanks

VCT60 58 Gallons

VCT 37 (37 gallons)

VCT19 (19 Gallons)

For vertical or horizontal installation.

VCT60 Tanks are 5 ft. tall and 22" diameter
See VCT60- buffer tank specs

VCT37 Tanks are 4 ft' 8" tall.18" diameter
See VCT37C buffer tank specs

VCT19 Tanks are 3 ft. 3" tall 18.5" diameter.
See VCT19 buffer tank specs

These small hydronic tanks can be used as a buffer tank, or to expand system volume, or as a backup heat tank. The VCT37C and VCT60 are perfect for combining multiple CX34 or CX50 units.

Heat exchanger tanks with indirect coils
are also available here.

What is a buffer tank?
Technically speaking a buffer tank is used for hydraulic separation whereby a pump circulates heated or chilled water into the tank from the source side, and a second pump circulates water out of, and back to the tank, on the load side. Buffer tanks are often used "smooth out" the operation of a boiler or chiller to prevent short cycling. With Chiltrix heat pumps, which are variable speed, short cycling is generally not an issue however due to Chiltrix unique controls, buffer tanks are needed whenever a Chiltrix heat pump interfaces with a radiant or floor loop. With Chiltrix there is a built-in pump, when used for floor or radiant heating, the Chiltrix controls are designed to maintain a specific temperature in the buffer tank but are not designed to circulate in the floor or radiant loop. Therefore, there must be a means of hydronic separation such as a buffer tank when using Chiltrix hydronic heat pumps for floor heat or radiant heating. In a Chiltrix heat pump system, an automatic seasonal valve can bypass the tank in cooling mode (when not being used for heating).

A buffer tank (or buffer vessel) will always have at least 4 water ports, two for the "source side", a supply and return, and two on the "load side", a supply and return. A vertical buffer tank is one that stands upright and this design allows strong thermal stratification. In some cases a horizontal buffer tank is needed for space requirements. In the horizontal design, less stratification will occur. In any case, the top of the tank will always be warmer than the bottom. Buffer tanks may be large or small, Chiltrix makes a small 37 gallon tank which is perfect for residential and small commercial applications including biomass, fermentation, thermal storage, chiller systems, hydronic heat pump use, hydronic separation, and use with wood boilers, gas boilers, or other type of hydronic or radiant heating systems that need a buffer tank.

This is an image of the VCT37 Chiltrix stainless steel buffer tank during production, it shows the "inner tank" before the insulation and outside stainless steel jacket has been added.

No corners have been cut, no shortcuts have been taken. This is a first-quality robot-welded buffer tank made from 100% stainless steel, inside and out.

What is a volume expander tank?

This is just what it sounds like - a tank that increases the water volume of the overall system. With Chiltrix heat pump chillers, we recommend at least 10-15 gallons of water in the system. For small systems where everything is close to the outdoor unit, a small tank may be needed to make sure that there is enough volume (gallons) in the system. Other than very small systems, Chiltrix only needs a buffer tank during floor or radiant heating operation and the Chiltrix system can a automatically activate an optional "seasonal valve" to bypass or isolate the buffer tank when operating in cooling mode.